Theoretical Prediction of Noble Gas Inserted Thioformyl Cations

Subscriber access provided by Angelo and Jennette | Volpe Library & Media Center

Article

Theoretical Prediction of Noble Gas Inserted Thioformyl Cations: HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe) Ayan Ghosh, Debashree Manna, and Tapan K. Ghanty J. Phys. Chem. A, Just Accepted Manuscript • Publication Date (Web): 24 Jun 2014 Downloaded from http://pubs.acs.org on June 25, 2014

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

The Journal of Physical Chemistry A is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Theoretical Prediction of Noble Gas Inserted Thioformyl Cations: HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe)†

Ayan Ghosh#, Debashree Manna‡, and Tapan K. Ghanty*,‡ #

‡

Laser and Plasma Technology Division, Beam Technology Development Group,

Bhabha Atomic Research Centre, Mumbai 400 085, INDIA. Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400 085, INDIA.

Abstract The existence of a new interesting insertion compounds, HNgCS+ (Ng = He−Xe), have been predicted theoretically through insertion of a noble gas atom into the thioformyl cation, HCS+. Second order Møller-Plesset perturbation theory (MP2), density functional theory (DFT), and coupled-cluster theory (CCSD(T)) based techniques have been used to explore the structure, energetics, charge distribution and harmonic vibrational frequencies of these compounds. These predicted ions are found to be energetically stable with respect to all the possible 2−body and 3−body dissociation pathways, except the 2−body channel leading to the global minimum products (HCS+ + Ng). Nevertheless, all these ions are found to be kinetically stable with a finite barrier height corresponding to their transition states, which are connected to their respective global minima products. The results obtained from charge distribution as well as atoms in molecules (AIM) analysis suggest that these ions can be best described as [HNg]+CS. Strong covalent character in the H−Ng bond is supported by the high positive energy value corresponding to the 3−body dissociation pathways. Thus, it might be possible to prepare the HNgCS+ ions in a glow discharge containing H2S, CO, and noble gas under cryogenic conditions through matrix isolation technique.

Keywords: Noble gas insertion compound; HCS+; Ab initio calculations; Structure and stability; Vibrational frequencies; AIM analysis †

Dedicated to Professor Markku Räsänen on his 65th Birthday Author to whom correspondence should be addressed. Electronic mail: [email protected]. Phone: 91-22-25595089. Fax: 91-22-25505151 *

1 ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1. Introduction Thioformyl cation, HCS+, also known as thiomethylium, was first observed with mass spectroscopic methods in the interstellar medium by Thaddeus et al.1 in 1981. They found four interstellar emission lines originating from HCS+ due to the rotational transitions in the microwave region. This observation was subsequently confirmed by measuring the J = 1 → 2 rotational transition due to the formation of HCS+ in a glow discharge containing H2S and CO gas mixture by Gudeman et al.2 Later, this work was extended by Bogey et al.,3 who have measured the additional lines up to J = 6 → 7 in the microwave spectrum of HCS+ ion for the generation of ground state fundamental constants such as rotational constant and quartic centrifugal distortion constant, etc. Botsch-wina and Sebald4 had reported the optimized structural parameters and spectroscopic properties of HCS+ ion using ab initio molecular orbital theory to rationalize these experimental data. More spectroscopic investigations were carried out to obtain the fundamental bands and hot bands by high resolution infrared spectroscopic studies.5−8 Due to its small size and linearity, the thioformyl cation generates an immense interest among experimental and theoretical researchers. It is valence isoelectronic with the cations like HCO+, HOC+, HN2+ etc.9−12 All these species including HCS+ are found to be highly abundant in the interstellar medium and species of potential interest in astrochemistry and astrophysics. Ionic complexes or clusters containing protonated ion are mostly found in plasmas and outer space environment, and can be easily produced in proton exchange reaction as a short lived reaction intermediates. Such kind of intermediates can form van der Waals (vdW) complexes with the noble gases. The vdW complexes between HCO+ and noble gas have been investigated through spectroscopic technique experimentally as well as theoretically.13−17 Apart from the ability of formation of vdW complexes, in recent years it has been demonstrated that noble gas atoms can participate18 in the conventional chemical bonding with other elements of the periodic table. In particular, after the discovery19 of first argon based noble gas insertion compound, HArF, with H−Ar covalent character, the field of noble gas chemistry has attracted considerable attention among researchers. Subsequently, several HNgY (Ng = Ar, Kr, and Xe; Y=electronegative element or group) species have been reported in the literature.19−32 Moreover, very recently, an argon containing noble gas molecular ion,

36

ArH+ have been detected by Barlow and coworkers in the Crab Nebula.33

Apart from the noble gas hydrides, bonding of a noble gas atom with various metal atoms has


Page 2 of 30

Page 3 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


also been reported.25,26,34−36 The binding energies of these novel metastable molecular species are found to be in between the vdW complexes and pure covalent compound. In general, noble gas inserted compounds including the hydrides are found to be stable only at very low temperature. However, from a study on the stability of noble gas hydrocarbons in an organic liquid-like environment using ab initio molecular dynamics simulation techniques, it has been found that the noble gas compounds may remain stable up to 150 K, which is well above the cryogenic temperature.37 Systematic investigations on the kinetic stability aspect of noble gas hydrides in different molecular environments and conditions have been studied recently.38,39 Of late, the preparation and characterization of three new halogenated xenon cyanides have been reported by Räsänen and his group.40 Moreover, the environmental effect on the vibrational properties of HNgCl molecules embedded in other noble gas (Ng′) matrices have also been investigated experimentally very recently by Khriachtchev and coworkers.41 They have also analyzed the matrix effects theoretically using a number of quantum chemical methods. In addition to the neutral species, various cationic and anionic insertion compounds have been predicted theoretically and some of them have also been observed experimentally under cryogenic conditions. In this context it may be interesting to note that the insertion of noble gas in molecular ions of HCO+, HN2+, H3O+, HBF+ and XCO+ (X= F and Cl) have been investigated theoretically42−46 by our group recently. However, as per our knowledge, the noble gas inserted thiomethylium (HCS+) has not been studied till now. The isovalency of HCS+ with HCO+, HN2+ and HBF+ has motivated us to investigate another set of novel interesting ionic molecular species, HNgCS+. In this paper we report detail theoretical analysis on HNgCS+ compounds, a new series in the family of noble gas insertion compounds. The theoretical methods such as second order Møller–Plesset perturbation theory (MP2), density functional theory (DFT), and coupled–cluster theory (CCSD(T)), have been employed to obtain the optimized structures, dissociation energies, vibrational frequencies, and other properties of HNgCS+ ions (Ng = He–Xe). The paper is organized as follows: first computational methodology is provided in Sec.2, then results are discussed in view of calculated values in Sec.3, and finally the concluding remarks are given in Sec.4.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

2. Computational Methodology The electronic structures of all the species have been calculated through ab initio molecular orbital method using GAMESS47 and MOLPRO 201248 program codes. The minima and the transition state structures of HNgCS+ ions have been optimized using MP2,49 DFT with Becke 3–parameter exchange and Lee–Yang–Parr Correlation (B3LYP),50,51 and CCSD(T)52 based methods. The structural optimizations have been performed with linear C∞v and Cs symmetry corresponding to the linear minima and planar transition state, respectively. We have utilized the energy adjusted Stuttgart effective core potentials53 and the corresponding (6s6p1d1f)/[4s4p1d1f] basis sets for Kr and Xe atoms and the standard split valence basis sets with polarization functions, viz., 6–311++G(2d,2p) for the H, He, C, Ne, S, and Ar atoms for all the DFT and MP2 calculations. The basis sets, aug−cc−pVTZ have been used for the later atoms in CCSD(T) method. To characterize the nature of the stationary point on the corresponding potential energy surface, MP2, DFT, and CCSD(T) methods have been employed to calculate the infrared harmonic vibrational frequencies numerically using finite difference approximation for all the HNgCS+ species in their respective minima and transition states. In order to understand the nature of bonding between the constituent atoms, the topological properties of the predicted ions have been calculated using the atoms−in−molecules (AIM)54 approach. 3. Results and Discussions 3.1 Optimized Geometrical Parameters of HNgCS+ Ions MP2, DFT, and CCSD(T) methods are employed to optimize the electronic structures of all the noble gas inserted thioformyl cations, HNgCS+, as well as all the fragments. By utilizing the above mentioned methods, the true minima and transition state geometries of the predicted HNgCS+ ions are obtained in their respective singlet potential energy surfaces. The optimized structures (shown in Figure 1) of HNgCS+ species exhibit linear geometry having C∞v symmetry at the minima and nonlinear but planar bent structure having Cs symmetry at the transition state. Detail structural parameters corresponding to both minimum and transition state geometries obtained by all the three methods are listed in Table 1. In general, it has been observed that in many cases the experimentally determined parameters are more closer with the CCSD(T) computed data rather than MP2 and DFT methods. Thus, the results obtained by CCSD(T) methods are discussed throughout the text unless otherwise mentioned. Here it may be noted that the CCSD T1 diagnostics values for


Page 4 of 30

Page 5 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


various minimum and transition state structures have been found to be below the limiting value of 0.02 indicating the adequacy of single reference based methods for the description of the present systems. The computed bond length values of H–Ng bonds in HNgCS+ have been found to be 0.766, 0.986, 1.284, 1.425, and 1.620 Å for HHeCS+, HNeCS+, HArCS+, HKrCS+, and HXeCS+ species respectively. The corresponding values calculated using MP2 and DFT methods agree well with the CCSD(T) results. The Ng–C bond length values are found to be 2.036, 2.585, 2.725, 2.757, and 2.872 Å for HHeCS+, HNeCS+, HArCS+, HKrCS+, and HXeCS+ ions, respectively. The CCSD(T) computed Ng–C bond length values are in close proximity with the respective MP2 values but somewhat different from the corresponding DFT calculated values. The calculated C–S bond length values are 1.524, 1.532, 1.530, 1.530 and 1.528 Å along the He–Ne–Ar–Kr–Xe series and these data reveal that the C–S bond distance remain almost the same for all the systems. In this context, a comparison can be made with respect to the H–Ng bond lengths between HNgCS+ and HNgCO+ ions42. The H–Ng bond length values are found to be 0.764, 0.967, 1.281, 1.417, and 1.610 Å in HHeCO+, HNeCO+, HArCO+, HKrCO+, and HXeCO+ ions, respectively, whereas the corresponding values in HNgCS+ ions are 0.766, 0.986, 1.284, 1.425, and 1.620 Å along the He–Ne–Ar–Kr–Xe series. This result indicates that the respective H–Ng bond lengths are quite close in both the present system and the HNgCO+ ions. Therefore, it can be concluded that the H–Ng bond in HNgCS+ ions are almost comparable in strength with the same in the HNgCO+ ions. In this regard, it may also be interesting to compare the H–Ng bond length values with reference to the HNgN2+ and HNgBF+ systems. It has been seen that the CCSD(T) calculated values for the H–Ng bond lengths are 0.765, 1.280, 1.416, and 1.607 Å along the He–Ar–Kr– Xe series in HNgN2+ ions and 0.771, 1.286, 1.422, and 1.620 Å for the respective H−Ng bond in the HNgBF+ species. It is evident from these data that the H–Ng bond length values are almost equivalent for all the ions discussed here, namely, HNgCO+, HNgN2+, HNgBF+, and HNgCS+, systems. Now, it is worthwhile to compare the bond distances of bare H–Ng+ ions with the corresponding values of the HNgCS+ ions. In bare H–Ng+ ions, the H–Ng bond distances are 0.776, 0.992, 1.282, 1.416, and 1.607 Å for HHe+, HNe+, HAr+, HKr+, and HXe+ respectively. The calculated bond distance values reveal that the H–Ng bond lengths are quite close with the corresponding bond lengths in HNgCS+ ions. This observation leads to a conclusion that there exists a strong bonding between the H and Ng atom in the HNgCS+ ions.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

To find out the nature of interaction between the Ng and C atoms, it is necessary to compare the present system with HNgBF+, HNgCO+, and HNgN2+ ions. The CCSD(T) computed Ng−B bond length values are 2.240, 2.943, 2.980, and 3.090 Å, corresponding to HHeBF+, HArBF+, HKrBF+, and HXeBF+ ions, respectively, while the Ng−N bond lengths in HNgN2+ ions are 2.138, 2.841, 2.922, and 3.093 Å along the series He, Ar, Kr, and Xe, respectively. Similarly, for the present systems the Ng–C bond length values are found to be 2.036, 2.585, 2.725, 2.757, and 2.872 Å along the He–Ne–Ar–Kr–Xe series, whereas the bond lengths of Ng−C in HNgCO+ ions are 2.221, 2.712, 2.911, 3.068, and 3.124 Å along the He, Ne, Ar, Kr, and Xe series. From the above results, it is clear that Ng−C bond lengths in HNgCS+ ions are smaller than Ng−B in HNgBF+, Ng−N in HNgN2+ and Ng−C in HNgCO+ bond lengths. Although atomic size decreases along the series B−C−N, the calculated shortest Ng-C bond distance in the present system suggest that the interaction between the Ng and C atom in HNgCS+ ions is the strongest among all the Ng−X interactions (X = B, C and N) discussed here. The electronegativity of oxygen is higher than that of sulphur and the atomic size of oxygen is smaller than that of sulphur, which makes sulphur atom more polarisable rather than oxygen leading to a shorter Ng−C bond in HNgCS+ ions. In this context, it is interesting to compare the Ng−C bond lengths in the linear NgCS+ ions in the ground state with the corresponding bond lengths in HNgCS+ ions. The CCSD(T) optimized Ng−C bond length values are found to be 2.902, 2.838, 2.456, 2.420, and 2.571 Å along the He–Ne–Ar– Kr–Xe series, in NgCS+ ions, which are shorter with respect to the respective bond lengths in HNgCS+ ions, except HNgHe+ and HNgNe+. It may be due to the positive charge transfer from the CS fragment to the HNg moiety resulting into a short and strong H−Ng bond and a weak Ng−C bond. The calculated value of C−S bond length in the HNgCS+ ions, as reported in Table 1, is found to be closer to the corresponding value for the bare CS fragment (1.550 Å). Therefore, the calculated values of H−Ng and C−S bond lengths in HNgCS+ ions clearly indicate that the metastable HNgCS+ species exist more formally as [HNg]+CS. More calculations have also been performed using MP2 methods with the same basis set (aug-ccpVTZ) as used in CCSD(T) calculations. However, the calculated bond length and bond dissociation energy values as obtained using MP2/6-311++G(2d,2p) and MP2/aug-cc-pVTZ methods are found to be very close. In the spirit of the work of Gerry and coworkers55 on the analysis of the noble gas atom containing chemical bond in terms of the covalent and van der Waals radii limits, denoted as Rcov and RvdW, respectively, we have been motivated to compare the R(H–Ng) and


Page 6 of 30

Page 7 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


R(Ng−C) bond lengths with respect to the Rcov and the RvdW. For a X−Y bond these limits can be defined as: Rcov = rcov(X) + rcov(Y) and RvdW = rvdW(X) + rvdW(Y). Standard rcov and rvdW values have been taken from the literature for the calculations of Rcov and RvdW. The computed covalent limit for the R(H−Ng) bond are 0.59, 0.89, 1.37, 1.47, and 1.71 Å for H−He, H−Ne, H−Ar, H−Kr, and H−Xe, respectively, and the respective vdW limits are 2.60, 2.74, 3.08, 3.22, and 3.36 Å.56,57 Again, the calculated covalent R(Ng−C) limits are 1.04, 1.34, 1.82, 1.92, and 2.16 Å for He−C, Ne−C, Ar−C, Kr−C, and Xe−C bonds, respectively, and the corresponding vdW limits are 3.10, 3.24, 3.58, 3.72, and 3.86 Å, respectively.56,57 It is clear from the above data that the H−Ng bond length values in HNgCS+ species are very close to the covalent limit whereas Ng−C bond length values are in between the covalent and the vdW limits. This suggests that the H and Ng atoms interacts very strongly whereas Ng and C atoms interacts relatively weakly in HNgCS+ ions. Furthermore, on this aspect, it is interesting to compare the H−Ng bond length of the predicted ion with the (NgHNg)+ ion59. This complex has been observed in noble gas matrices and investigated experimentally by mass spectrometric and matrix isolation techniques. Subsequently exhaustive theoretical study has also been carried out to support the experimental values for this (NgHNg)+ systems. The H−Ng bond length values are 1.501, 1.662, and 1.845 Å for ArHAr+, KrHKr+, and XeHXe+ species, respectively, calculated by CCSD(T) method, which are larger than the corresponding bond length values in HNgCS+ ions. The results further confirm that there exists a strong interaction between the H and Ng atoms in HNgCS+, rather than the same in (NgHNg)+ ions. Geometry of the HNgCS+ ions transforms from linear to non−linear bent structure from minima to the saddle point. There is a slight decrease in H−Ng bond length and increase in Ng−C bond length due to the H−Ng−C bending mode in the transition state geometry for the present systems. The C−S bond lengths also increase from minima to transition state geometries for all the ions except HNeCS+. The H−Ng−C bond angles change drastically from 180° to ~100° except HNeCS+, and the Ng−C−S bond angles are almost similar for the minima and the transition state structures. 3.2 Analysis of Harmonic Vibrational Frequencies of HNgCS+ Ions The harmonic vibrational frequencies along with the corresponding IR intensity calculated using MP2, DFT, and CCSD(T) methods are reported in Table 2. In case of noble gas containing complexes, the vibrational frequencies obtained by the MP2 method generally



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

resemble well with the experimentally observed values. Moreover, for the HNgCS+ species the MP2 calculated frequency values are more closer to the corresponding CCSD(T) values. Therefore, in this section, MP2 computed vibrational frequencies are discussed unless otherwise mentioned. There exists three non−degenerate stretching modes (viz., H−Ng stretch, Ng−C stretch, and C−S stretch) and two doubly degenerate bending modes (viz., H−Ng−C bend, and Ng−C−S bend) in the minimum energy state of the predicted HNgCS+ ion. The maximum frequency has been found for the H−Ng stretching mode, and the range of the vibrational frequencies is within 3399 − 2278 cm−1 for the HNgCS+ ions. The Ng−C stretching frequencies have been found in the range of 122 − 417 cm−1, where, Xe−C stretching shows the shortest value (122 cm−1) as compared to the largest one, 417 cm−1 for the He−C stretching, among all the Ng−C modes. The infrared stretching frequency values are found in the range of 1360 − 1330 cm−1 for the C−S stretching in HNgCS+ species and it remains quite close for all the ions considered here, irrespective of the Ng atom present in the system. In HCS+ ion, there exists intense H−C stretching vibrational mode at 3296 cm−1, C−S stretching vibrational frequency at 1375 cm−1 and a doubly degenerate H−C−S bending mode at 765 cm−1. Therefore, it is quite obvious that after insertion of noble gas into the thioformyl cation, the C−S stretching frequency is expected to change in the HNgCS+ ion as compared to that in the bare HCS+ ion. In this aspect, it is also interesting to compare the H−Ng stretching frequency values of HNgCS+ ions with respect to the bare HNg+ ions. The H−Ng stretching frequency values for the bare HNg+ ions are 3259, 2930, 2652, 2574, and 2340 cm−1 along the He–Ne–Ar–Kr–Xe series, which are almost comparable with the respective frequency values of HNgCS+ ions. During the analysis of the vibrational frequency, it is observed that the vibrational modes, especially the stretching vibrational modes couple with each other strongly. Therefore, Boatz and Gordon58 approach has been adopted to partition the normal coordinate frequencies into individual internal coordinates. All the harmonic vibrational frequencies corresponding to the individual internal coordinate in HNgCS+ ion are listed in Table 3. The MP2 computed force constant (k) values for H−Ng bonds are 548.0, 518.1, 403.2, 372.9, and 305.9 Nm−1 for the He, Ne, Ar, Kr, and Xe containing HNgCS+ species, respectively. These high force constant values suggest that there exists a strong and rigid


Page 8 of 30

Page 9 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


bond between the H and Ng atom in HNgCS+ ion. These results are in excellent agreement with the structural parameters, which in turn is further supported by the dissociation energies. 3.3 Thermodynamic and Kinetic Stability of HNgCS+ Ions The most probable unimolecular dissociation channels have been discussed here to get an idea about the stability of the predicted HNgCS+ ions. In order to calculate the accurate energy, the following dissociation channels are considered:

HNgCS+ →

HCS+ + Ng

(1)

HNg+ + CS

(2)

HNg + CS+

(3)

H + NgCS

+

(4) +

(5)

H + Ng + CS

(6)

H + Ng + CS +

To determine the thermodynamic and kinetic stability of the predicted HNgCS+ ions, the energies corresponding to all these probable dissociation channels are listed in the Table 4. In this regard, we have considered four 2−body dissociation (channels 1− 4) and two 3−body dissociation (channels 4−5) pathways for the HNgCS+ ions. Among all these four dissociation channels, the first one gives rise to the global minimum products and the remaining channels lead to the local minimum products, on the potential energy surface. The calculated data reported in Table 4 indicate that the predicted HNgCS+ ions are thermodynamically unstable with respect to the global minimum products (HCS+ and Ng), and are 518.3, 530.6, 347.2, 266.9, 201.9 kJ mol−1 higher in energy along the series He–Ne–Ar–Kr–Xe, as calculated using CCSD(T) method. The CCSD(T) computed energy values for the channel 2 are found to be 101.7, 62.2, 72.5, 76.6, and 77.9 kJ mol−1 for HHeCS+, HNeCS+, HArCS+, HKrCS+, and HXeCS+ ions, respectively, leading to endothermic dissociations. In this context, it is interesting to compare the corresponding dissociation energy values for the analogous HNgCO+ systems (15.0, 28.8, 29.5, and 29.1 kJ mol−1 along the He–Ar–Kr–Xe series, at CCSD(T) method). More endothermic behavior for the channel 2 of the HNgCS+ ions as compared to the HNgCO+ species suggests that the interaction between Ng and C atoms are stronger in HNgCS+ ions as compared to that in the HNgCO+ species. The computed energy corresponding to the dissociation channels 3 and 4 have been found to be 75.8, 63.3, 246.4, 326.3, 390.9 and 74.4, 60.3, 223.0, 254.1, 259.2 kJ mol−1 along the He, Ne, Ar, Kr, and Xe series, respectively. The CCSD(T) dissociated energy



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

values corresponding to the 3−body dissociation channels 5 and 6 are found to be 75.8, 63.5, 246.9, 327.2, 392.1 kJ mol−1 and 298.2, 285.9, 469.2, 549.9, 614.5 kJ mol−1 for HHeCS+, HNeCS+, HArCS+, HKrCS+, and HXeCS+ ions, respectively. Two 2−body dissociation channels (3 and 4) and two 3−body dissociation channels (5 and 6) show high positive energy values, which indicate that the predicted ions are more stable as compared to the respective dissociated products. Furthermore, in this context, it is important to compare the dissociation energy values of the present system with the experimentally characterized NgHNg+ cations.59−63 The energies corresponding to the dissociation channel NgHNg+ → NgH+ + Ng, are in the range of 64−66 kJ mol−1 along the Ar−Kr−Xe series in NgHNg+ cations, which are smaller than that of the respective energies (73−78 kJ mol−1 for Ar, Kr, Xe series in HNgCS+) for the present system. Thus, it may be possible to prepare these metastable HNgCS+ ions by electron bombardment matrix isolation technique at cryogenic temperatures. Now, it is worthwhile to evaluate the kinetic stability of the predicted HNgCS+ ions, which are thermodynamically unstable with respect to the global minimum products (Ng + HCS+). The energy differences between the HNgCS+ species and the corresponding transition states, the so called “barrier heights” have been calculated for the predicted HNgCS+ ions. The CCSD(T) computed barrier heights (without any zero point energy correction) have been found to be 13.3, 19.5, 27.5, and 33.9 kJ mol-1 for the HHeCS+, HArCS+, HKrCS+ and HXeCS+ ions, respectively, indicating their metastable nature with respect to the global minimum products, and hence it might be possible to prepare and identify these predicted ions experimentally. We have also computed the intrinsic reaction coordinates (IRC) connecting the meta-stable minima and the global minima products through transition state, and the reaction path ways are depicted in Figure 2. Here it is interesting to note that the DFT calculated barrier heights for all these ions are relatively higher than the corresponding values obtained from MP2 and CCSD(T) methods. In this context it is important to mention that DFT results have been found to be more realistic as far as the energetics of noble gas compounds is concerned.64 Furthermore, to determine the accurate barrier heights, zero−point energy (ZPE) correction parameter has been evaluated along with the barrier heights. The MP2 calculated barrier heights (zero point energy corrected barrier heights) are 12.5 (6.4), 21.3 (16.1), 29.3 (23.9), and 34.3 (29.1) kJ mol−1 for the HHeCS+, HArCS+, HKrCS+ and HXeCS+ ions, respectively, and the corresponding DFT computed values are found to be 32.7 (27.3), 29.2 (24.3), 36.9 (31.6), and


Page 10 of 30

Page 11 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


37.4 (32.5) kJ mol−1. Here it may be noted that the barrier height of the HNeCS+ is reasonably small. This is due to the very less chemical reactivity of Ne atom, which has been discussed recently by Grandinetti.65 Since the calculated barrier heights are quite high, particularly for the Ar, Kr, and Xe containing HNgCS+ ions, it is clear that these kinetically stable species might be observed at cryogenic conditions, like the other noble gas containing hydrides that have been detected experimentally in recent years. 3.4 Charge Distribution Analysis of HNgCS+ Ions In order to obtain the nature of bonding exists between the constituent atoms or fragments in the complex, it is essential to know the partial atomic charges presents on these atoms or fragments. The MP2 (DFT) computed partial atomic charges on the constituent atoms of the HNgCS+ species obtained from the Mulliken population analysis have been reported in Table 5, which indicates that the set of charges calculated by using two different methods are almost equivalent. Now onwards, the DFT calculated partial charges are considered for further discussion. The partial atomic charges (q) evaluated for the constituent atoms in HCS+ ion are qH = 0.309, qC = 0.427, and qS = 0.264 for H, C, and S atoms, respectively. From the reported results it is clear that significant redistribution of the charges has taken place after the insertion of a noble gas atom into the thioformyl cation, HCS+. The partial charge on H atom changes to 0.541, 0.563, 0.348, 0.229, and 0.160 along the He–Ne–Ar–Kr–Xe, series in HNgCS+ ions. Except HXeCS+ ions, the charge on the C atom is found to be negative and the qC value changes to −0.023, −0.106, −0.042, −0.171, and 0.035, in HHeCS+, HNeCS+, HArCS+, HKrCS+, and HXeCS+ ions, respectively. Subsequently, the partial charges on S atoms (qS) are found to be 0.215, 0.186, 0.101, 0.295, and 0.078 for He, Ne, Ar, Kr, and Xe series, in HNgCS+ complexes. The charges possessed by the noble gas atoms are found to be 0.267, 0.358, 0.593, 0.647, and 0.727, along the He–Ne–Ar–Kr–Xe, series in HNgCS+ ions. In the bare HNg+ ions the charge acquired by the H atoms are 0.641, 0.666, 0.405, 0.319, and 0.218 while going from He to Xe, which are almost comparable with the corresponding values in HNgCS+ complexes. In this stage, it is interesting to compare the overall charge on the HNg+ fragments in HNgCS+ ion with respect to the bare HNg+ ions. The total cumulative charge on the HNg+ moiety are 0.808, 0.921, 0.941, 0.876, and 0.887 for the HHe+, HNe+, HAr+, HKr+, and HXe+ fragments respectively in HNgCS+ ions, whereas unit positive charge resides on the bare



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

HNg+ ions. After the insertion of the noble gas atoms in the thiomethylium ion, extensive charge redistribution has taken place due to substantial amount of charge transfer from CS+ to HNg fragment in the HNgCS+ complexes. There is an increase in magnitude in the charge separation in the transition state as compared to that in the metastable state for all the predicted HNgCS+ ions. Although the Mulliken population analysis is one of the most popular methods to obtain the electronic charge distribution in a chemical system, NBO calculations have also been performed for the minimum energy structures using the MOLPRO program. The NBO analysis have been performed using MP2 and DFT methods with 6−311G++(2d,2p) basis sets to obtain the partial atomic charge on the constituent atoms of the HNgCS+ ions and results are also represented in Table 5. Indeed, the NBO analysis scheme indicates that the C−S bond is polar covalent in nature. On the other hand the Ng-C bonds show reasonably ionic character. However, the predicted HNgCS+ ion exists as a complex of HNg+ and CS species according to the results obtained using NBO and Mulliken population analysis. 3.5 Atom in Molecules (AIM) Analysis of HNgCS+ Ions For a better understanding of the nature of the chemical bond exits between the constituent atoms AIM approach developed by Bader54 has been adopted. AIM makes a bridge between the electron charge density and the quantum chemical concept, and is highly efficient and useful for description of many chemical systems. According to the AIM model, if the atomic volumes of two atoms are overlapping with each other through inter atomic surfaces then there exists a bond between them, i.e., based on the topology of the electron density a bond path is considered as the line along which the electron density is the maximum with respect to a neighboring line. In space, a critical point is defined as the point where the gradient of the electron density is zero (i.e., ∇ρ = 0) implying the electron density is the maximum with respect to the surrounding and a (3,−1) point is referred to as bond critical point (BCP) where two of the eigenvalues of the Hessian matrix are negative. The AIM method also allows one to locate and distinguish different types of interactions existing between the constituent atoms in a molecular species. The AIM properties have been calculated by employing MP2 and DFT (B3LYP) methods with 6−311++G(2d,2p) basis sets along with Stuttgart valence basis sets (with ECP). To obtain the topological parameters in HNgCS+ ions, we have applied AIM approach and analyzed the nature of chemical bonds exist in between the constituent atoms in the HNgCS+


Page 12 of 30

Page 13 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


complexes. Table 6 lists the most important quantities required for the analysis of a chemical bond viz., the electron density (ρ) and it’s Laplacian (∇2ρ) at the bond critical points (BCPs) of the molecules concerned. Normally, ∇2ρ < 0 is referred to the shared type of interactions resulting into covalent bonding, whereas ∇2ρ > 0 value is associated with the non-shared type of interactions leading to ionic, hydrogen, and vdW bonds. All the predicted HNgCS+ ions show high negative values at the BCPs corresponding to the H−Ng bonds, which imply that covalent character is more for these bonds. The covalent nature of the H−Ng bonds is further confirmed with the observation of high BCP electron density values for the H−Ng bonds. In comparison to H−Ng bonds, low positive values for ∇2ρ as well as low ρ values are obtained for the Ng−C bonds. One of the most important quantity in the AIM analysis is to compute the local energy density, which is represented as Ed(r) = G(r) + V(r), where G(r) and V(r) correspond to local kinetic and potential energy densities, respectively. The sign of Ed(r) predicts whether accumulation of charge at a given point, r, is stabilizing [Ed(r) < 0] or destabilizing [Ed(r) >0]. A negative value of Ed(r) refers that V(r) dominates over G(r) and the electron density accumulates in the bond region resulting in a covalent bond. The MP2 computed Ed(r) values for H−Ng bonds are −0.694, −0.725, −0.271, and −0.191 for HHeCS+, HNeCS+, HArCS+, and HKrCS+ ions respectively, which emphasis that H−Ng bonds are stable with respect to the accumulation of electron density at the bond region, leading to covalent bonding between the H and Ng atoms. The Ed(r) values corresponding to Ng−C bonds are −0.002, 0.002, 0.001, 0.001, and −0.001 for the HHeCS+, HNeCS+, HArCS+, HKrCS+, and HXeCS+ ions respectively. Moreover, the calculated Ed(r) values of the C−S bonds in all the predicted systems show high negative values, indicating that the bonds are stabilizing in nature. Considering all the computed BCP properties, it is evident that the H−Ng bonds show high degree of covalency, whereas, all the calculated BCP values for the Ng−C bonds show that a reasonable amount of ionic character exists between the Ng and C atoms leading to an ion−dipole type interaction. Nevertheless, for the He-C bond a small negative value of Ed(r), a comparatively higher value of BCP ρ and larger He-C bond energy indicate a small amount of covalency in the He-C bond. The above calculated properties strongly indicate that the HNgCS+ ions are chemically bound cations rather than vdW complexes.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

4. Concluding Remarks In summary, an unique series of noble gas inserted compound, HNgCS+, have been predicted theoretically through investigations of the structural parameters, harmonic vibrational frequencies, energetics

as well as charge distribution data by employing MP2, DFT,

CCSD(T) methods. The calculated results show that the predicted species are thermodynamically unstable in nature in the singlet potential energy surface with respect to the global minima products (HCS+ and Ng), however, the barrier heights corresponding to the transition states connecting the HNgCS+ ions and the global minimum products, are found to be quite high for all of the predicted ions (except HNeCS+) ensuring their kinetic stability. Moreover, high positive energy values have been found for the remaining dissociation channels of HNgCS+ ions. From Mulliken analysis, NBO calculations as well as AIM approach, it is evident that a strong covalent bonding exists between the H and Ng atom, whereas Ng−C is found to be a weak bond, which are also reflected from the high positive energy value for all the 2-body and 3−body dissociation channels, except channel 1. The calculated bond energies of the predicted ions are higher than that of experimentally investigated NgHNg+ ions detected through electron bombardment and matrix isolation technique. Therefore, these noble gas inserted thioformyl cation, HNgCS+, particularly, Ar, Kr and Xe containing species may be observed experimentally through electron bombardment in a gas discharge consisting of H2S, CO, and noble gases at cryogenic temperature and can be characterized by spectroscopic techniques.

Acknowledgments The authors would like to thank the Computer Division, BARC for providing computational facilities and support. We would like to thank Dr. A. K. Nayak, Dr. A. K. Das, Dr. L. M. Gantayet, Dr. S. K. Ghosh, and Dr. B. N. Jagatap for their kind interest and continuous encouragements.

References 1. Thaddeus, P.; Guélin, M.; Linke, R. A. Three New ‘Nonterrestrial’ Molecules. Astrophys. J. 1981, 246, L41−L45.


Page 14 of 30

Page 15 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2. Gudeman, C. S.; Haese, N. N.; Piltch, N. D.; Woods, R. C. The Observation of the J = 1−2 Transition of HCS+ in a Laboratory Glow Discharge. Astrophys. J. 1981, 246, L47−L49. 3. Bogey, M.; Demuynck, C.; Destombes, J. L.; Lemoine, B. Millimeter Wave Spectrum of HCS+1. J. Mol. Spectrosc. 1984, 107, 417−418. 4. Botsch-wina, P.; Sebald, P. Spectroscopic Properties of CS and HCS+ from Ab Initio Calculations. J. Mol. Spectrosc. 1985, 110, 1−18. 5. Davies, P. D.; Rothwell, W. J. Infrared Laser Spectroscopy of the ν2 Mode of HCS+. J. Chem. Phys. 1985, 83, 1496−1498. 6. Rosenbaum, N. H.; Owrutsky, J. C.; Tack, L. M.; Saykally, R. J. Measurement of the ν1 Vibration−Rotation Spectrum of the Thioformyl Ion (HCS+) by Velocity Modulation Laser Spectroscopy. J. Chem. Phys. 1985, 83, 4845−4848. 7. Rosenbaum, N. H.; Owrutsky, J. C.; Saykally, R. J. Velocity Modulation Infrared Laser Spectroscopy of HCS+: Analysis of Hot Bands and Perturbations. J. Mol. Spectrosc. 1989, 133, 365−382. 8. Tang, J.; Saito, S. Microwave Spectra of the Isotopomers of HCS+ and Its Substitution Structure. Astrophys. J. 1995, 451, L93−L95. 9. Buhl, D.; Snyder, L. E. Unidentified Interstellar Microwave Line. Nature (London). 1970, 228, 267. 10. Turner, B. E. A New Interstellar Line with Quadrupole Hyperfine Splitting. Astrophys. J. 1974, 193, L83−L87. 11. Green, S.; Montgomery, J. A., Jr.; Thaddeus, P. Tentative Identification of U93.174 as the Molecular Ion N2H+ Astrophys. J. 1974, 193, L89−L91. 12. Thaddeus, P.; Turner, B. E. Confirmation of Interstellar N2H+. Astrophys. J. 1975, 201, L25−L26. 13. Nizkorodov, S. A.; Maier, J. P.; Bieske, E. J. The Infrared Spectrum of He−HCO+. J. Chem. Phys. 1995, 103, 1297−1302. 14. Nizkorodov, S. A.; Dopfer, O.; Meuwly, M.; Maier, J. P.; Bieske, E. J. Mid−Infrared Spectra of the Proton−Bound Complexes Nen−HCO+ (n = 1, 2). J. Chem. Phys. 1996, 105, 1770−1777. 15. Nizkorodov, S. A.; Dopfer, O.; Ruchti, T.; Meuwly, M.; Maier, J. P.; Bieske, E. J. Size Effects in Cluster Infrared Spectra: the ν1 Band of Arn−HCO+ (n = 1−13). J. Phys. Chem. 1995, 99, 17118−17129.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

16. Ohshima, Y.; Sumiyoshi, Y.; Endo, Y. Rotational Spectrum of the Ar−HCO+ Ionic Complex. J. Chem. Phys. 1997, 106, 2977−2979. 17. Seki, K.; Sumiyoshi, Y.; Endo, Y. Rotational Spectrum of the Kr−HCO+ Ionic Complex. Chem. Phys. Lett. 2000, 331, 184−188. 18. Grochala, W. Atypical Compounds of Gases, Which Have Been Called Noble. Chem. Soc. Rev. 2007, 36, 1632−1655. 19. Khriachtchev, L.; Pettersson, M.; Runeberg, N.; Lundell, J.; Räsänen, M. A Stable Argon Compound. Nature (London). 2000, 406, 874−876. 20. Khriachtchev, L.; Pettersson, M.; Lignell, A.; Räsänen, M. A More Stable Configuration of HArF in Solid Argon. J. Am. Chem. Soc. 2001, 123, 8610−8611. 21. Pettersson, M.; Khriachtchev, L.; Lundell, J.; Räsänen, M. In Inorganic Chemistry in Focus II; Meyer, G.; Naumann, D.; Wesemann, L. Eds.; Wiley-VCH, New York. 2005, p 15. 22. Gerber, R. B. Formation of Novel Rare−Gas Molecules in Low−Temperature Matrices. Annu. Rev. Phys. Chem. 2004, 55, 55−78. 23. McDowell, S. A. C. Studies of Neutral Rare-Gas Compounds and their Non−Covalent Interactions with Other Molecules. Curr. Org. Chem. 2006, 10, 791−803. 24. Khriachtchev, L.; Isokoski, K.; Cohen, A.; Räsänen, M.; Gerber, R. B. A Small Neutral Molecule with Two Noble−Gas Atoms: HXeOXeH. J. Am. Chem. Soc. 2008, 130, 6114−6118. 25. Ghanty, T. K. Insertion of Noble−Gas Atom (Kr and Xe) into Noble Metal Molecules (AuF and AuOH): Are they Stable? J. Chem. Phys. 2005, 123, 074323. 26. Ghanty, T. K. How Strong is the Interaction between a Noble Gas Atom and a Noble Metal Atom in the Insertion Compounds MNgF (M = Cu and Ag, and Ng = Ar, Kr, and Xe)? J. Chem. Phys. 2006, 124, 124304. 27. Jayasekharan, T.; Ghanty, T. K. Structure and Stability of Xenon Insertion Compounds of Hypohalous Acids, HXeOX [X = F, Cl, and Br]: An Ab Initio Investigation. J. Chem. Phys. 2006, 124, 164309. 28. Jayasekharan, T.; Ghanty, T. K. Insertion of Rare Gas Atoms into BF3 and AlF3 Molecules: An Ab Initio Investigation. J. Chem. Phys. 2006, 125, 234106. 29. Jayasekharan, T.; Ghanty, T. K. Significant Increase in the Stability of Rare Gas Hydrides on Insertion of Beryllium Atom. J. Chem. Phys. 2007, 127, 114314.


Page 16 of 30

Page 17 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


30. Justik, M. W. Halogens and Noble Gases. Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem. 2009, 105, 165−176. 31. Grochala, W.; Khriachtchev, L.; Räsänen, M. Noble−Gas Chemistry. In Physics and Chemistry at Low Temperatures; Khriachtchev, L., Ed.; CRC Press: Boca Raton, FL, 2011; Chapter 13, p 419. 32. Khriachtchev, L.; Räsänen, M.; Gerber, R. B. Noble−Gas Hydrides: New Chemistry at Low Temperatures. Acc. Chem. Res. 2009, 42, 183−191. 33. Barlow, M. J.; Swinyard, B. M.; Owen, P. J.; Cernicharo, J.; Gomez, H. L.; Ivison, R. J.; Krause, O.; Lim, T. L.; Matsuura, M.; Miller, S.; Olofsson, G.; Polehamton, E. T. Detection of a Noble Gas Molecular Ion

36

ArH+, in the Crab Nebula. Science. 2013,

342, 1343−1345. 34. Seidel, S.; Seppelt, K. Xenon as a Complex Ligand: The Tetra Xenono Gold(II) Cation in AuXe42+(Sb2F11−)2. Science. 2000, 290, 117−118. 35. Pyykkö, P. Predicted Chemical Bonds between Rare Gases and Au+. J. Am. Chem. Soc. 1995, 117, 2067−2070. 36. Schroder, D.; Schwarz, H.; Hrusak, J.; Pyykkö, P. Cationic Gold(I) Complexes of Xenon and of Ligands Containing the Donor Atoms Oxygen, Nitrogen, Phosphorus, and Sulfur. Inorg. Chem. 1998, 37, 624−632. 37. Tsiviona, E.; Gerber, R. B. Stability of Noble-gas Hydrocarbons in An Organic Liquid-Like Environment: HXeCCH in Acetylene. Phys. Chem. Chem. Phys. 2011, 13, 19601−19606. 38. Tsuge, M.; Berski, S.; Stachowski, R.; Räsänen, M.; Latajka, Z.; Khriachtchev, L. High Kinetic Stability of HXeBr upon Interaction with Carbon Dioxide: HXeBr···CO2 Complex in a Xenon Matrix and HXeBr in a Carbon Dioxide Matrix. J. Phys. Chem. A 2012, 116, 4510−4517. 39. Gerber, R. B.; Tsivion, E.; Khriachtchev, L.; Räsänen, M. Intrinsic Lifetimes and Kinetic Stability in Media of Noble−Gas Hydrides. Chem. Phys. Lett. 2012, 545, 1−8. 40. Arppe, T.; Khriachtchev, L.; Lignell, A.; Domanskaya, A. V.; Räsänen, M. Halogenated Xenon Cyanides ClXeCN, ClXeNC, and BrXeCN. Inorg. Chem. 2012, 51, 4398−4402. 41. Kalinowski, J.; Gerber, R. B.; Räsänen, M.; Lignell, A.; Khriachtchev, L. Matrix Effect on Vibrational Frequencies: Experiments and Simulations for HCl and HNgCl (Ng = Kr and Xe). J. Chem. Phys. 2014, 140, 094303.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

42. Jayasekharan, T.; Ghanty, T. K. Theoretical Prediction of HRgCO+ Ion (Rg = He, Ne, Ar, Kr, and Xe). J. Chem. Phys. 2008, 129, 184302. 43. Jayasekharan, T.; Ghanty, T. K. Theoretical Investigation of Rare Gas Hydride Cations: HRgN2+. (Rg = He, Ar, Kr, and Xe). J. Chem. Phys. 2012, 136, 164312. 44. Ghosh, A.; Manna, D.; Ghanty, T. K. Theoretical Prediction of Rare Gas Inserted Hydronium Ions: HRgOH2+. J. Chem. Phys. 2013, 138, 194308. 45. Sirohiwal, A.; Manna, D.; Ghosh, A.; Jayasekharan, T.; Ghanty, T. K. Theoretical Prediction of Rare−Gas−Containing Hydride Cations: HRgBF+ (Rg = He, Ar, Kr, and Xe). J. Phys. Chem. A 2013, 117, 10772−10782. 46. Manna, D.; Ghosh, A.; Ghanty, T. K. Theoretical Prediction of XRgCO+ Ions: (X = F, Cl, and Rg = Ar, Kr, Xe. J. Phys. Chem. A 2013, 117, 14282−14292. 47. Schmidt, M. W.; Baldridge, K. K.; Boatz, J. A.; Elbert, S. T.; Gordon, M. S.; Jensen, J. H.; Koseki, S.; Matsunaga, N.; Nguyen, K. A.; Su, S. et al. General Atomic and Molecular Electronic Structure System. J. Comput. Chem. 1993, 14, 1347−1363. 48. Werner, H.-J.; Knowles, P. J.; Knizia, G.; Manby, F. R.; Schützet, M.; Celani, P.; Korona, T.; Lindh, R.; Mitrushenkov, A.; Rauhut, G. et al. MOLPRO, version 2012.1, a Package of ab initio Programs, 2012, see http://www.molpro.net. 49. Frisch, M. J.; Head-Gordon, M.; Pople, J. A. A Direct MP2 Gradient Method. Chem. Phys. Lett. 1990, 166, 275−280. 50. Becke, A. D. A New Mixing of Hartree−Fock and Local Density−Functional Theories. J. Chem. Phys. 1993, 98, 1372−1377. 51. Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B Development of the Colle−Salvetti Correlation−Energy Formula into a Functional of the Electron Density. 1988, 37, 785−789. 52. Hampel, C.; Peterson, K.; Werner, H.-J. A Comparison of the Efficiency and Accuracy of the Quadratic Configuration Interaction (QCISD), Coupled Cluster (CCSD) and Brueckner Couple Cluster (BCCD) Methods. Chem. Phys. Lett. 1992, 190, 1−12. 53. Andrae, D.; Haussermann, U.; Dolg, M.; Stoll, H.; Preuss, H. Energy-adjusted Ab Initio Pseudopotentials for the Second and Third Row Transition Elements. Theor. Chim. Acta. 1990, 77, 123−141. 54. Bader, R. F. W. Atoms in Molecules−A Quantum Theory; Oxford University Press, Oxford, 1990.


Page 18 of 30

Page 19 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


55. Cooke, S. A.; Gerry, M. C. L. XeAuF. J. Am. Chem. Soc. 2004, 126, 17000-17008, and references therein. 56. Cordero, B.; Gómez, V.; Platero-Prats, A. E.; Revés, M.; Echeverría, J.; Cremades, E.; Barragán, F.; Alvarez, S. Covalent Radii Revisited. Dalton Trans. 2008, 2832−2838. 57. Bondi, A. van der Waals Volumes and Radii. J. Phys. Chem. 1964, 68, 441−451. 58. Boatz, A.; Gordon, M. S. Decomposition of Normal−Coordinate Vibrational Frequencies. J. Phys. Chem. 1989, 93, 1819−1826. 59. Lundell, J. Density Functional Approach on Ground State RgH+ and RgHRg+ (Rg = Ar, Kr, Xe) Ions. J. Mol. Struct. 1995, 355, 291−297. 60. Fridgen, T. D.; Parnis, J. M. Electron Bombardment Matrix Isolation of Rg/Rg′/Methanol Mixtures (Rg = Ar, Kr, Xe): Fourier−Transform Infrared Characterization of the Proton−Bound Dimmers Kr2H+, Xe2H+, (ArHKr)+ and (ArHXe)+ in Ar Matrices and (KrHXe)+ and Xe2H+ in Kr Matrices. J. Chem. Phys. 1998, 109, 2155−2161. 61. Fridgen, T. D.; Parnis, J. M. Density Functional Theory Study of the Proton−Bound Rare−Gas Dimmers Rg2H+ and (RgHRg′)+ (Rg = Ar, Kr, Xe): Interpretation of Experimental Matrix Isolation Infrared Data. J. Chem. Phys. 1998, 109, 2162−2168. 62. Lundell, J.; Pettersson, M.; Räsänen, M. The Proton−Bound Rare Gas Compounds (RgHRg′) (Rg = Ar, Kr, Xe) − A Computational Approach. Phys. Chem. Chem. Phys. 1999, 1, 4151−4155. 63. Beyer, M.; Lammers, A.; Savchenko, E. V.; Schatteburg, G. N.; Bondybey, V. E. Proton Solvated by Noble−Gas Atoms: Simplest case of Solvated Ion. Phys. Chem. Chem. Phys. 1999, 1, 2213−2221. 64. Lignell, A.; Khriachtchev, L.; Lundell, J.; Tanskanen, H.; Räsänen, M. On Theoretical Predictions of Noble−Gas Hydrides. J. Chem. Phys. 2006, 125, 184514. 65. Grandinetti, F. Neon Behind the Signs. Nat. Chem. 2013, 5, 438.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

FIGURE CATIONS

Figure 1. Minimum Energy (C∞v Symmetry) and Transition State (Cs Symmetry) Structures of HNgCS+ Ions (Ng = He, Ne, Ar, Kr, and Xe). Figure 2. Minimum Energy Path for HNgCS+ Æ HCS+ + Ng Reaction (Ng = He , Ar, Kr, Xe) Calculated using DFT(B3LYP) method.


Page 20 of 30

Page 21 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 1.

Minimum Energy (C∞v Symmetry) and Transition State (Cs Symmetry)

Structures of HNgCS+ Ions (Ng = He, Ne, Ar, Kr, and Xe).



+ 0 HHeCS

50

-100 -200 Transition state of + HHeCS -300 (33 kJ/mol) -400 +

-500 He + HCS (~ -532 kJ/mol) -600 -3 -2 -1

0

1

2

3

4

5

6

7

Reaction Coordinate, bohr amu1/2

8

Relative Energy (kJ/mol)


0 HArCS+ -50 -100 -150

Transition state of + HArCS (29 kJ/mol)

-200 -250 -300

+

-350 -400

Ar + HCS (~ -388 kJ/mol)

-450 -6

-4

-2

0

2

4

6

8

10



50


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 30

0 HKrCS+ -50 -100 Transition state of + HKrCS (37 kJ/mol)

-150 -200 -250

+

-300

Kr + HCS (~ -339 kJ/mol)

-350 -6

-4

-2

0

2

4

6

8

0

+

HXeCS

-50 -100

Transition state of + HXeCS (37 kJ/mol)

-150 -200 -250

+

Xe + HCS (~ -285 kJ/mol)

-300 -6

10

-4

-2

0

2

4

6

8

10



Figure 2. Minimum Energy Path for HNgCS+ Æ HCS+ + Ng Reaction (Ng = He , Ar, Kr, Xe) Calculated using DFT(B3LYP) method.


Page 23 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48


Table 1. Optimized Structural Parametersa of HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe) Species, Calculated using MP2, DFT and CCSD(T) Methods. Geometrical Methods Parameters MP2 R(H-Ng) DFT CCSD(T) CCSD(T) (Previously Reported) R(Ng-C)

R(C-S) θ (H-Ng-C) θ (Ng-C-S)

MP2 DFT CCSD(T) CCSD(T) (Previously Reported) MP2 DFT CCSD(T) MP2 DFT CCSD(T) MP2 DFT CCSD(T)

HHeCS+ Minima TSb 0.760 0.753 0.810 0.769 0.766 0.741 0.776c 0.771d 0.764e 0.765f 2.038 2.268 1.960 2.274 2.036 2.270 2.240g 2.221h 2.138i 1.522 1.524 1.507 1.513 1.524 1.534 180 116.6 180 108.5 180 116.5 180 172.8 180 171.9 180 179.9

HNeCS+ Minima TSb 0.981 0.980 1.026 1.014 0.986 0.985 0.992c 0.967e 2.587 2.506 2.585

2.612 2.576 2.603

2.712h 1.528 1.515 1.532 180 180 180 180 180 180

1.528 1.516 1.532 150.3 136.8 153.0 177.2 175.7 177.6

HArCS+ Minima TSb 1.282 1.274 1.311 1.289 1.284 1.277 1.282c 1.286d 1.278d 1.281e 1.280f 2.705 3.079 2.663 3.104 2.725 3.068 3.318g 2.943g 2.911h 2.841i 1.526 1.530 1.513 1.520 1.530 1.534 180 108.2 180 106.0 180 108.3 180 176.7 180 176.5 180 176.7

23

ACS Paragon Plus Environment

HKrCS+ Minima TSb 1.423 1.411 1.453 1.427 1.425 1.413 1.416c 1.422d 1.413d 1.417e 1.416f 2.741 3.238 2.723 3.289 2.757 3.224 3.487g 2.980g 3.068h 2.922i 1.525 1.531 1.512 1.521 1.530 1.534 180 108.2 180 106.0 180 108.3 180 176.7 180 176.5 180 176.7

HXeCS+ Minima TSb 1.621 1.605 1.642 1.615 1.620 1.604 1.607c 1.620d 1.604d 1.610e 1.607f 2.882 3.476 2.901 3.540 2.872 3.453 3.730g 3.090g 3.124h 3.093i 1.525 1.532 1.513 1.523 1.528 1.536 180 102.2 180 101.6 180 101.2 180 178.1 180 178.0 180 178.6


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

a

Page 24 of 30

Bond length is in Å, and bond angle θ in degree; bTransition state; cThe CCSD(T) computed H−Ng bond lengths in bare HNg+ ions;

d

The

CCSD(T) computed H−Ng bond lengths in HNgBF+ ions;45 eThe CCSD(T) computed H−Ng bond lengths in HNgCO+ ions;42 fThe CCSD(T) computed H−Ng bond lengths in HNgN2+ ions;43 g The CCSD(T) calculated Ng−B bond lengths in HNgBF+ ions;45 h CCSD(T) calculated Ng−C bond lengths in HNgCO+ ions;42 i The CCSD(T) calculated Ng−N bond lengths in HNgN2+ ions.43

Table 2. Harmonic Vibrational Frequencies (in cm-1) and Intensitiesa Calculated using MP2, DFTb, and CCSD(T)c Methods for HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe) Ions for the Minima and the Transition States (TS). H-He-C-S+ Normal mode (symmetry) H-Ng stretch

C-S stretch

Minima

3398.6 (45.6) {2692.9} (509.1) [3270.1] 1359.6 (2.7) {1423.0} (3.9) [1375.8]

TS

3563.1 (796.3) {3336.0} (570.5) [3706.3] 1346.2 (0.04) {1394.3} (7.2) [1334.7]

H-Ne-C-S+

H-Ar-C-S+

H-Kr-C-S+

H-Xe-C-S+

Minima

TS

Minima

TS

Minima

TS

Minima

TS

3027.5 (649.2) {2275.9} (807.4) [3004.7] 1330.4 (6.5) {1379.2} (50.4) [1337.7]

3036.0 (719.7) {2449.7} (633.9) [3018.0] 1329.5 (6.6) {1375.8} (52.2) [1337.2]

2637.9 (156.9) {2384.3} (24.6) [2692.4] 1337.9 (1.1) {1390.6} (22.4) [1347.7]

2706.3 (541.9) {2611.7} (467.3) [2772.5] 1319.0 (8.9) {1359.0} (41.0) [1325.4]

2520.7 (58.3) {2282.0} (53.3) [2491.8] 1341.0 (0.1) {1394.3} (19.4) [1352.6]

2608.6 (399.0) {2476.8} (358.7) [2586.8] 1315.8 (10.1) {1354.0} (43.2) [1320.6]

2278.1 (24.0) {2120.4} (52.3) [2228.1] 1338.7 (0.003) {1389.3} (22.2) [1353.6]

2363.0 (229.5) {2266.0} (207.7) [2322.4] 1311.3 (11.9) {1347.3} (47.8) [1314.8]

24


Page 25 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48


122.4 103.8 134.7 120.4 153.1 166.7 167.6 375.5 (22.3) (23.6) (25.5) (30.7) (38.2) (63.8) (48.5) (272.4) {122.7} {99.9} {140.8} {115.4} {162.9} {176.6} {182.5} {373.9} (0.5) (19.9) (25.7) (31.0) (43.3) (67.7) (61.2) (268.5) [125.2] [98.9] [135.4] [120.3] [152.3] [173.4] [172.5] [362.9] −262.2 −287.4 −197.1 −690.2 412.4 436.2 418.6 159.4 H-Ng-C d (21.0) (56.2) (70.2) (92.5) (101.0) (335.7) (273.5) (94.8) bend {407.2} {460.0} {−261.4} {461.7} {−297.6} {−308.4} {−1072.1} {247.5} (20.5) (50.9) (63.7) (83.8) (87.3) (250.8) (203.9) (37.2) [−249.7] [−280.3] [−158.3] [−822.0] [410.7] [413.1] [389.9] [132.5] 124.6 92.7 128.6 109.9 131.4 130.0 131.5 171.4 Ng-C-S d (21.5) (7.3) (27.9) (19.6) (37.1) (64.7) (21.6) (112.3) bend {122.2} {87.1} {128.1} {105.7} {131.4} {127.4} {132.7} {167.8} (16.9) (7.2) (21.3) (15.1) (28.6) (43.5) (44.1) (97.1) [118.7] [92.4] [121.8] [100.9] [122.6] [121.8] [118.8] [111.8] 102.6 113.4 132.1 178.3 H-Ng-C-S (26.6) (33.5) (96.6) (179.3) torsion {99.6} {109.2} {128.1} {177.5} (22.0) (28.9) (83.2) (169.6) [97.7] [103.0] [123.7] [163.6] a Corresponding IR intensity values calculated using DFT and MP2 methods are given within the parentheses (in km mol-1). Ng-C stretch

b

416.7 (366.2) {462.4} (348.3) [411.7] 558.5 (153.9) {702.2} (120.6) [550.9] 183.4 (122.4) {186.7} (95.7) [177.4] -

The DFT calculated values are given within the curly brackets.

c

The CCSD(T) calculated values are given within the square brackets.

d

For minima the modes are doubly degenerate.

25


97.9 (18.1) {93.0} (14.7) [88.8] −228.9 (40.2) {−229.1} (40.8) [−223.3] 80.2 (4.8) {73.2} (4.9) [80.3] 97.2 (17.6) {91.7} (14.4) [87.4]


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Page 26 of 30

Table 3. MP2 and DFTa Calculated Values of the Harmonic Vibrational frequencies (in cm-1) and Intrinsic Force Constants in the Parentheses (in N m−1) Corresponding to Individual Internal Coordinates of HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe) Ions. Internal coordinate

HHeCS+

HNeCS+

HArCS+

HKrCS+

HXeCS+

H-Ng stretch

3398.9 (548.0)

3027.7 (518.1)

2638.5 (403.2)

2521.1 (372.9)

2278.3 (305.9)

[2692.7] (343.9)

[2277.8] (293.3)

[2385.3] (329.6)

[2282.5] (305.6)

[2120.7] (265.0)

1336.0 (917.6)

1319.0 (894.4)

1323.4 (900.4)

1325.5 (903.2)

1324.0 (901.1)

[1392.9] (997.4)

[1364.6] (957.2)

[1373.0] (969.0)

[1376.1] (973.5)

[1373.0] (969.0)

485.2 (41.6)

238.8 (25.2)

241.6 (31.8)

239.8 (35.7)

230.6 (34.4)

[547.5] (52.9)

[254.7] (28.6)

[265.7] (38.3)

[261.0] (42.2)

[243.0] (38.3)

556.0

159.4

416.0

432.9

408.1

[696.3]

[247.3]

[458.6]

[456.4]

[402.8]

190.8

131.4

139.6

139.1

137.8

[207.6]

[133.1]

[141.8]

[140.4]

[135.9]

C-S stretch Ng-C stretch H-Ng-C bend Ng-C-S bend a

The DFT calculated values are given within the square brackets.

26


Page 27 of 30


1 2 3 4 5 6 Table 4. Energies (in kJ mol-1) of the Various Dissociated Species Relative to the HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe) Ions, Calculated 7 8 Using MP2, DFT and CCSD(T) Methods. 9 10 Molecular Ng = He Ng = Ne Ng = Ar Ng = Kr Ng = Xe 11 Species 12 MP2 DFT CCSD(T) MP2 DFT CCSD(T) MP2 DFT CCSD(T) MP2 DFT CCSD(T) MP2 DFT CCSD(T) 13 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 HNgCS+ 14 15 + Ng + HCS −528.9 −497.0 −518.3 −548.9 −533.3 −530.6 −369.9 −352.0 −347.2 −302.6 −292.7 −266.9 −243.0 −234.8 −201.9 16 + 17 108.9 125.0 101.7 68.1 71.3 62.2 79.0 79.3 72.5 82.1 81.2 76.6 82.0 75.8 77.9 HNg + CS 18 142.6 106.0 75.8 122.7 69.8 63.3 301.6 251.2 246.4 368.9 310.4 326.3 428.5 368.4 390.9 HNg + CS+ 19 + 20 141.1 103.8 74.4 119.2 65.7 60.3 281.1 205.8 223.0 226.9 227.5 254.1 222.6 232.9 259.2 H + NgCS 21 + 142.7 106.1 75.8 122.7 69.8 63.5 301.7 251.2 246.9 369.0 310.4 327.2 428.6 368.4 392.1 22 H + Ng +CS 23 302.5 318.6 298.2 282.6 282.3 285.9 461.5 463.7 469.2 528.8 522.9 549.9 588.5 580.9 614.5 H+ + Ng + CS 24 a 25 Barrier Height 12.5 32.7 13.3 0.4 2.6 0.3 21.3 29.2 19.5 29.3 36.9 27.5 34.3 37.4 33.9 26 a Barrier height corresponding to transition state for the reaction HNgCS+ → HCS+ + Ng. 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 27 43 44 45 46 ACS Paragon Plus Environment 47 48


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Page 28 of 30

Table 5. MP2 and DFTa Calculated Values of the Partial Mulliken Charges in HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe) Ions Using 6−311++G(2d,2p) Basis Sets with Gamess Program and the Corresponding NBO Charges Using the Same Basis Sets with MOLPRO Program.

H-He-C-S+

Mulliken Atom

H-Ne-C-S+ NBO

H-Ar-C-S+

Mulliken

NBO

Mulliken

H-Kr-C-S+ NBO

Mulliken

H-Xe-C-S+ NBO

Mulliken

NBO

Min

TSb

Min

Min

TSb

Min

Min

TSb

Min

Min

TSb

Min

Min

TSb

Min

0.587

0.616

0.640

0.618

0.627

0.749

0.362

0.384

0.436

0.241

0.300

0.309

0.152

0.198

0.162

(0.541)

(0.626)

(0.536)

(0.563)

(0.590)

(0.695)

(0.348)

(0.393)

(0.418)

(0.229)

(0.304)

(0.298)

(0.160)

(0.211)

(0.180)

0.325

0.367

0.289

0.372

0.365

0.241

0.629

0.620

0.528

0.681

0.687

0.641

0.783

0.802

0.779

(0.267)

(0.350)

(0.267)

(0.358)

(0.347)

(0.226)

(0.593)

(0.603)

(0.498)

(0.647)

(0.683)

(0.610)

(0.727)

(0.785)

(0.731)

-0.147

-0.197

-0.460

-0.199

-0.208

-0.431

-0.120

-0.143

-0.444

-0.262

-0.259

-0.448

-0.039

-0.121

-0.449

(-0.023)

(-0.146)

(-0.297)

(-0.106)

(-0.125)

(-0.327)

(-0.042)

(-0.107)

(- 0.350)

(-0.171)

(-0.194)

(-0.356)

(0.035)

(-0.079)

(-0.311)

0.235

0.214

0.531

0.208

0.216

0.442

0.128

0.139

0.480

0.341

0.272

0.498

0.104

0.122

0.508

(0.215)

(0.171)

(0.494)

(0.186)

(0.189)

(0.407)

(0.101)

(0.111)

(0.434)

(0.295)

(0.208)

(0.448)

(0.078)

(0.083)

(0.400)

charge q(H)

q(Ng)

q(C)

q(S) a

The DFT calculated values are given in the parentheses.

b

Transition state

28


Page 29 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48


Table 6. Bond Critical Point Electron Density (ρ), Laplacian (∇2ρ), and the Local Electron Density (Ed) of HNgCS+ (Ng = He, Ne, Ar, Kr, and Xe) Ions Calculated Using the MP2 and DFTa Methods. H-He-C-S+

Bond

H-Ng

Ng-C

C-S

H-Ne- C-S+

H-Ar- C-S+

H-Kr- C-S+

ρ

∇2ρ

Ed

ρ

∇2ρ

Ed

ρ

∇2ρ

Ed

ρ

∇2ρ

Ed

ρ

∇2ρ

Ed

(ea0-3)

(ea0-5)

(au)

(ea0-3)

(ea0-5)

(au)

(ea0-3)

(ea0-5)

(au)

(ea0-3)

(ea0-5)

(au)

(ea0-3)

(ea0-5)

(au)

0.246

-2.724

-0.694

0.231

-2.739

-0.725

0.233

-0.898

-0.271

0.206

-0.599

-0.191

…

…

…

(0.227)

(-1.821)

(-0.478)

(0.209)

(-1.698)

(-0.467)

(0.220)

(-0.711)

(-0.220)

(0.194)

(-0.512)

(-0.165)

0.038

0.111

-0.002

0.017

0.070

0.002

0.025

0.079

0.001

0.028

0.081

0.001

0.027

0.068

-0.001

(0.047)

(0.111)

(-0.003)

(0.021)

(0.080)

(0.002)

(0.028)

(0.078)

(0.001)

(0.029)

(0.079)

(0.001)

(0.027)

(0.064)

(-0.001)

0.283

-0.228

-0.398

0.283

-0.293

-0.396

0.282

-0.282

-0.395

0.282

-0.280

-0.395

0.282

-0.283

-0.394

(0.291)

(-0.109)

(-0.406)

(0.290)

(-0.179)

(-0.403)

(0.291)

(-0.169)

(-0.404)

(0.291)

(-0.168)

(-0.404)

a

The DFT calculated values are given in the parentheses.

H-Xe- C-S+

29


(0.152) (-0.333)

(0.291) (-0.176)

(-0.123)

(-0.405)


Page 30 of 30

TOC Graphics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Ng = He, Ne, Ar, Kr, and Xe


Theoretical Prediction of Noble Gas Inserted Thioformyl Cations

Recommend Documents