Te•••π Double Chalcogen Bonding

Subscriber access provided by Miami University Libraries

Communication

Dispersion Stabilized Se/Te•••# Double Chalcogen Bonding Synthonsin insitu Cryocrystallized Divalent Organochalcogen Liq-uids Subhrajyoti Bhandary, Abhishek Sirohiwal, Rahul Kadu, Sangit Kumar, and Deepak Chopra Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.8b00585 • Publication Date (Web): 05 Jun 2018 Downloaded from http://pubs.acs.org on June 5, 2018

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 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 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.

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 7 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

Crystal Growth & Design

Dispersion Stabilized Se/Te···π Double Chalcogen Bonding Synthonsin insitu Cryocrystallized Divalent Organochalcogen Liquids Subhrajyoti Bhandary,aAbhishek Sirohiwal,a, b Rahul Kadu,aSangit Kumar,*a and Deepak Chopra*a a

Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal By-Pass Road, Bhopal, Madhya Pradesh, India-462066. b Present address: Max-Planck-InstitutfürKohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheiman der Ruhr, Germany. ABSTRACT:We report the experimental observation and detailed quantum chemical analysis of the rare bifurcated type Se···π and Te···π ‘double’ chalcogen bonded synthons observed through the in situcryocrystallization of two room temperature organochalcogen liquids, namely, diphenylselenide and diphenyl telluride. The attractive intermolecular interactions between the heavier chalcogens and π-clouds are primarily stabilized by the dispersion forces, which is in contrast to many known model examples in the literature. Electrostatic and orbital delocalization effects also play a secondary but inportant role in the overall stabilization, besides providing directionality to these interactions.

In the diverse areas of supramolecular chemistry, crystal engineering, material science, and molecular biology, the noncovalent interactions are the controlling factors that govern the events both at the molecular and the bulk levels. Indeed, the most fundamental classical noncovalent interaction is the hydrogen bond which has been well acknowledged for a long time.1In the last decade, the focus has been shifted towards the halogen bonding interactions owing to their potential applications in several branches of science to design materials possessing desired properties. 2-3Like the halogen bond, favourable interactions between the chalcogens (S, Se, and Te) with a Lewis base are known as the ‘chalcogen bond’, which has recently emerged as an equivalent and important noncovalent interaction. 4-7 It has been discovered that such interactions play a crucial role in synthesis8, organocatalysis and materials 9, structural biology 10, crystal engineering 11-14, pharmaceuticals drugs 12and self-assembly process 15. The characteristic of the chalcogen bond is similar to that of the halogen bond, which is an attractive interaction between the σ* of the Ch-X and the electron donor species. Hence, it can be categorized as a subclass of well-known ‘σhole interaction’.16-18Depending on the nature of substituents (X),the anisotropic distribution of the electron density on the chalcogen atom can be modulated, which results in the creation of a region with electropositive character (popularly known as ‘σ- hole’) opposite to the Ch-X covalent bond, which is responsible for the electrostatic interaction with the electron rich species.Other major contributors to the overall ‘σ- hole’ mediated stabilizations are the dispersion and the orbital mixing interactions. 2, 6, 17The electrostatic and orbital mixing interactions are only prevalent under specific geometric requirements; hence these are mainly responsible for the directional features of noncovalent interactions. The tunability and strength of the chalcogen bonds are significantly influenced by the nature of both the electron donor and the acceptor chalcogen atom. A lot of efforts have

been devoted in the last few years towards the understanding of the origin and strength of the chalcogen bonds for different molecules from both an experimental and computational perspective.19-27 Among them, the interactions involving heavier chalcogens (Se and Te) with the aromatic π-donor are not so common.28 On the other hand, halogen bonding is well characterized with a promising role as functional materials in donor-accepter π-systems.29 In a Cambridge Structural Database (CSD) study, Bauza and co-workers 30 have shown that the chalcogen atoms preferably interact with the lone pair of a donor atom rather than with the π-electron cloud of an aromatic ring. Althoughthe S···π (aromatic ring) chalcogen contacts have been found for a large number of compounds in a recent CSD survey,28, 31the Se···π (aromatic ring) contacts are rare,and Te···π (aromatic ring) bonding is extremely unusual (see Supporting Information for the details of CSD study).There are many diaryl based synthetic precursorswhich contain Se and Te.32-33 The interaction with the π-cloud could play a decisive in determining the chemical reactivity of the molecule of interest with implications in the biologically important small-molecule Se/Te containing drugs, which could interact with the residue with π-cloud based side chains(for example Phe, Tyr, etc.) Thus, a detailed investigation of the Se/Te···π interaction is required to decipher the role of various binding forces and recognize their supramolecular significance. Besides this, the aromatic-chalcogen compounds containing Se/ Te element have always received special attention due to soft metal-like behaviour

ACS Paragon Plus Environment

Crystal Growth & Design 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. Molecular structure of diphenyl selenide (Ph2Se) and diphenyl telluride (Ph2Te) with the atom-numbering scheme.

forSe and very low natural abundance of Te.34However, instability, higher lability and chemical sensitivity of such compounds makes the investigation of their supramolecular architectures challenging. This is mainly because of the significantly lower bond energy of Te-C (200 kJ/ mol) and Se-C (234 kJ/ mol) single bonds than that of S-C (272 kJ/ mol) bond. 34 As a part of our continuing investigation to probe molecular conformation and intermolecular interactions in in situ cryocrystallized liquids 35-37 we report herein the crystal structure of diphenylselenide (Ph2Se) and diphenyl telluride (Ph2Te). These compounds were freshly synthesizedin accordance withthe previously reported procedure.32 It is noteworthy that thestructure of diphenyl ether (Ph2O) has already been reported as dimorphs in the literature.38 The synthesized compounds exist as a yellow/orange liquid at room temperature, and their structures were successfully determined via the state-of-the-art in situ cryo-crystallization technique using optical heating and crystallization devices (OHCD) followed by the methodology described elsewhere (see Supporting Information).35 On the other hand, all the attempts toward the crystallization of diphenyl sulfide (Ph2S) were unsuccessful. The in situ cryo-crystallization of liquids provides improved prospects towards the understanding of the importance of secondary bonding interactions (such as halogen and chalcogen bonds) in the absence of classical hydrogen bonding interactions and the role of solvents during the process of molecular self-assembly. 4, 35-37 With this aim, the crystallization of two divalent Se and Te compounds (Ph2Se and Ph2Te) show that both liquid crystallizes in the same monoclinic non-centrosymmetric space group (P21, Z = 2) (Figures S1-S4 and Tables S1-S3). The crystal structures are also quite similar to each other in both cases, leading to the formation of a layered supramolecular architecture in the solid state. In Ph2Se, such layers are mainly stabilized by the formation of double (bifurcated type) chalcogen bonding interactions21in which the divalent Se atom simultaneously interacts with the two phenyl rings (π2···Se···π1) in a single motif as shown by two red circles in Figure 2a. The intermolecular distances between Se and the closest carbon atoms of each of the π2 and π1 electron clouds were observed to be 3.59 Å and 3.71 Å respectively (sum of vdW radii of Se and C atoms is 3.60 Å).39 In addition, weak C-H···π interactions and longrange stacking interactions also contribute to the overall crystal packing. Striking similarities were observed in the crystal packing of Ph2Te, where the bifurcated chalcogen bonding supramolecularsynthons40 were found to be conserved throughout, same as in Ph2Se (red circlesin Figure 2b).

Figure 2. Crystal packing of (a) Ph2Se and (b) Ph2Te showing the occurrence of double π2···Se···π1 and π2···Te···π1 chalcogen bonding synthons (red circles) respectively, connected via the CH···π interactions. Distance (Å) and angle (°) parameters for chalcogen bonds are showing in blue.

It isimportant to note that the π2···Te···π1 chalcogen contacts in Ph2Te are shorter (3.67 Å and 3.73 Å respectively) than the sum of the vdW radii of Te and C atoms (3.90 Å). The Se/Te···π interactions were found to be directional, owing to the electrostatic and orbital-overlapping effects, and their presence in quantitatively characterized in this work. Here, it is also important to mention that the previously reported supramolecular structures (dimorphs) of Ph2O were exclusively guided by the C-H···π interactions.38

Figure 3. Molecular graphs for two chalcogen bonding synthons depicting the bond critical points (BCPs; dark red dots) at intermolecular bifurcated double (a) Se···π1/ π2 and (b) Te···π1/ π2 bond paths. The ρ values of all four chalcogen···π BCPs are given in blue.The values of ρ (e/Å3), ∇2ρ (e/Å5) and ε of all four chalcogen···π BCPs are given in blue.

The topological features of a chalcogen bond are routinely explored with the Bader’s quantum theory of atoms in molecules (QTAIM).41-42 In the present case, the characteristic (3, -1) BCPs were found, with a significant amount of electron density (ρ) and positive values of Laplacian (∇2ρ), between each chalcogen atom (Se/ Te) with two π-rings concomitantly (Figure 3). These are sufficient indicators to label the Se/Te···π contacts as ‘closed-shell’ bonding interactions. Generally, the amount of electron density associated with BCP is a measure of bond-order, which is directly associated with the bond strength. It has been observed that the values of electron density and Laplacian for the two Se···π contacts are relatively less than those of two Te···π contacts (Figures 3a-b). Also, the ellipticity (ε) of bond-paths often indicates the type of interaction between the donor and acceptor species, for e.g.we observed an “inward-pointing” bond-path for both Se/Te···π interactions. Such curvatures in the bond-paths are often observed in the metal-alkene interactions due to the averaging of the synergic electron donation between metal and

ACS Paragon Plus Environment

Page 2 of 7

Page 3 of 7 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

Crystal Growth & Design alkene.37Similarly, the curved bond-path of Se/Te···π points towards some extent of electron donation from Se/Te to the πcloud, a detailed quantitative analysis is discussed in the upcoming section. However, in Ph2Se, we observed the presence of two additional BCP’s between non-directional C-H···π and long-range displaced π···π contacts. (Figure 3a) The electron density associated with the BCP’s of these interactions is low (Table S4); thus, these interactions are of only secondary importance to the overall crystal packing, in addition to the presence of the highly directional Se···π interaction. In general, lighter Group 16 congeners, involved in the formation of the chalcogen bond are primarily stabilized by the electrostatic σ-hole interaction. Depending on the chemical environment, the presence of dispersion and orbital mixing play a secondary, but important role, in the overall stabilization of Table 1. LMO-EDA interaction energies of dimers and their partitioned components (in kJ/ mol). Computed at M06-2X/cc-pVDZ-PP (Se/ Te) and 6-31G** (other atoms). Motif

Eelec

Eex-rep

Epol

Edisp

Etotal

Se···π

-12.79

40.67

-3.76

-38.46

-14.34

Te···π

-16.30

49.74

-5.10

-43.60

-15.26

Figure 4. Molecular electrostatic potentials of (a) Ph2Se and (b) Ph2Te computed with a scale of -52.5 (red) to 52.5 kJ/mol (blue). Arrows indicate the presence of σ-holes with their magnitudes (Vs, max) corresponding to the Se/ Te···π2 (left ring) and π1 (right ring) chalcogen bonding.

dominate in comparison to the electrostatic interaction (Table 1), and also the total interaction energy for the Se···π synthon (-14.34 kJ/ mol) is marginally lower than that of the Te···π (15.26 kJ/ mol) interaction.44 The contribution of dispersion interactions in the overall stabilization of the Se and Te based dimer is nearly the same, i.e. 70% and 67%, respectively. Similar trends were observed in the stabilization from the electrostatic counterpart for Se···π (23%) and Te···π (25%), it becomes obvious that the source of such evident electrostatic contribution must be from the σ- hole generation on the Se and Te. It is also clear that the electrostatic interactions only play a secondary role in the overall stabilization. However, a recent investigation 45depicts the prevalence of σ-holes of greater magnitude, on both Se and Te atoms in (C6F5)2-Se/Te type of complexes, which are known to be important for noncovalent catalysis. The -Ph group in the current study, which is less electron-withdrawing compared toC6F5, is also capable of forming a σ-hole on chalcogens (arrows in Figure 4). The molecular electrostatic potential (MESP) surfaces of the compounds Ph2Se and Ph2Te clearly show the presence of two electropositive regions (dark blue) on each Se and Te atom, opposite to the individual Se/Te-C single bonds. These positive regions are the characteristics of σ-holes on the chalcogen atoms, which interact with the negative MESP surface on the two π-aromatic rings (red regions) functioning as an electron donor, individually corresponding to the presence of two Se···π2/ π1 and Te···π2/ π1 chalcogen bonds (Figure 4).This observation might be helpful to recognize the origin of the electrostatic contribution term in the EDA analysis. In addition to this, the magnitude of maximum positive ESP (Vs, max) associated with two σ-holes on the Te atom (94.5 and 91.9 kJ/mol) was found to be compared to the Se atom (60.4 and 55.1 kJ/mol).This is on account of the greater polarizability and smaller electronegativity of the Te atom than that of the Se atom. Interestingly, the magnitudes of the two σ-holes on individual Te and Se, respectively, were also observedto be little asymmetric. The consequences of this electrostatic asymmetry are very well reflected in the geometrical preferences of Se/Te···π interaction, for e.g. the π2 forms highly directional interaction (166° for C-Se···π2 and 171° for C-Te···π2) with the σ- hole of greater positive potential of Se/Te, whereas, the interaction of such chalcogens with the π1 is not directional to a similar extent (154° for CSe···π1 and 152° for C-Te···π1). Such directional preferences with the π-cloud are often required for the efficient orbitalmixing or charge-transfer effects.In order to rationalize the role of orbital-mixing effects in Ph2Se and Ph2Te, we have performed the Natural Bond Orbital (NBO) analysis.42Theobtained results point towards the minimal role of charge-transfer effects on the overall stabilization of the two compounds under investigation (Figure 5).For e.g., compound Ph2Se exhibits the overlap between the two σ* (Se-C)

suchsynthons. To quantitatively measure these contributions, we have employed an energy decomposition analysis (EDA)using the LMO-EDA approach implemented in the GAMESS program package.43 This method provides the breakdown of the total interaction energy of a dimer into the electrostatic, exchange-repulsion, polarization, and the dispersion energy. Calculations performed on the respective dimers of these compounds depicts the opposite trend, wherein the total stabilization from the dispersion interaction was found to

ACS Paragon Plus Environment

Crystal Growth & Design 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

based on the magnitude of ρ*sign (λ2), where electron density (ρ) determines the strength of interaction, whereas, the sign (λ2) distinguishes between the attractive (λ2< 0) and repulsive (λ2> 0) interactions. The mapping of the quantity ρ*sign (λ2) onto the RDG isosurface provides chemical insights on the nature and strength of noncovalent interactions. The chalcogen bonding in Ph2Se and Ph2Te are clearly manifested by the two individual disk-like isosurfaces between the closely interacting Se/Te with the two aromatic rings (Figures 6a-b).The space between Se/Te and π-clouds is mainly dominated by the low electron density region with a negative λ2, which are clearly the characteristics of dispersion forces bound interactions. It is, as

Figure 5. Relevant NBO orbitals are showing the charge transfer from bonding π orbitals of aromatic ring to σ* of Se-C (a1 and a2) and Te-C (b1 and b2) single bonds in Se···π and Te···π synthons respectively. Red and blue lobes show opposite sign of each wave function.

antibonding orbitals with the occupied π orbitals of the two phenyl rings (π1/ π2).The energetic consequences of charge transfer from π1
σ* (Se-C7) and π2
σ* (Se-C1) are 2.2 and 3.0 kJ/ mol respectively as obtained from their second-order perturbation energies (Figures 5a1-a2), while almost negligible back donation from the lone pairs of divalent Se to the π* orbitals of the aromatic ring was observed.Interestingly, recent results from Steiner and co-workers 23 demonstrated a significant back-donation from a di-valent sulfur lone pair to the π* of the C=C bond.In case ofPh2Te, the charge transfer effects from orbital interactions between π1
σ* (Te-C7) and π2
σ* (Te-C1) are 3.5 and 0.8 kJ/ mol, respectively(Figures 5b1-b2).It is clear now that the net stabilization from π
σ* charge transfer is slightly greater in case of Ph2Se compared to that of Ph2Te, however, an additional stabilization for the Te···π chalcogen bond is observed due to the back-charge transfer (corresponding to a total of 2.2 kJ/mol) from the lone pairs of Te to the π* antibonding orbitals of the aromatic rings (Table S5).It can be summarized that the charge transfer effects do exist in these class of synthons, but are not as prominent as the other counterpart, namely the dispersion and the electrostatic contributions. It is clear until now that, the dispersion and electrostatic interactions are two major components for overall stabilization, with former dominant than the latter. The EDA scheme provides only the interaction energy of the overall dimer; thus, it would be an outrageous exercise to comment confidently on the “local nature” of the Se/Te and π interaction. Thus, the nature of the interaction in the locally confined real-space between the Se/Te atom and the π cloud is of prime importance. The noncovalent interaction descriptor (NCI) on the low-value isosurfaces of the reduced electron density gradient (RDG) is a powerful approach for the characterization of the various types of interactions within the real space visualization.46 The machinery of the NCI-RDG analysis is

Figure 6. RDG isosurfaces (the isovalue is 0.6 coloured over the range of -0.02 < ρ*signλ2 < 0.02 au.) correspond to the double (a) Se···π and (b) Te···π interactions.

Figure 7. Energy frameworks of (a) Ph2Se and (b) Ph2Te down the ac-crystallographic plane for the total interaction energy (blue) along with electrostatic (red) and dispersion (green) components. Yellow arrows show Chalcogen···π interactions.

of now, well-established here that the Se···π and Te···π synthons are stabilized primarily via the dispersion forces. The next and the final analysis is to have a complete picture of all the forces involved in the stabilization of the solid-state geometry of these molecules via an analysis of the energy frameworks.47 The framework of the interaction topology depicts a graphical representation of the partitioned electrostatic and dispersion contributions towards the total stabilization energy of the corresponding molecular pair in thesolid state.48The strength of the total interaction energy along with the breakdown components are visualized by the cylinders of different coloursand the cylinder radius is proportional to the relative magnitude of the interaction energy. In the case of Ph2Se, the vertical columns of cylinders represent the Se···π interactions (-20.9 kJ/ mol; yellow arrow in Figure 7a), which

ACS Paragon Plus Environment

Page 4 of 7

Page 5 of 7 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

Crystal Growth & Design has a larger radius than the horizontal columns corresponding to C-H···π interactions (-10.4 and -9.2 kJ/mol) as observed in the crystal packing. Now, the separate energy frameworks for electrostatic (red) and dispersive contributions (green) clearly shows that the cylinder representing the Se···π interaction has a smaller diameter for electrostatic interaction in comparison to that of the dispersive counterpart (yellow arrows in Figures 7a'-a''). This observation signifies that the dispersion interaction dominates over the electrostatic stabilization for Se···π chalcogen bond. Furthermore, similar energy frameworks for Te···π chalcogen bond also reveals the greater dominance of the dispersion stabilization over the electrostatic component towards the total interaction energy (-22.8 kJ/ mol) for the Te···π motif (Figures 7b and S5). In summary, the divalent chalcogenides reported here are capable of forming two directional secondary bonding interactions utilizing its two σ-holes on the chalcogen atom in a bifurcated fashion. In particular, the interaction between Se/Te and the π-cloud is stabilized by the dispersion forces, whereas the σ-hole mainly influences the directionality. To the best of our knowledge, the occurrence of these double chalcogen bonding Se···π and Te···π supramolecularsynthons are extremely unusual in crystal engineering and supramolecular science. We believe the exploitation of such chalcogen bonding synthons can be insightful in future for anion recognition process, organocatalysis, crystal engineering and development of pharmaceutical drugs.

ASSOCIATED CONTENT Supporting Information Details of in situ crystal growth, Description of single crystal data collection and structure solution, refinement, ORTEPs, packing diagrams, and Computational details are also providedin the Supporting Information.

Accession Codes CCDC. 1823314-1823315contain the supplementary crystallographic data for this paper.

AUTHOR INFORMATION Corresponding Author

Email: [email protected]; [email protected]: +91-0755-6692392. Notes The authors declare no competing financial interest.

ACKNOWLEDGMENTS We acknowledge IISER Bhopal for research facilities and infrastructure. S. B. thanks IISER Bhopal for the senior research fellowship. We would also like to thank Prof. Mark Spackman for helpful discussion regarding the energy framework calculations.

REFERENCES (1) Desiraju, G. R.; T. Steiner, The Weak Hydrogen Bond in Structural Chemistry and Biology, OUP, Oxford, 1999. (2)Gilday,L. C.; Robinson,S. W.;Barendt,T. A.; Langton,M. J.;Mullaney,B. R.; Beer,P. D. Halogen Bonding in Supramolecular Chemistry. Chem. Rev. 2015, 115, 7118. (3)Cavallo,G.;Metrangolo,P.;Milani,R.;Pilati,T.;Priim-gi, A.;Resnati,G.;Terraneo,G. The Halogen Bond. Chem. Rev. 2016, 116, 2478.

(4) Thomas,S. P.;Sathishkumar,R.; Guru Row,T. N. Organic alloys of room temperature liquids thiophenol and selenophenol. Chem. Commun. 2015, 51, 14255. (5) Kremer,A.; Fermi,A.;Biot,N.;Wouters,J.;Bonifazi,D. Supramolecular Wiring of Benzo‐1,3‐chalcogenazoles through Programmed Chalcogen Bonding Interactions. Chem. Eur. J.2016, 22, 5665. (6) Pascoe,D. J.; Ling,K. B.;Cockroft,S. L. The Origin of ChalcogenBonding Interactions. J. Am. Chem. Soc. 2017, 139, 15160. (7) Brammer,L.Halogen bonding, chalcogen bonding, pnictogen bonding, tetrel bonding: origins, current status and discussion.Faraday Discuss. 2017, 203, 485. (8) Benz,S.;Mareda,J.;Besnard,C.; Sakai,N.;Matile,S. Catalysis with chalcogen bonds: neutral benzodiselenazole scaffolds with highprecision selenium donors of variable strength. Chem. Sci.2017, 8, 8164. (9)Mahmudov,K. T.;Kopylovich,M. N.;Guedes da Silva,M. F. C.;Pombeiro,A. J. L. Chalcogen bonding in synthesis, catalysis and design of materials. Dalton Trans. 2017, 46, 10121. (10) Fick,R. J.; Kroner,G. M.; Nepal,B.;Magnani,R.; Horowitz,S.;Houtz,R. L.;Scheiner,S.;Trievel,R. C. Sulfur–Oxygen Chalcogen Bonding Mediates AdoMet Recognition in the Lysine Methyltransferase SET7/9. ACS Chem. Biol. 2016, 11, 748. (11) Bai, M.; Thomas, S. P.; Kottokkaran, R.; Nayak, S. K.; Ramamurthy, P. C.; Guru Row, T. N. A Donor–Acceptor–Donor Structured Organic Conductor with S···S Chalcogen Bonding. Cryst. Growth Des. 2014, 14, 459. (12) Thomas,S. P.;Satheeshkumar,K.;Mugesh,G.; Guru Row, T. N. Unusually Short Chalcogen Bonds Involving Organoselenium: Insights into the Se–N Bond Cleavage Mechanism of the Antioxidant Ebselen and Analogues. Chem. Eur. J. 2015, 21, 6793. (13) Brezgunova,M. E.;Lieffrig,J.;Aubert,E.;Dahaoui,S.;Fertey,P.;Lebegue,S.;Angyan,J. G.;Fourmigue,M.; Espinosa,E. Chalcogen Bonding: Experimental and Theoretical Determinations from Electron Density Analysis. Geometrical Preferences Driven by Electrophilic–Nucleophilic Interactions. Cryst. Growth Des. 2013, 13, 3283. (14) Huynh,H. T.;Jeannin,O.;Fourmigue,M. Organic selenocyanates as strong and directional chalcogen bond donors for crystal engineering. Chem. Commun. 2017, 53, 8467. (15) Ho,P. C.;Szydlowski,P.; Sinclair,J.; P. Elder,J. W.;Kubel,J.;Gendy,C.; Lee,L. M.; Jenkins,H.; Britten,J. F.;Morim, D. R.; Vargas-Baca,I. Supramolecularmacrocycles reversibly assembled by Te…O chalcogen bonding. Nat. Commun. 2016, 7, 11299. (16) Murray, J. S.; Lane, P.; Politzer, P. Expansion of the sigma-hole concept.J. Mol. Model. 2009, 15, 723. (17) Politzer, P.; Murray,J. S.; Clark,T. Halogen bonding and other σhole interactions: a perspective.Phys. Chem. Chem. Phys. 2013, 15, 11178. (18)Politzer,P.; Murray,J. S.; Clark,T. Mathematical modeling and physical reality in noncovalent interactions.J. Mol. Model. 2015, 21, 52. (19) Cozzolino,A. F.; Elder,P. J. W.; Vargas-Baca,I. A survey of tellurium-centered secondary-bonding supramolecularsynthons. Coord. Chem. Rev. 2011, 255, 1426. (20) Bora,P. L.;Novk,M.; Novotny´,J.;Foroutan-Nejad,C.;Marek,R. Supramolecular Covalence in Bifurcated Chalcogen Bonding. Chem. Eur. J.2017, 23, 7315. (21) Biot,N.;Bonifazi,D. Programming Recognition Arrays through Double Chalcogen- Bonding Interactions. Chem. Eur. J. 2017, 23, 1. (22)Bleiholder,C.; Werz,D. B.; Ko¨ppel,H.; Gleiter,R. Theoretical Investigations on Chalcogen−Chalcogen Interactions: What Makes These Nonbonded Interactions Bonding?. J. Am. Chem. Soc. 2006, 128, 2666. (23) Nziko,V. P. N.; Scheiner,S. J. Phys. Chem. A2015, 119, 5889. (24) Shukla,R.; Chopra,D. Exploring the Role of Substitution on the Formation of Se···O/N Noncovalent Bonds. J. Phys. Chem. B2015, 119, 14857. (25) Shukla, R.; Chopra, D. “Pnicogen bonds” or “chalcogen bonds”: exploiting the effect of substitution on the formation of P⋯Senoncovalent bonds. Phys. Chem. Chem. Phys. 2016, 18, 13820.

ACS Paragon Plus Environment

Crystal Growth & Design 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

(26) Esrafili, M. D.; Mohammadian-Sabet, F. Bifurcated chalcogen bonds: A theoretical study on the structure, strength and bonding properties. Chem. Phys. Lett. 2015, 634, 210. (27) Guo, X.; An, X.; Li, Q. Se···N Chalcogen Bond and Se···X Halogen Bond Involving F2C═Se: Influence of Hybridization, Substitution, and Cooperativity. J. Phys. Chem. A2015, 119, 3518. (28) Sedlak,R.; Eyrilmez,S. M.; Hobza,P.; Nachtigallova, D.The role of the σ-holes in stability of non-bonded chalcogenide⋯benzene interactions: the ground and excited states. Phys. Chem. Chem. Phys. 2018, 20, 299. (29) Zhu,W.; Zheng,R.; Zhen,Y.; Yu,Z.; Dong,H.; Fu,H.; Shi,Q.; Hu,W. Rational Design of Charge-Transfer Interactions in HalogenBonded Co-crystals toward Versatile Solid-State Optoelectronics. J. Am. Chem. Soc. 2015, 137, 11038. (30)Bauza´,A.;Quinonero,D.;Deya,P. M.;Frontera,A. Halogen bonding versus chalcogen and pnicogen bonding: a combined Cambridge structural database and theoretical study. CrystEngComm2013, 15, 3137. (31) Groom, C. R.; Bruno, I. J.; Lightfoot, M. P.; Ward, S. C.The Cambridge Structural Database.ActaCrystallogr. Sect. B: Struct. Sci. Cryst. Eng. Mater.2016, 72, 171. (32) Kumar,A.; Kumar,S. A convenient and efficient coppercatalyzed synthesis of unsymmetrical and symmetrical diarylchalcogenides from arylboronic acids in ethanol at room temperature. Tetrahedron2014, 70, 1763. (33) Stein,A. L.;Bilheri,F. N.; Zeni,G. Application of organoselenides in the Suzuki, Negishi, Sonogashira and Kumada cross-coupling reactions. Chem. Commun. 2015, 51, 15522. (34)Chivers,T.;Laitinen,R. S. Tellurium: a maverick among the chalcogens. Chem. Soc. Rev. 2015, 44, 1725. (35) Dey, D.; Bhandary, S.; Sirohiwal, A.; Hathwar, V. R.; Chopra,D. “Conformational lock” via unusual intramolecular C–F⋯O=C and C– H⋯Cl–C parallel dipoles observed in in situcryocrystallized liquids. Chem. Commun. 2016, 52, 7225-7228. (36) Dey, D.; Bhandary, S.; Thomas, S. P.; Spackman, M. A.; Chopra, D. Energy frameworks and a topological analysis of the supramolecular features in in situcryocrystallized liquids: tuning the weak interaction landscape via fluorination. Phys. Chem. Chem. Phys. 2016, 18, 31811-31820. (37)Sirohiwal,A.;Hathwar,V.;Dey,D.; Chopra,D. Investigation of Chemical Bonding in In Situ Cryocrystallized Organometallic Liquids. ChemPhysChem2017, 18, 2859.

(38) Choudhury,A. R.; Slam,K. I.; Kirchner,M. T.; Mehta,G.; Guru Row, T. N. In Situ Cryocrystallization of Diphenyl Ether: C−H···π Mediated Polymorphic Forms. J. Am. Chem. Soc. 2004, 126, 12274. (39)Bondi,A. van der Waals Volumes and Radii. J. Phys. Chem. 1964, 68, 441. (40)Desiraju,G. R. SupramolecularSynthons in Crystal Engineering— A New Organic Synthesis. Angew. Chem. Int. Ed. 1995, 34, 2311. (41) R. F. W. Bader, Atoms in Molecules: A Quantum Theory, Oxford University Press, Oxford, U.K., 1990. (42) All computational calculations for this paper were performed in Gaussian 09 using MP2/aug-cc-pVDZ-PP (for Se/ Te) and 6-311G ** (for C and H) mixed basis set (unless stated otherwise). For details and references, seeSupporting Information. (43) Su,P. F.; Li,H. Energy decomposition analysis of covalent bonds and intermolecular interactions.J. Chem. Phys. 2009, 131, 014102. (44) Interaction energies for Se···π and Te···π dimers were observed to be -18.85 kJ/mol and -20.52 kJ/mol respectively (BSSE corrected) as calculated in Gaussian 09 using MO6-2X/aug-cc-pVTZ-PP (for Se/ Te) and 6-311G ** (for C and H) level of theory. The relative energy difference remains consistent with the LMO-EDA results. (45) Benz,S.;Poblador-Bahamonde,A. I.; Low-Ders,N.;Matile,S. Catalysis with Pnictogen, Chalcogen, and Halogen Bonds. Angew. Chem. Int. Ed. 2018, 57, 1. (46) Saleh, G.; Presti, L. L.; Gatti, C.; Ceresoli, D. NCImilano: an electron-density-based code for the study of noncovalent interactions. J. Appl. Cryst. 2013, 46, 1513. (47) Mackenzie,C.F.;Spackman,P.R.;Jayatilaka,D.;Spackman,M.A. CrystalExplorer model energies and energy frameworks: extension to metal coordination compounds, organic salts, solvates and open-shell systems. IUCrJ2017, 4,575. (48) Turner, M. J.; McKinnon, J. J.; Wolff, S. K.; Grimwood, D. J.; Spackman, P. R.; Jayatilaka, D.; Spackman, M. A. CrystalExplorer17, 2017. University of Western Australia. http://hirshfeldsurface.net.

ACS Paragon Plus Environment

Page 6 of 7

Page 7 of 7 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

Crystal Growth & Design

For Table of Contents Use Only

Dispersion Stabilized Se/Te···π Double Chalcogen Bonding Synthonsin insitu Cryocrystallized Divalent Organochalcogen Liquids Subhrajyoti Bhandary,aAbhishek Sirohiwal,a, b Rahul Kadu,aSangit Kumar,*a and Deepak Chopra*a

Synopsis:The occurrence of rare bifurcated type dispersion stabilized Se···π andTe···π double chalcogen bonds were recognized in

the solid-state of two divalent organochalcogen liquids.

ACS Paragon Plus Environment

7