Interplay between Structural and Dielectric Features of New Low k

Article pubs.acs.org/crystal

Interplay between Structural and Dielectric Features of New Low k Hybrid Organic−Organometallic Supramolecular Ribbons Published as part of the Crystal Growth & Design virtual special issue on Halogen Bonding in Crystal Engineering: Fundamentals and Applications Paolo Sgarbossa,*,† Roberta Bertani,† Vito Di Noto,‡ Matteo Piga,‡ Guinevere A. Giffin,‡ Giancarlo Terraneo,§,# Tullio Pilati,§ Pierangelo Metrangolo,§,# and Giuseppe Resnati§,# †

Department of Chemical Processes of Engineering, University of Padova, via F. Marzolo, 9, I- 35132 Padova, Italy Department of Chemical Sciences, University of Padova, via F. Marzolo, 1, I- 35132 Padova, Italy § NFMLab, Department of Chemistry, Materials, and Industrial Chemistry “Giulio Natta”, Politecnico di Milano, Via L. Mancinelli 7, 20131 Milan, Italy # Italian Institute of Technology, Centre for Nano Science and Technology (CNST-IIT@PoliMi), Via Pascoli 70/3, 20133 Milan, Italy ‡

S Supporting Information *

ABSTRACT: The synthesis and characterization of low k one-dimensional (1D) hybrid organic−organometallic supramolecular ribbons 3a,b, through halogen-bond driven co-crystallization of trans-[Pt(PCy3)2(CC-4-py)2] (1) with 1,4-diiodotetrafluorobenzene (2a) and trans-1,2-bis-(2,3,5,6-tetrafluoro-4-iodophenyl)-ethylene (2b), are reported. The co-crystals 3a,b have been obtained by isothermal evaporation of a chloroform solution containing the corresponding starting materials at room temperature. X-ray structure determinations show that noncovalent interactions other than halogen bonds help in the construction of the crystal packing; these interactions are stronger in 3b, thus reducing the chain mobility with respect to 3a. Accordingly, the broadband dielectric spectroscopic determinations, carried out from 10−2 to 107 Hz and at a temperature ranging from 25 to 155 °C, showed that both 3a and 3b materials exhibit a real component of dielectric permittivity (ε′) significantly lower than SiO2. In particular in the case of 3b, the rigidity of the 1D chain explains the observed ε″ and tan δ values. A permittivity value that is significantly lower than that of the silica reference, tan δ values lower than 0.02 in the entire investigated temperature range, and less than 0.004 at T < 100 °C make 3b a very promising low k hybrid organic− organometallic material for application as dielectric films in next generation microelectronics.

1. INTRODUCTION Organometallic complexes are promising building blocks for the construction of self-assembled nanoscale materials.1 The self-assembly approach has engendered considerable attention in material science thanks to its ability to give rise to specific arrays and architectures as potential components for nanoscopic devices upon rational design.2 In crystal engineering,3 the interactions more frequently used are hydrogen bond (HB),4 halogen bond (XB),5 π−π stacking,6 van der Waals forces, electrostatic and donor−acceptor interactions,7 and coordinating bonds.8 The use of modules containing metal centers in supramolecular self-assembling9 is of particular interest because metal ions (in charged or neutral coordination compounds) provide redox, magnetic, optical, and reactive properties that are not usually available in carbon-based networks. The combination of polymer chemistry with supramolecular chemistry and coordination chemistry results in a class of new materials based on directional interactions and recognition processes at the molecular level. © 2011 American Chemical Society

Dielectric low k materials based on hybrid inorganic−organic materials are key systems yielding a new class of molecular micro-/nanocomponents for micro-/nanoelectronic devices, such as capacitors and field effect transistors (FET).10 To obtain advanced microelectronic devices, microcapacitors based on dielectric materials must be characterized by capacity values that are constant, independent of a decreasing electrode surface, and lower than 40 fF.11 In addition, as the size of devices on chips decreases, the distances between the interconnecting lines also decrease, and inductive and capacitive interferences between microcomponents increase. These phenomena originate in the so-called “inductive cross-talk”,11 which consists of a signal delay in the device, and are no longer modulated by the intrinsic gate delay of the FET but by the capacitive resistance of the interconnect array. The latter effect,11 is quantified by: τ = RC = 2ρεε0[4L2/P2 + L2/T2], where τ is a signal delay time, R Received: August 17, 2011 Revised: November 17, 2011 Published: November 18, 2011 297

dx.doi.org/10.1021/cg201073m | Cryst. Growth Des. 2012, 12, 297−305

Crystal Growth & Design

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Scheme 1. Synthesis of Supramolecular Ribbons 3a,b

is a resistance, C is a capacitance, ρ is the specific resistance of the conductor, ε is the dielectric constant of the insulating material, ε0 is the dielectric constant of vacuum, L is the length of the conductor, T is the thickness of the conductor, and P is the distance between two conducting lines. This equation clearly indicates that as the size of the electric microcomponent decreases, the signal delay time is expected to depend on the material’s dielectric constant when the resistance of the interconnect metal is constant. On the basis of the considerations summarized above,11,12 a compound acts as a successful dielectric material in a micro- or nanoelectronic device when it exhibits at least the following characteristics: (a) a dielectric constant 2σ(Io)] 6235 no. parameters 304 no. restraints 0 Rall 0.0477 Robs 0.0288 wRall 0.0691 wRobs 0.0630 goodness-of-fit on F2 1.030 Δρmin,max [e Å−3] −0.709; 0.898 CCDC 837212

14.014(2) 14.131(2) 17.040(3) 112.994(11) 98.072(9) 93.590(9) 3049.9(8) 1.673 2 0.08 × 0.14 × 0.16 3.431 0.6320, 0.7463 1520 pale yellow block 31.88 63535 20367 0.0275 17682 1016 2248 0.0341 0.0257 0.0619 0.0587 1.022 −1.419, 1.572 837213

3. RESULTS AND DISCUSSION Synthesis and Description of the Structures. Cocrystals 3a,b have been prepared as sketched in Scheme 1. Co-crystal 3a. The co-crystal 3a was obtained upon slow and isothermal evaporation at room temperature of a chloroform solution containing the trans-[Pt(PCy3)2(CC-4py)2] compound 1 and the diiodotetrafluorobenzene 2a in a 1:1 ratio. Visual thermal analysis performed on selected single crystal of 3a showed a slow and continuous modification of the

Co‐crystal 3a: m.p. = 263 °C (decomposition) Co‐crystal 3b: m.p. = 235 °C (decomposition) Crystallographic Data Collection and Structural Determination. The data collection of 3a and 3b single crystals was performed with a Bruker KAPPA APEX II with CCDC area detector diffractometer using graphite-monochromated Mo Kα radiation (λ = 299



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Figure 1. Top: Halogen bonded infinite chain of 3a. Bottom: Crystal packing of 3a, view along the a axis. Ellipsoid style with probability level at 50% by using Mercury 2.4. Halogen bonds are black dotted lines. Color code: gray, carbon; yellow-green, fluorine; blue, nitrogen; pink: platinum; dark yellow: phosphorus; purple, iodine. Hydrogen atoms are omitted for clarity.

Figure 2. Left: Quasi-orthogonal halogen bonded chains in 3a. Right: Halogen-bonded tapes in 3a, view along the b axis. Space filling style is used for metal-π-perfluorinated XB tapes and wireframe is used for the tricyclohexylphosphine groups. Color code as in Figure 1. Hydrogen atoms are omitted for clarity.

crystal between 150 and 240 °C, and then at 263 °C the decomposition of 3a was observed. The differential scanning calorimetry (DSC) thermogram confirmed the behavior detected during the visual studies. The different melting point of 3a, as compared to the starting materials (1 melts at 308.7 °C, and 2a melts at 108−110 °C), is consistent with the expected formation of a new crystalline species, rather than a mechanical mixture of the starting compounds. Single crystal X-ray diffraction analysis of 3a showed that the platinum derivative 1 and the diiodinated module 2a were present in a 1:1 ratio. The Pt adopted a square planar geometry with the two tricyclohexylphosphine groups and two alkynylpyridine moieties in trans position. As expected, the N···I halogen bonds are largely responsible for the self-assembly of the complementary modules 1 and 2a to give co-crystal 3a. Geometrical parameters of the halogen-bonded complex 3a are as follows: the N···I distance is 2.698(3) Å, which corresponds to a reduction of 23% of the sum of the van der Waals radii of nitrogen and iodine atoms and the N···I−C angle is 177.6(1)°.

These data are perfectly consistent with the occurrence of strong and directional halogen bonds. Notably the distance between the XB donor and acceptor atoms is extremely short, the second shortest distance ever observed in halogen bonded complexes involving diiodiotetrafluorobenzene as the building block (Search performed on Cambridge Structural Database (Version 5.32)).5e This feature may be related to the presence of a metallic center which imposes a rigid preorganized geometry on the XB acceptor reducing its degree of freedom and, in this way, increasing the interaction between the connecting units. The topology of the network formed by the self-assembly of 1 and 2a is a nice example of the paradigm of the expansion of ditopic starting modules; in fact, the halogen bond leads to the construction of the supramolecular 1D infinite chains formed by alternating XB donors and acceptors (Figure 1) where the conjugated metal-π-perfluorinated repeating unit, namely, Pt−CC-py···IC6F4I, spreads along the supramolecular organometallic copolymer. 300



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Figure 3. Top: Halogen-bonded infinity chain of 3b. Halogen bond interaction are highlighted with black dotted lines. Bottom: Repeating unit with tilted XB acceptors. Color code as in Figure 1. Hydrogen atoms are omitted for clarity.

Figure 4. Segregation between organometallic hydrocarbon and perfluorocarbon compounds in 3b. Halogen bond and C−F···π interactions are highlighted with black dotted lines. Color code as in Figure 1. Hydrogen atoms are omitted for clarity.

on the bulk material confirmed the same behavior suggesting that the sample was homogeneous and proving the formation of a new unique entity. Single crystal studies showed the presence of three molecules in the asymmetric unit of 3b, one molecule of the ligand 1 and two molecules of diiodo-octafluoro trans-stilbene 2b. The Pt center in this system also assumed the expected square planar geometry with two tricyclohexylphosphine groups and two alkynylpyridine moieties in trans position. Contrary to 3a, the two pyridyl moieties do not lay in the same plane but are tilted forming an angle of 79.77°. The two nitrogen atoms are halogen bonded to the electron-deficient iodine atoms forming, as in 3a, an alternating XB donor/acceptor 1D infinite chain (Figure 3). The N1···I2 and N2···I1 distances are 2.724(3) and 2.783(3) Å, while the C−I2···N1 and C−I1···N2 angles are 175.62(8) and 169.58(8)°, respectively. These contact distances are consistent with XBs already described for similar compounds.5a Interestingly, the iodotetrafluorobenzene rings are also tilted with respect to the halogen bonded pyridyl moieties. The angle between two consecutive XB acceptors is 46.40°. As in 3a, noncovalent interactions other than XB help the construction of the crystal packing of 3b. Weak hydrogen bonds between the methylene hydrogens on cyclohexyl and pyridyl rings are formed with the fluorine atoms. Further contacts involving the electron-deficient perfluorinated ring with neighboring hydrogens and fluorine atoms complete the stabilizing effect in the crystal lattice. In 3b the segregation between the fluorinated moiety and the hydrocarbon system is clear. Figure 4 shows the formation of a supramolecular ladder

The parallel metal-π-perfluorinated chains are organized in planes orthogonal to c* where the tricyclohexylphosphine groups lean out. The two layers formed by the halogen bond chains are quasi-perpendicular to each other (83°) and they are separated thanks to the presence of the tricyclohexylphosphine groups that create very dense “insulator” alkyl barriers (Figure 2). In the crystal lattice other attractive forces, which can be discerned in addition to the XB, aid in the stabilization of the halogen bonded wires. A weak hydrogen bond appears between the fluorine atom (F2) on the XB donor and the adjacent hydrogen atom (H22) on the pyridyl pendant (2.610 Å). The reduction of the electron density on the pyridyl ring, as a consequence of the n → σ* nature of the XB connecting the two modules, increases the positive character of the hydrogen atom by enhancing the possibility to interact with electron-rich sites. Further weak interactions appear between the cyclohexyl hydrogen atoms and corresponding quasi-orthogonal perfluorinated ring, while F···H (2.632 Å) and C−H···π (2.742 and 2.766 Å) contacts link the two perpendicular chains. Co-Crystal 3b. The formation of co-crystal 3b was intended to study the versatility of the organometallic molecule 1 as a good halogen bond acceptor by expanding the perfluorinated module from diiodoperfluorobenzene 2a to 4,4′-diiodooctafluoro trans-stilbene 2b. The co-crystal 3b was obtained using the same procedure reported for 3a. The thermal analysis of the 3b single crystal revealed a behavior similar to that already seen in 3a: the crystal started to change color and became darker between 220 and 230 °C, and complete melting with decomposition was detected at 235 °C. The DSC analysis 301



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Figure 5. Corrugated metal-π-perfluorinated system in 3b pictured in red color space filling model. Color code for carbon and phosphorus as in Figure 1. Hydrogen atoms are omitted for clarity.

where the fluorinated rungs are sensibly twisted away from each other. This arrangement is due to interactions occurring between fluorine atoms and the electron-poor pyridyl and tetrafluorophenyl rings. Once again as in 3a, the XB drives the formation of 1D infinite chains wherein the metal-π-perfluorinated system iterates. Because of the absence of coplanarity between the XB donor and acceptor, the single wire is more corrugated as highlighted in Figure 5. Broad Band Dielectric Spectroscopy. The 3a and 3b materials were devised with the aim of exploring the possibility of obtaining low k hybrid organic−organometallic materials that are endowed with low permittivity values, negligible dielectric dispersion phenomena at high frequencies, and high thermal stability. The strategy adopted was to prepare materials in which a type-B hybrid macromolecule30 is obtained resulting from the concatenation process of basic units with high symmetry. In a type-B hybrid macromolecule, the dipole moment is perpendicular and rigidly attached to the main-chain skeleton of the macromolecule, with no long-range correlation between the dipole moments of repeat units of different chains.30 Thus, in these materials it is expected that the weak dipole−dipole interchain interactions would lower the overall permittivity of the systems, increase thermal stability, and inhibit dielectric dispersion at frequencies >1 kHz. The electric response of the hybrid supramolecular ribbons 3a and 3b was studied by broadband dielectric spectroscopy from 10−2 to 107 Hz and at temperatures ranging from 25 to 155 °C in increments of 10 °C. Figures 6a and 7a show the profiles at 1 Hz, 1 kHz, and 10 kHz of the real component of dielectric permittivity (ε′) versus temperature for 3a and 3b HOOSRs, respectively. It should be noted that in the explored temperature region and at frequencies lower than 1 kHz the values of ε′ of 3a and 3b are lower than that of SiO2 which has a value of ε′ = 3.9. SiO2 is commonly used as a standard insulating material in microelectronics. It should also be noted that in the investigated temperature and frequency range the ε′ values of 3b are lower than that of 3a, while the ε′ values of 3b are significantly lower than 1.54. These results can be explained by considering that the HOOSRs materials described here are 1D halogen bonded ribbons obtained by connecting very symmetric building blocks along the backbone chains such as 1 and 2a,b that are arranged alternately (see Scheme 1, Figures 1 and 4). In these materials a very small dipole moment is expected when (a) the coordination phenomena responsible for the binding of 1 and 2a,b units originate in a slightly distorted 1D polymer backbone chain such as that revealed in Figures 1 and 4; (b) the interchain interactions act to improve the structural distortion of the main chains. To clarify these points, the dependence on temperature of the dipole moment μ of 3a

Figure 6. Dependence of ε′ (a), ε″ (b), and tan δ (c) measured at 1 Hz, 1 kHz, and 10 kHz on temperature for 3a. ε′ values were obtained with an error less than 2%. The dotted lines in (b) and (c) show the α and β relaxations. The α and β peaks were determined by decomposing the ε″ profiles as a function of T with Gaussian curves. The solid lines are a guide for the eye and simply connect the experimental data (represented by markers).

and 3b was determined (Figure 8). A dipole is expected in the molecule due to small distorsions occurring in the monomer units along the polymeric chains and due to the presence of terminal groups in real material. μ was obtained by the equation31

⎛ ε′ − 1 ε − 1⎞ M N μ2 − ∞ · ⎜ ⎟· = 3ε0 3kT ε∞ + 1 ⎠ ρ ⎝ ε′ + 1

(1)

where ε′ is the real component of permittivity measured at 1 Hz and shown in Figures 6a,b. ε∞, which is the permittivity at high frequency of 3a and 3b, corresponds to the ε′ value at the intersection of the ε″ vs ε′ Cole−Cole plot at high frequency (see Supporting Information). M is the molecular weight of the asymmetric unit along the chains, ρ is the density determined by single crystal analyses (see Table 1), N is Avogadro’s number, ε0 is the permittivity in a vacuum, k is the Boltzmann constant, and T is the temperature. 302



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the orientational polarization of the obtained materials in these conditions is expected to be negligible. Further information on the correlation existing between the dielectric properties and structural features of 3a and 3b was determined by analyzing in detail the temperature spectra of both the imaginary component of permittivity (ε″) (Figures 6b and 7b) and of tan δ = ε″/ε′ (see Figures 6c and 7c). The ε″ and tanδ profiles reveal two relaxation phenomena, α and β. α is detected at T > 100 °C while β at T < 100 °C. α is associated with the diffusion of conformational states of the 1D HOOSR chains and thus to the segmental motion of 1D chains. It should be noted that α is centered at 130 °C and at T > 160 °C for the 3a and 3b materials, respectively. The β event is detected at ca. 70 and 90 °C for the 3a and 3b HOOSR materials, respectively. β is associated with the rotational fluctuation relaxation of the 2a,b organic moieties around the molecular axis of 1D HOOSR chains. The β relaxation mode in 3a is revealed at a temperature lower than in 3b. Thus, 2a units are more mobile than the 2b components along the 1D HOOSR chains. This result is in agreement with the structural information determined by the Xray single crystal shown in Figures 1 and 4, where it is possible to observe that in the absence of interchain interactions the 2a unit is able to fluctuate easily around the main chain axis, while 2b moieties, which are involved in extended interchain halogen bond and C−F···π interactions, as shown in Figure 4, present more hindered dynamics. For these reasons, α and β relaxation phenomena of 3b are shifted to higher temperatures. The detailed analysis of the tan δ profiles confirms the abovedescribed results and shows that the tan δ values of 3b: (a) are lower than 0.02 in the entire investigated temperature range (Figure 7c); and (b) are less than 0.004 at T < 100 °C. In addition, the dependence of the refraction indices n3a and n3b of 3a and 3b materials on temperature, respectively, are shown in Figure 8b. The mean values of the refraction index, determined using the equation ε∞ = (n)2, are on the order of ca. 1.69 and 1.19 for 3a and 3b, respectively. In summary, the halogen bonded supramolecular materials 3a and 3b present a negligible dielectric dispersion in the explored temperature and frequency ranges. Particularly, the 3b material has a permittivity value that is significantly lower than that of the silica reference and a tan δ < 0.05. These characteristics make 3b a very promising low k hybrid organic− organometallic material for application as dielectric films in next generation microelectronics. As suggested in the SEMATECH roadmap for intermetal dielectric constants,32 a good dielectric material for use in microelectronic devices should be endowed with (a) a real component of the dielectric constant lower than 3.5; (b) a tan δ < 0.05; and (c) ε′ and tan δ values varying as little as possible with temperature changes.

Figure 7. Dependence of ε′ (a), ε″ (b), and tan δ (c) measured at 1 Hz, 1 kHz, and 10 kHz on temperature for 3b. ε′ values were obtained with an error less than 2%. The dotted lines in (b) and (c) show the α and β relaxations. The α and β peaks were determined by decomposing the ε″ profiles as a function of T with Gaussian curves. The solid lines are a guide for the eye and simply connect the experimental data (represented by markers).

Figure 8. Dependence of μ and nx with x = 3a, 3b on temperature. μ and nx were determined by eq 1 and ε∞= (n)2, respectively. The solid lines are a guide for the eye and simply connect the experimental data (represented by markers).

4. CONCLUSION The crystalline materials 3a and 3b have been obtained through XB driven self-assembly of trans-[Pt(PCy3)2(CC-4-py)2] (1) with 1,4-diiodoperfluorobenzene (2a) and trans-1,2-bis(2,3,5,6-tetrafluoro-4-iodophenyl)-ethylene (2b), respectively, and the details of their structure have been determined through single crystal X-ray analyses. The electrical properties of 3a and 3b were analyzed by broadband dielectric spectroscopy at frequency and temperature ranges of 10−2 to 107 Hz and 25− 155 °C, respectively. The results indicated that, due to the dipole−dipole interactions present in bulk systems, the electric response of these composites is modulated by two relaxation events, attributed to the α and β modes of the polymer chains.

It should be noted that the dipole moment of 3b is slightly higher than that of 3a and it increases smoothly up to 140 °C thus indicating that μ depends on the structural distortion of the chains which is more pronounced in 3b than in 3a HOOSR materials. These results are in accordance with the abovedescribed structural features and confirm that the chain structural distortions generated by the interchain interactions are greater in 3b than in 3a. In addition, the values of μ < 1 at T < 70 °C suggest that the dielectric dispersion associated with 303



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In particular, analysis of the temperature spectra of ε′, ε″, and tan δ revealed that the dielectric properties of 3a and 3b were improved, owing to the weak interchain interactions between the type-B 1D HOOSR macromolecules of 3a and 3b materials that are more pronounced in 3b. 3b is a low k material with exceptionally promising dielectrical properties up to 1 MHz. In fact, it presents ε′ values lower than that of SiO2 (ε′ = 3.9) and a tan δ < 0.02. On the basis of the SEMATECH international roadmap [Semiconductor Industry Association. International Technology Roadmap for Semiconductors (ITRS), 2005 Update (http:// www.itrs.net/links/2005ITRS/interconnect2005.pdf], such characteristics classify the 3b product as a promising dielectric material for use in the development of organic microelectronic systems such as OTFT devices. The wide variety of crystal architectures based on MetLn complexes with different ancillary ligands (i.e., phosphines) and moieties suitable for noncovalent interactions involving electron deficient halogens opens new perspectives for using organometallic systems in achieving functional materials with tunable properties for advanced applications.

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(3) (a) Desiraju, G. R. Angew. Chem., Int. Ed. Engl. 2007, 46, 8342− 8356. (b) Piguet, C.; Borkovec, M.; Hamacek, J.; Zeckert, K. Coord. Chem. Rev. 2005, 249, 705−726. (4) (a) Natale, D.; Mareque-Rivas, J. C. Chem. Commun. 2008, 425− 437. (b) Sokolov, A. N.; Friscic, T.; MacGillivray, L. R. J. Am. Chem. Soc. 2006, 128, 2806−2807. (c) Davois, A. M.; Teague, S. J. Angew. Chem., Int. Ed. Engl. 1999, 38, 736−749. (d) Zordan, F.; Purver, S. L.; Adams, H.; Brammer, L. CrystEngComm 2005, 7, 350−354. (e) Chulkova, T. G.; Gushchin, P. V.; Haukka, M.; Kukushkin, V. Y. Inorg. Chem. Commun. 2010, 13, 580−583. (f) Au, R. H. W.; Fraser, C. S. A.; Eisher, D. J.; Jenninngs, M. C.; Puddephatt, R. J. Organometallics 2009, 28, 1719−1729. (g) Chakraborty, J.; Figge, H. M.; Sheldrick, W. S.; Banerjee, P. Polihedron 2005, 24, 771−776. (5) (a) Metrangolo, P.; Meyer, F.; Pilati, T.; Resnati, G.; Terraneo, G. Angew. Chem., Int. Ed. Engl. 2008, 47, 6114−6121. (b) Formiguè, M.; Batail, P. Chem. Rev. 2004, 104, 5379−5418. (c) Crihfield, A.; Hartwell, J.; Phelps, D.; Walsh, R. B.; Harris, J. L.; Payne, J. F.; Pennington, W. T.; Hanks, T. W. Cryst. Growth Des. 2003, 3, 313− 320. (d) Legon, A. C. Angew. Chem., Int. Ed. Engl. 1999, 38, 2686− 2714. (e) Roper, L. C.; Prasang, C.; Kozhevnikov, V. N.; Whitwood, A. C.; Karadakov, P. B.; Bruce, D. W. Cryst. Growth Des. 2010, 10, 3710− 3720. (6) (a) Kilpin, K. J.; Gower, M. L.; Telfer, S. G.; Jameson, G. B.; Crowley, J. D. Inorg. Chem. 2011, 50, 1123−1134. (b) Moussa, J.; Amouri, H. Angew. Chem., Int. Ed. Engl. 2008, 47, 1372−1380. (c) Moussa, J.; Wong, K. M. C.; Chamoreau, M. L.; Amouri, H.; Yam, V. W. W. Dalton Trans. 2007, 3526−3530. (d) Delahaye, S.; Loosli, C.; Liu, S. X.; Decurtins, S.; Labat, G.; Neels, A.; Loosli, A.; Ward, T. R.; Hauser, A. Adv. Funct. Mater. 2006, 16, 286−295. (7) (a) Shan, X. F.; Wang, D. H.; Tung, C. H.; Wu, L. Z. Tetrahedron 2008, 64, 5577−5582. (b) Ueda, K.; Sugimoto, T.; Faulmann, C.; Cassoux, P. Eur. J. Inorg. Chem. 2003, 2333−2338. (c) Smucker, B. W.; Hudson, J. M.; Omary., M. A.; Dunbar, K. R. Inorg. Chem. 2003, 42, 4714−4723. (8) (a) Fischer, R. A.; Woll, C. Angew. Chem., Int. Ed. Engl. 2009, 48, 2−6. (b) Friese, V. A.; Kurth, D. G. Coord. Chem. Rev. 2008, 252, 199−211. (c) Holliday, B. J.; Mirkin, C. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2022−2043. (9) (a) Schneider, H. J. Angew. Chem., Int. Ed. Engl. 2009, 48, 3924− 3977. (b) Notrhrop, B. H.; Zheng, Y. R.; Chi, K. W.; Stang, P. J. Acc. Chem. Res. 2009, 42, 1554−1563. (c) Han, Z.; Zhao, Y.; Peng, J.; Tian, A.; Liu, Q.; Ma, J.; Wang, E.; Hu, N. CrystEngComm 2005, 7, 380− 387. (d) Kimizuka, N. Adv. Mater. 2000, 12, 1461−1463. (10) (a) Katz, H. E.; Hong, X. M.; Dodabalapur, A.; Sarpeshkar, R. J. Appl. Phys. 2002, 91, 1572−1567. (b) Drury, C. J.; Mutsaers, C. M. J.; Hart, C. M.; Matters, M.; de Leeuw, D. M. Appl. Phys. Lett. 1998, 73, 108−110. (c) Halik, M.; Klauk, H.; Zschieschang, U.; Kriem, T.; Schmid, G.; Radlik, W.; Wussow, K. Appl. Phys. Lett. 2002, 81, 289− 291. (d) Halik, M.; Klauk, H.; Zschieschang, U.; Schmid, G.; Radlik, W.; Ponomarenko, S.; Kirchmeyer, S.; Weber, W. J. Appl. Phys. 2003, 93, 2977−2981. (e) Gelinck, G. H.; Geuns, T. C. T.; de Leeuw, D. M. Appl. Phys. Lett. 2000, 77, 1487−1489. (f) Sirringhaus, H.; Tessler, N.; Friend, R. H. Science 1998, 280, 1741−1744. (g) Haukka, S.; Root, A. J. Phys. Chem. 1994, 98, 1695−1703. (11) Maier, G. Prog. Polym. Sci. 2001, 26, 3−65. (12) (a) Dimitrakopoulos, C. D.; Malenfant, P. R. L. Adv. Mater. 2002, 14, 99−117. (b) Guillaud, G.; Simon, J.; Germain, J. P. Coord. Chem. Rev. 1998, 178−180, 1433−1484. (c) Lavina, S.; Negro, E.; Pace, G.; Gross, S.; Depaoli, G.; Vidali, M.; Di Noto, V. J. Non-Cryst. Solids 2007, 353, 2878−2888. (d) Gross, S.; Di Noto, V.; Schubert, U. J. Non-Cryst. Solids 2003, 322, 154−159. (e) Di Noto, V; Boeer, A. B.; Lavina, S.; Muryn, C. A.; Bauer, M.; Timco, G. A.; Negro, E.; Rancan, M.; Winpenny, R. E. P.; Gross, S. Adv. Funct. Mater. 2009, 19, 1−11. (13) (a) Lu, W.; Chen, Y.; Roy, V. A. L.; Chui, S. S. Y.; Che, C. M. Angew. Chem., Int. Ed. Engl. 2009, 48, 7621−7625. (b) Jiung, H.; Lin, W. J. Organomet. Chem. 2005, 690, 5159−5169. (14) (a) Frischmann, P. D.; Guieu, S.; Tabeshi, R.; MacLachlan, M. J. J. Am. Chem. Soc. 2010, 132, 7668−7675. (b) Bassetti, M. Eur. J. Inorg. Chem. 2006, 4473−4482. (c) Kuroiwa, K.; Oda, N.; Kimizuka, N. Sci.

ASSOCIATED CONTENT

S Supporting Information *

IR and DSC spectra of 1 and 3a,b, geometrical parameters of other noncovalent interactions in 3a,b, experimental XRPD of 3a,b, Cambridge Structural Database list of N···I distances involving 1,4-diiodotetrafluorobenzene as XB donor. This material is available free of charge via the Internet at http:// pubs.acs.org.

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AUTHOR INFORMATION Corresponding Author *E-mail: [email protected]. ACKNOWLEDGMENTS This work was supported by PRIN2008KMP97E. P.M., G.R., and G.T. thank Fondazione Cariplo Project 2150, NewGeneration Fluorinated Materials as Smart Reporter Agents in 19F MRI and Project 2010-1351, Development of a Technology Platform between the South and the North of Europe: Exchange Research Program between Politecnico di Milano and VTT-Technical Research center of Finland (S2N).

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DEDICATION Dedicated to the memory of Klaus Müller, dear friend, great scientist, and irreplaceable co-worker. REFERENCES

(1) (a) Saalfrank, R. W.; Demleitner, B. In Transition Metals in Supramolecular Chemistry; Sauvage, J. P., Ed.; Wiley & Sons: Chichester, 1999; Vol. 5, Chapter 1, pp 1−52. (b) Haiduc, I, Edilmann, F. T. Supramolecular Organometallic Chemistry; Wiley VCH: New York, 2000. (c) Batten, S. R., Neville, S. M., Turner, D. R. Coordination Polymers. Design, Analysis and Applications; RCS Publishing: Cambridge, 2009. (d) Kurth, D. G. Sci. Technol. Adv. Mater. 2008, 9, 1−25. (2) (a) Corriu, R.; Mehdi, A.; Reyè, C. J. Organomet. Chem. 2004, 689, 4437−4450. (b) Manciu, F.; Rampazzo, E.; Tecilla, P.; Tonellato, U. Chem.Eur. J. 2006, 12, 1844−1854. (c) Xia, Y.; Yang, P.; Sun, Y.; Wu, Y.; Mayers, B.; Gates, B.; Yin, Y.; Kim, F.; Han., H. Adv. Mater. 2003, 15, 353−389. (d) Philp, D.; Stoddard, J. F. Angew. Chem., Int. Ed. Engl. 1996, 35, 1154−1196. 304



Article

Tech. Adv. Mater. 2006, 7, 629−634. (d) Gerhardt, W. W.; Zucchero, A. J.; South, C. R.; Bunz, U. H. F.; Weck, M. Chem.Eur. J. 2007, 13, 4467−4474. (e) Au, R. H. W.; Jennings, M. C.; Puddephatt, R. J. Eur. J. Inorg. Chem. 2009, 1526−1534. (15) (a) Shamnugaraju, S.; Bar, A. K.; Chi, K. W.; Mucherjen, P. S. Organometallics 2010, 29, 2971−2980. (b) Machut, C.; Patrigeon, J.; Tilloy, S.; Briciut, H.; Hapiot, F.; Monflier, E. Angew. Chem., Int. Ed. Engl. 2007, 46, 3040−3042. (c) Haxwell, S. M.; Espallargas, G. M.; Bradshaw, D.; Rosseinsky, M. J.; Prior, T. J.; Florence, A. J.; van de Streek, J.; Brammer, L. Chem. Commun. 2007, 1532−1534. (d) Kitagawa, S.; Kitaura, R.; Noro, S. Angew. Chem., Int. Ed. Engl. 2004, 43, 2334−2375. (e) Bureekae, W. S.; Shomirura, S.; Kitakawa, S. Sci. Technol. Adv. Mater. 2008, 9, 1−12. (16) (a) Lu, W.; Chen, Y.; Roy, V. A. L.; Chiu, S. S. Y.; Che, C. Angew. Chem., Int. Ed. Engl. 2009, 48, 7621−7625. (b) Jiang, H.; Lin, W. J. Organomet. Chem. 2005, 690, 5159−5169. (17) (a) Cooke, M. W.; Chartrand, D.; Hanan, G. S. Coord. Chem. Rev. 2008, 252, 903−921. (b) Umakoshi, K.; Kojima, T.; Saito, K.; Akatsu, S.; Onischi, M.; Ishizaka, S.; Kitamura, N.; Nakao, Y.; Sakaki, S.; Ozawa, Y. Inorg. Chem. 2008, 47, 5033−5035. (c) Ziessel, R.; Hissler, M.; El-ghayoury, A.; Harriman, A. Coord. Chem. Rev. 1998, 178−180, 1251−1298. (18) (a) Kuroiwa, K.; Shibata, T.; Sasaki, S.; Ohba, M.; Takahara, A.; Kunitake, T.; Kimizuka, N. J. Pol. Sci.: Part A: Polym. Chem. 2006, 44, 5192−5202. (b) Shirahata, T.; Kibune, M.; Mausato, M.; Kawashima, T.; Saito, G.; Imakubo, T. J. Mater. Chem. 2006, 16, 3381−3390. (19) (a) Cavallo, G.; Metrangolo, P.; Pilati, T.; Resnati, G.; Sansotera, M.; Terraneo, G. Chem Soc. Rev. 2010, 39, 3772−3783. (b) Yamamoto, H. M. Riken Rev. 2002, 46, 3−6. (c) Huang, X. Q.; Zhang, H. H.; Guo, C. Y.; Zhou, Z. Y.; Zheng, N. F. Angew. Chem., Int. Ed. Engl. 2009, 48, 1−6. (d) Jude, H.; Sinclair, D. J.; Das, N.; Sherburn, M. S.; Stang, P. J. J. Org. Chem.. 2006, 71, 4155−4163. (e) Ghosh, S.; Batten, S. R.; Turner, D. R.; Mukherjee, P. S. Organometallics 2007, 26, 3252−3255. (f) Saba, B. K.; Nangia, A. Cryst. Growth Des. 2007, 7, 393−401. (20) (a) Lu, W.; Naj, K. M.; Che, C. M. Chem. Asian J. 2009, 4, 830− 834. (b) Kimizuka, N.; Oda, N.; Kunitake, T. Inorg. Chem. 2000, 39, 2684−2689. (c) Bremi, J.; Fontana, M.; Caseri, W.; Smith, P. Macromol. Symp. 2006, 235, 80−88. (d) Fontana, M.; Chanzy, H.; Caseri, W. R.; Smith, P.; Schenning, A. P. H. J.; Meijer, E. W.; Gröhn, F. Chem. Mater. 2002, 14, 1730−1735. (e) Femoni, C.; Iapalucci, M. C.; Longoni, G.; Lovato, T.; Stagni, S.; Zacchini, S. Inorg. Chem. 2010, 49, 5992−6004. (21) (a) Belluco, U.; Bertani, R.; Michelin, R. A.; Mozzon, M. J. Organomet. Chem. 2000, 600, 37−55. (b) Cardolaccia, F.; Li, Y.; Shanzu, K. S. J. Am. Chem. Soc. 2008, 130, 2535−2545. (c) Xu, R.; Schweizer, W. B.; Frauenrath, H. J. Am. Chem. Soc. 2008, 130, 11437− 11445. (d) Wong, W. Y.; Ho, C. L. Coord. Chem. Rev. 2006, 250, 2627−2690. (e) Tam, A. Y. Y.; Wong, K. M. C.; Yam, V. W. W. Chem.Eur. J. 2009, 15, 4775−4778. (f) Saha, B. K.; Nangia, A. Cryst. Growth Des. 2007, 7, 393−401. (g) La Groia, A.; Ricci, A.; Bassetti, M.; Masi, D.; Bianchini, C.; Lo Sterzo, C. J. Organomet. Chem. 2003, 683, 406−420. (h) Shiotsuka, M.; Nishito, N.; Keyaki, K.; Nozaki, K. Dalton Trans. 2010, 29, 1831−1835. (i) Chen, Y.; Li, K.; Lu, W.; Chui, S. S. Y.; Ma, C. W.; Che, C. M. Angew. Chem., Int. Ed. Engl. 2009, 48, 9909−9913. (22) (a) Bertani, R.; Sgarbossa, P.; Venzo, A.; Lely, F.; Amati, M.; Resnati, G.; Pilati, T.; Metrangolo, P.; Terraneo, G. Coord. Chem. Rev. 2010, 254, 677−695. (b) Brammer, L.; Espallargas, G. M.; Libri, S. CrystEngComm 2008, 10, 1712−1727. (23) Mareque-Rivas, J. C.; Brammer, L. Coord. Chem. Rev. 1999, 183, 43−80. (24) Adams, C. J.; Bowen, L. E. Dalton Trans. 2005, 2239−2240. (25) Yoshida, T.; Otsuka, S.; Jones, D. G.; Spencer, J. L.; Binger, P.; Brinkmann, A.; Wedemann, P. Inorg. Synth. 1990, 28, 113−114. (26) Baldrighi, M.; Metrangolo, P.; Meyer, F.; Pilati, T.; Proserpio, D.; Resnati, G.; Terraneo, G. J. Fluorine Chem. 2010, 131, 1218−1224. (27) Di Noto, V. J. Phys. Chem. B 2002, 106, 11139−11154.

(28) Burla, M. C.; Camalli, M.; Carrozzini, B.; Cascarano, G. L.; Giacovazzo, C.; Polidori, G.; Spagna, R. J. Appl. Crystallogr. 2003, 36, 1103−1112. (29) Sheldrick, G. M. Acta Crystallogr. A 2008, 64, 112−122. (30) (a) Adachi, K. In Dielectric Spectroscopy of Polymeric Materials. Fundamentals and Applications; Runt, J. P.; Fitzgerald, J. J., Eds.; American Chemical Society: Washington, DC, 1997; pp 261−282. (b) Mead, D. J.; Fuoss, R. M. J. Am. Chem. Soc. 1942, 64, 2389−2393. (31) Ku, C. C.; Liepins, R. In Electrical Properties of Polymers: Chemical Principles; Hanser: Munich, 1987. (32) Semiconductor Industry Association. International Technology Roadmap for Semiconductors (ITRS), 2005 Update (http://www.itrs. net/links/2005ITRS/interconnect2005.pdf).

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Interplay between Structural and Dielectric Features of New Low k

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