COMMUNICATION pubs.acs.org/crystal
Halogen-Bonded, Eight-fold PtS-Type Interpenetrated Supramolecular Network. A Study toward Redundant and Cross-Bar Supramolecular Nanowire Crystal Published as part of the Crystal Growth & Design virtual special issue on “Halogen Bonding in Crystal Engineering: Fundamentals and Applications". Julien Lieffrig,*,†,‡ Hiroshi M. Yamamoto,*,†,‡,§,|| Tetsuro Kusamoto,† Henbo Cui,† Olivier Jeannin,‡ Marc Fourmigue,‡ and Reizo Kato† †
RIKEN, Wako, Saitama 351-0198, Japan SCR, Universite Rennes 1, Rennes 35042, France § JST-PRESTO, Kawaguchi, Saitama 332-0012, Japan Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502, Japan
)
‡
bS Supporting Information ABSTRACT: Making crystalline organic conducting nanowires will allow three-dimensional nanoscale wiring, owing to their periodic arrangement in the solid state. In order to find new motifs for insulation sheaths in a crystal, new large and rigid spacer molecules containing iodine atoms have been successfully synthesized. One novel nonplanar aromatic tecton with an extended skeleton, 2,20 ,4,40 ,6,60 -hexafluoro-3,30 ,5,50 -tetrakis((4-(iodoethynyl)phenyl)ethynyl)biphenyl (1) has formed halogen-bonded supramolecular selfassemblies in the presence of halide anions. Bis(propylenedithio)tetrathiafulvalene (PT), a precursor of organic conductors, was electrochemically oxidized to the cation radical state as Cl or Br salt and cocrystallized with this neutral iodinated tecton 1 to form multicomponent supramolecular self-assembled isostructural crystalline salts PT(1)X (X = Cl, Br). X-ray structure analysis, conductivity, and magnetic susceptibility measurements were performed on these ternary salts. Owing to the pseudotetrahedral symmetry of the tecton, an eight-fold interpenetrated PtS-type network of class Ia has been identified and some clues for future developments of cross-bar nanowire monocrystals have been obtained. In these layer-by-layer type crystals, the fully oxidized PT molecules adopt a rare purely two-dimensional S = 1/2 Heisenberg square lattice type organization with weak antiferromagnetic interactions.
I
n recent decades, the bottom-up strategy has shown its efficiency to fabricate molecular devices. Molecules with tunable electric or magnetic properties can be assembled together to lead to novel nanomaterials. Self-assembling is a valuable method to order molecules in the solid state, but the structure prediction of these nanoarchitectures remains a challenge to control their organization.1 Recently, in addition to well-known interactions such as hydrogen bonds, van der Waals interactions, etc., halogen bonds have attracted the interest of many groups.2 Owing to its strength, specificity, and strong directionality, halogen bonding is a powerful tool which can be used to orient the molecules in some desired directions and to improve the control of their arrangement at the supramolecular scale. This ability to predict the organization of self-assembled nanostructures to some extent would open up new perspectives in the field of crystal engineering and for the design of nanoarchitectures. This interaction has proved particularly efficient in the solid state “coordination” of anions,3 and this ability was recognized as a powerful tool for the r 2011 American Chemical Society
elaboration of organic conductors based on cation radical salts, where the counterion can be tightly halogen-bonded to the iodinated radical cations.4,5 Nanowires have been intensively studied, but their proper alignment remains a main issue.6 Making crystalline nanowires solves this problem, since their organization is controlled by their periodic arrangement in the solid state. By crystal engineering, our group has been developing various nanowire crystals where an insulating network made of halide anions halogen-bonded to rigid neutral molecules containing iodine atoms is sheathing conductive stacks of radical cations, as illustrated in Figure 1.7 By changing the size and the structure of the neutral spacer molecule or/and the cation, nanowires with different arrangements can be obtained either incorporating two (or more) cation Received: July 6, 2011 Revised: September 5, 2011 Published: September 14, 2011 4267
dx.doi.org/10.1021/cg200843w | Cryst. Growth Des. 2011, 11, 4267–4271
Crystal Growth & Design
Figure 1. Example of a crystalline nanowire in the (TSF)(HFTIEB)Cl salt where a neutral tetrabranched iodinated molecule HFTIEB [1,10 ,3,30 ,5,50 -hexafluoro-2,20 ,4,40 -tetrakis(iodoethynyl)biphenyl], halogen-bonded to chloride anions, forms channels for stacks of tetraselenafulvalene (TSF) cation radicals (see ref 7e).
Scheme 1. Building Blocks (A, B) Used for the Synthesis of the Target Molecules 1
radical stacks within one single channel or increasing the thickness of the insulating sheath made of halogen-bonded neutral iodinated molecules and halide anions. In order to modify the structure of these nanoassemblies, we decided to design a new skeleton for these self-assembled networks, in our case newly extended neutral molecules containing activated iodine atoms for halogen bonding. Here, we report on the synthesis of a new rigid spacer tetrabranched molecule with pseudotetrahedral symmetry (1) (Scheme 1). New self-assembled supramolecular networks associating by halogen bonding molecule 1 with Cl or Br anions incorporate the cation radical of a tetrathiafulvalene derivative, giving rise to a ternary system with embedded S = 1/2 radical species. Molecule 1 has been synthesized from known building blocks A and B (Scheme 1; see the Supporting Information for details).
COMMUNICATION
Figure 2. ORTEP view (at the 50% probability level) of the components of the ternary system PT(1)Br.
The asymmetric p-diethynylbenzene precursor8 A is used as branches to extend the core (precursor B)7e of the final molecules. 1 can be obtained from these precursors in two steps: first a Sonogashira reaction9 to connect the four branches A to the core B, followed by a one-pot deprotectioniodination reaction.10 Gel permeation chromatography (using THF as an eluant) afforded pure compound 1 in 60% yield from core molecule B. Electrocrystallization experiments11 of the bis(propylenedithio)tetrathiafulvalene TTF derivative PT were performed in the presence of PPh4Cl or PPh4Br together with the neutral, tetrabranched iodinated molecule 1. Isostructural crystals formulated as PT(1)Br and PT(1)Cl with 1:1:1 stoichiometry have been obtained.12 They crystallize in the orthorhombic system, space group Ibam, with the Cl or Br anion at the center of the unit cell, the neutral molecule 1 center of gravity on a (222) position, and the PT cation’s center of gravity on a (...2/m) position (Figure 2). The two isostructural salts adopt a complex structure (Figure 3), with mixed PT•+ cation/Br (or Cl) layers alternating with the neutral 1 molecules along the c axis. The PT molecule with its distorted seven-membered outer rings adopts a chair conformation. The nonplanar neutral molecule 1 exhibits a twist angle between the two trifluoroaryl groups of 66.2(2)°. The halide anion is halogenbonded to four iodine atoms of four different 1 molecules in a square planar motif. The geometrical characteristics of the halogen bond interaction are collected in Table 1 and demonstrate the strength of these interactions. In both bromide and chloride ternary salts, the connectivity pattern around one halide anion leads to the formation of a complex sublattice shown in Figure 4, adopting a rare PtS-like structure where we could observe large channels noted A and B. Due to the twisted structure of 1, the major channel (channel A) forms three-dimensional cross-bar arrangements (see also the animation in the Supporting Information). These channels would have a reality if the structure was not characterized by a heavy interpenetration to avoid the presence of voids. Indeed, as 4268
dx.doi.org/10.1021/cg200843w |Cryst. Growth Des. 2011, 11, 4267–4271
Crystal Growth & Design
COMMUNICATION
Figure 3. Projection view of the unit cell of PT(1)Br on the ac plane.
Table 1. Halogen Bond Characteristics in the Two PT(1)X Compoundsa compd
I 3 3 3 (Cl,Br) CI 3 3 3 (Cl,Br) dist (Å) reduction ratio ang (deg)
ref
PT(1)Br
3.2932(7)
0.84
170.2(2)
this work
PT(1)Cl
3.1366(13)
0.83
170.3(5)
this work
(TSF) 3.0373(12) (HFTIEB)Cl
0.80
175.6(2)
7e
a
The halogen bond reduction ratio is defined as DIX/(RvdW + RP), where DIX is the interatom distance, RvdW the van der Waals radius of iodine (1.98 Å), and RP the Pauling ionic radius of Cl (1.81 Å) or Br (1.95 Å).
shown in Figure 5, the full network contains an eight-fold interpenetrated PtS-type net of class Ia, an exceptionally rare example, as, among all reported interpenetrated structures, only 1.3% adopt a PtS topology and only 3.3% exhibit an eight-fold interpenetration degree.13 Note also that interpenetrated structures based on halogen bonding interactions have only been mentioned recently, based on tetrakis(4-iodotetrafluorophenyl)pentaerythritol derivatives as tetradentate halogen bond donors.14 Such a structure opens up good perspectives for accommodating multiple strands of conducting nanowires if one could prevent interpenetration. This structural motif provides a clue to realize a cross-bar nanowire crystal (see also Figure S2 in the Supporting Information).15 Indeed, by isolating one sublattice,
we can easily notice that, as anticipated, 1 is able to form large channels (Figure 4), as previously observed with other planar tectons.7 However, the long branches of this spacer and its pseudotetrahedral symmetry result in a three-dimensional interpenetrated network. Indeed, our previous tectons were linear or with a low distortion from planarity,7 allowing them to easily stack on top of each other and thus to form one-dimensional systems, as illustrated in Figure 1. Furthermore, thanks to their smaller size, they were able to adapt their solid state organization to the constraints of the stacked radical cations. In the present case, the strongly distorted structure and longer arms of 1 are driving the organization of the whole structure into a highly interpenetrated network to prevent voids, which are a source of instability.
’ MAGNETIC PROPERTIES We have seen above that, in the PT(1)X salt, the PT molecule organization is driven by the anionic network constraints, which leads to the formation of a layered structure (Figure 3). Indeed, all PT layers are isolated from each other by a layer of neutral iodinated molecules (more than 20 Å). PT molecules are fully oxidized to a monocationic state with a 1/2-spin. In most cases, these radical cations tend to form dimers due to strong overlap of their frontier orbitals. Nevertheless, in our case, PT•+ species adopt a rare purely two-dimensional square lattice configuration (Figure 6) where each cation interacts with four neighboring molecules through one single interaction involving overlap with the outer propylene moieties.16 Accordingly, the calculated absolute value of the transfer integral between two radical cations 4269
dx.doi.org/10.1021/cg200843w |Cryst. Growth Des. 2011, 11, 4267–4271
Crystal Growth & Design
COMMUNICATION
Figure 6. View of one PT •+ ,Br layer in PT(1)Br, showing the essentially non-interacting cation radicals. Figure 4. View of one halogen-bonded sublattice with the PtS structure of PT(1)Br.
that no channels were obtained as desired toward the formation of multiwires, precious information was gathered to lead to crossbar supramolecular nanowires.
’ ASSOCIATED CONTENT
bS
Supporting Information. Crystallographic files in CIF format; details on synthesis, structures, and magnetic susceptibility data (as pdf file); and animation showing the structure (as avi file). This material is available free of charge via the Internet at http://pubs.acs.org.
’ AUTHOR INFORMATION Corresponding Author
Figure 5. Eight-fold interpenetrated network in PT(1)Br. The eight sublattices are drawn with different colors. The square-planar Br coordination is shown with gray squares.
(5.2 104 eV) is negligible, so we expect very small intermolecular interactions (Jcalc ≈ t2/U ≈ 2.2 103 cm1 with U ≈ 1 eV).17 As a consequence, the salt is completely insulating and the temperature dependence of its magnetic susceptibility follows a CurieWeiss law with a Curie constant of 0.377(10) emu 3 K 3 mol1 and a Weiss constant of 4.5(2) K. The Curie constant is very close to the theoretical value for isolated half spin molecules (0.375 emu 3 K 3 mol1 with g = 2), which confirms that the spins are completely localized. Note that this system provides an ideal example of purely 2D Heisenberg tetragonal lattice without antiferromagnetic order.16 The weak intermolecular interaction might be favorable for further physical measurements, because it would allow studying the magnetic influence on this type of lattice at moderate magnetic fields. In summary, we have shown that the nonplanar tetrabranched iodinated spacer 1 can be successfully electrocrystallized with PT tetrathiafulvalene derivative and halide ions to afford a rare eightfold interpenetrated PtS-type supramolecular network thanks to strong halogen bonding interactions. Moreover, despite the fact
*J.L.: Sciences Chimiques de Rennes (SCR), Universite Rennes 1 et CNRS, Campus de Beaulieu B^at 10C, 35042 Rennes, France. Telephone: (33) 2 23 23 52 43. Fax: (33) 2 23 23 67 32. E-mail: julien.lieff
[email protected]. *H.M.Y.: RIKEN, Hirosawa, Wako, Saitama 351-0198, Japan. Telephone: +81-48-467-9410. Fax: +81-48-462-4661. E-mail:
[email protected].
’ ACKNOWLEDGMENT This work was partially supported by a Grant-in-Aid for Scientific Research (Nos. 20681014 and 22224006) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan. Financial support from ANR (France) under Contracts ANR-08-BLAN-0140-02 and ANR-08-BLAN-0091-02 is gratefully acknowledged together with support from the FrenchJapanese CNRS GDRI. We also thank Florian Moreau (Rennes) for his help with the TOPOS software. ’ REFERENCES (1) (a) Lehn, J. M. Angew. Chem., Int. Ed. Engl. 1990, 29, 1304. (b) Lehn, J. M. Supramolecular Chemistry: Concepts and Perspectives,; VCH: Weinheim, 1995. (c) Desiraju, G. R. The Crystal as a Supramolecular Entity. In Perspectives in Supramolecular Chemistry; John Wiley & Sons: 1995. (d) Desiraju, G. R. Angew. Chem., Int. Ed. Engl. 1995, 34, 2311. (e) Atwood, J. L.; Steed, J. W. Supramolecular Chemistry; John Wiley & Sons Ltd: Chichester, U.K., 2000. (f) Desiraju, G. R. Nature 2001, 412, 397. 4270
dx.doi.org/10.1021/cg200843w |Cryst. Growth Des. 2011, 11, 4267–4271
Crystal Growth & Design (g) Whitesides, G. M.; Boncheva, M. Proc. Natl. Acad. Sci. U.S.A. 2002, 99, 4769. (2) (a) Metrangolo, P.; Resnati, G. Chem.—Eur. J. 2001, 7, 2511. (b) Metrangolo, P.; Meyer, F.; Pilati, T.; Resnati, G.; Terraneo, G. Angew. Chem., Int. Ed. 2008, 47, 6114. (c) Metrangolo, P.; Resnati, G. Science 2008, 321, 918. (d) Rissanen, K. CrystEngComm 2008, 10, 1107. (e) Zordan, F.; Brammer, L.; Sherwood, P. J. Am. Chem. Soc. 2005, 127, 5979. (3) (a) Custelcean, R. Chem. Soc. Rev. 2010, 39, 3675. (b) Metrangolo, P.; Pilati, T.; Terraneo, G.; Biella, S.; Resnati, G. CrystEngComm 2009, 11, 1187. (c) Cavallo, G.; Metrangolo, P.; Pilati, T.; Resnati, G.; Sansotera, M.; Terraneo, G. Chem. Soc. Rev. 2010, 39, 3772. (d) Kilah, N. L.; Wise, M. D.; Serpell, C. J.; Thompson, A. L.; White, N. G.; Christensen, K. E.; Paul, D.; Beer, P. D. J. Am. Chem. Soc. 2010, 132, 11893. (4) (a) Fourmigue, M.; Batail, P. Chem. Rev. 2004, 104, 5379. (b) Fourmigue, M. Struct. Bonding (Berlin) 2008, 126, 181. (c) Fourmigue, M. Curr. Opin. Solid State Mater. Sci. 2009, 13, 36. (5) (a) Imakubo, T.; Sawa, H.; Kato, R. Synth. Met. 1995, 73, 117. (b) Imakubo, T.; Shirahata, T.; Herve, K.; Ouahab, L. J. Mater. Chem. 2006, 16, 162. (6) (a) Hu, J.; Odom, T. W.; Lieber, C. M. Acc. Chem. Res. 1999, 32, 435. (b) Duan, X.; Huang, Y.; Cui, Y.; Wang, J.; Lieber, C. M. Nature 2001, 409, 66. (c) Wei, B. Q.; Vajtai, R.; Jung, Y.; Ward, J.; Zhang, R.; Ramanath, G.; Ajayan, P. M. Nature 2002, 416, 495. (d) Huang, Y.; Duan, X.; Wei, Q.; Lieber, C. M. Science 2001, 291, 630–633. (7) (a) Yamamoto, H. M.; Yamaura, J.-I.; Kato, R. J. Am. Chem. Soc. 1998, 120, 5905. (b) Yamamoto, H. M.; Yamaura, J.-I.; Kato, R. Synth. Met. 1999, 102, 1448. (c) Yamamoto, H. M.; Kato, R. Chem. Lett. 2000, 970. (d) Kosaka, Y.; Yamamoto, H. M.; Nakao, A.; Kato, R. Bull. Chem. Soc. Jpn. 2006, 79, 1148. (e) Yamamoto, H. M.; Kosaka, Y.; Maeda, R.; Yamaura, J.-I.; Nakao, A.; Nakamura, T.; Kato, R. ACS Nano 2008, 2, 143. (8) Rodriguez, J. G.; Tejedor, J. L.; La Parra, T.; Diaz, C. Tetrahedron 2006, 62, 3355. (9) (a) Mattern, D. L. J. Org. Chem. 1983, 48, 4772. (b) Rodriguez, J. G.; Esquivias, J.; Lafuente, A.; Diaz, C. J. Org. Chem. 2003, 68, 8120. (c) Leroux, F.; Maurin, M.; Nicod, N.; Scopelliti, R. Tetrahedron Lett. 2004, 45, 1899–1902. (10) Nishikawa, T.; Shibuya, S.; Hosokawa, S.; Isobe, M. Synlett 1994, 485. (11) Single crystals were grown electrochemically in a H-shaped 20 mL cell under an argon atmosphere at constant current at 20 °C. The PT molecule (7.2 mg), 1 (50.1 mg), and tetraphenylphosphonium halide (9.9 mg) were dissolved in a mixture of chlorobenzene/THF/methanol (16/4/1, 20 mL). Under an argon atmosphere, a constant current of 0.5 μA was applied through platinum electrodes for 8 days. After the electrolysis, crystals with good quality were harvested on the anode. (12) Data were collected on a Rigaku Mercury CCD diffractometer. Structures were solved by direct methods using SIR92 (Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G. L.; Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna, R. J. Appl. Crystallogr. 1999, 32, 115) and refined (SHELXL-97) by full-matrix least-squares methods as implemented in the WinGX software package ( Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837). An empirical absorption (multiscan) correction was applied. Hydrogen atoms were introduced at calculated positions (riding model) included in the structure factor calculation but not refined. Solvent molecules were squeezed using the Squeeze option (Sluis, P. v. d.; Spek, A. L. Acta Crystallogr., Sect. A 1990, 46, 194) of Platon software (Spek, A. L. Acta Crystallogr., Sect. A 1990, 46, C34). Crystallographic data for PT(1)Br: C64H28BrF6I4S8, Mr = 1754.85, orthorhombic, space group Ibam, a = 12.098(2) Å, b = 16.807(3) Å, c = 34.290(7) Å, V = 6972(2) Å3, T = 293 K, Z = 4, μ = 2.653, R1 = 0.0750 for 2535 data with Fo > 2σ(I), wR2 = 0.2163 for 4177 unique data (all data 23719, Rint = 0.0476). Crystallographic data for PT(1)Cl: C64H28ClF6I4S8, Mr = 1710.48, orthorhombic, space group Ibam, a = 11.810(2) Å, b = 16.572(3) Å, c = 33.961(7) Å, V = 6647(2) Å3, T = 293
COMMUNICATION
K, Z = 4, μ = 2.222, R1 = 0.0787 for 1044 data with Fo > 2σ(I), wR2 = 0.2674 for 3041 unique data (all data 16852, Rint = 0.0672). (13) (a) Batten, S. B. CrystEngComm 2001, 18, 1. (b) Blatov, V. A.; Carlucci, L.; Ciani, G.; Proserpio, D. M. CrystEngComm 2004, 6, 377. (14) (a) Metrangolo, P.; Meyer, F.; Pilati, T.; Proserpio, D. M.; Resnati, G. Chem.—Eur. J. 2007, 13, 5765. (b) Baldrighi, M.; Metrangolo, P.; Meyer, F.; Pilati, T.; Proserpio, D. M.; Resnati, G.; Terraneo, G. J. Fluor. Chem. 2010, 131, 1218. (15) (a) Melosh, N. A.; Boukai, A.; Diana, F.; Gerardot, B.; Badolato, A.; Petroff, P. M.; Heath, J. R. Science 2003, 300, 112. (b) Parthenopoulos, D. A.; Rentzepis, P. M. Science 1989, 245, 843. (c) Heath, J. R.; Kuekes, P. J.; Snider, G. S.; Williams, R. S. Science 1998, 280, 1716. (16) Lines, M. E. J. Phys. Chem. Solids 1970, 31, 101. (17) Liu, H. L.; Chou, L. K.; Abboud, K. A.; Ward, B. H.; Fanucci, G. E.; Granroth, G. E.; Canadell, E.; Meisel, M. W.; Talham, D. R.; Tanner, D. B. Chem. Mater. 1997, 9, 1865.
4271
dx.doi.org/10.1021/cg200843w |Cryst. Growth Des. 2011, 11, 4267–4271
