Balancing framework densification with charged, halogen-bonded-pi-conjugated linkages: [PPh4]2{[E-TTF-I2][Re6Se8(CN)6]} versus [PPh4]2[EDT-TTF-I]2{[EDT-TTF-I][Re6Se8(CN)6]}

The ionic character of a set of two redox linkages and strong, directional halogen bonding at the organic-inorganic interface compromise to produce two materials sharing a common two-dimensional net, eventually extended in a third dimension, although two of the six symmetrical halogen bond acceptors ultimately remain uninvolved as a result of charge densification.     

Novel octahedral tungsten sulfidocyanide cluster anion [W6S8(CN)6]6-

Novel tungsten octahedral sulfidocyanide cluster compounds Na6[W6S8(CN)6].18DMSO 1 and K6[W6S8(CN)6] 2 have been synthesized and characterized by X-ray crystallography and NMR spectroscopy.     

Polymerization of 1,4-bis[2-(N-vinyl)pyrrolyl]benzene

Polymers of 1,4-bis[2-(N-vinyl)pyrrolyl]benzene with free N-vinyl groups in side chains are synthesized in the presence of AIBN (2–5 wt %, 70°C) with a yield of up to 34% and a molecular mass of up to 11.5 × 10³. In the presence of cationic catalysts (Me₃SiCl, the LiBF₄-dimethoxyethane system, and BF₃ · OEt₂), 1,4-bis[2-(N-vinyl)pyrrolyl]benzene gives macromolecules with alternating 1,2-pyrrolene and ethylidene units in the backbone with yields of 80, 44, and 33%, respectively. The polymers demonstrate paramagnetic and luminescent properties.     

Expanded Prussian blue analogues incorporating [Re6Se8(CN)6](3-/4-) clusters: adjusting porosity via charge balance

Face-capped octahedral [Re(6)Se(8)(CN)(6)](3-/4-) clusters are used in place of octahedral [M(CN)(6)](3-/4-) complexes for the synthesis of microporous Prussian blue type solids with adjustable porosity. The reaction between [Fe(H(2)O)(6)](3+) and [Re(6)Se(8)(CN)(6)](4-) in aqueous solution yields, upon heating, Fe(4)[Re(6)Se(8)(CN)(6)](3).36H(2)O (4). A single-crystal X-ray analysis confirms the structure of 4 to be a direct expansion of Prussian blue (Fe(4)[Fe(CN)(6)](3).14H(2)O), with [Re(6)Se(8)(CN)(6)](4-) clusters connected through octahedral Fe(3+) ions in a cubic three-dimensional framework. As in Prussian blue, one out of every four hexacyanide units is missing from the structure, creating sizable, water-filled cavities within the neutral framework. Oxidation of (Bu(4)N)(4)[Re(6)Se(8)(CN)(6)] (1) with iodine in methanol produces (Bu(4)N)(3)[Re(6)Se(8)(CN)(6)] (2), which is then metathesized to give the water-soluble salt Na(3)[Re(6)Se(8)(CN)(6)] (3). Reaction of [Co(H(2)O)(6)](2+) or [Ni(H(2)O)(6)](2+) with 3 in aqueous solution affords Co(3)[Re(6)Se(8)(CN)(6)](2).25H(2)O (5) or Ni(3)[Re(6)Se(8)(CN)(6)](2).33H(2)O (6). Powder X-ray diffraction data show these compounds to adopt structures based on the same cubic framework present in 4, but with one out of every three cluster hexacyanide units missing as a consequence of charge balance. In contrast, reaction of [Ga(H(2)O)(6)](3+) with 3 gives Ga[Re(6)Se(8)(CN)(6)].6H(2)O (7), wherein charge balance dictates a fully occupied cubic framework enclosing much smaller cavities. The expanded Prussian blue analogues 4-7 can be fully dehydrated, and retain their crystallinity with extended heating at 250 degrees C. Consistent with the trend in the frequency of framework vacancies, dinitrogen sorption isotherms show porosity to increase along the series of representative compounds 7, Ga(4)[Re(6)Se(8)(CN)(6)](3).38H(2)O, and 6. Furthermore, all of these phases display a significantly higher sorption capacity and surface area than observed in dehydrated Prussian blue. Despite incorporating paramagnetic [Re(6)Se(8)(CN)(6)](3-) clusters, no evidence for magnetic ordering in compound 6 is apparent at temperatures down to 5 K. Reactions related to those employed in preparing compounds 4-6, but carried out at lower pH, produce the isostructural phases H[cis-M(H(2)O)(2)][Re(6)Se(8)(CN)(6)].2H(2)O (M = Fe (8), Co (9), Ni (10)). The crystal structure of 8 reveals a densely packed three-dimensional framework in which [Re(6)Se(8)(CN)(6)](4-) clusters are interlinked through a combination of protons and Fe(3+) ions.     

A new cyanobridged one-dimensional coordination polymer based on the octahedral rhenium cluster [Re6Se8(CN)6]4−: Synthesis and crystal structure of [{Cu(H2O)0.5(en)2} {Cu(en)2}Re6Se8(CN)6]·3H2O

The rhenium cluster complex [{Cu(H₂O)_0.5(en)₂} {Cu(en)₂} Re₆Se₈(CN)₆]·3H₂O has been obtained by the reaction of an aqueous solution of K₄[Re₆Se₈(CN)₆]·3.5H₂O with an aqueous solution of Cu(en)₂Cl₂ using cross diffusion through a gel. The structure of the compound has been characterized by a single-crystal X-ray diffraction method (a = 10.690(3) Å, b = 15.035(5) Å, c = 25.847(8) Å, V = 4154(2) ų, Z = 4, space group P2₁2₁2₁, R = 0.0651). Cluster anions [Re₆Se₈(CN)₆]^4? in the complex are connected with Cu²⁺ cations by cyano bridges resulting in zigzag chains. Coordination environment of cations is completed by ethylenediamine molecules. Additionally each cluster anion is coordinated by one terminal fragment {Cu(H₂O)_0.5(en)₂}.     

New viologen analogs: 1,4-bis[2-(pyridin-4-yl)ethenyl]benzene quaternary salts

Alkylation of 1,4-bis[2-(pyridin-4-yl)ethenyl]benzene with alkyl p-toluenesulfonates and dimethyl sulfate gave new viologen analogs, 1-alkyl-4-(2-{4-[2-(1-alkylpyridinium-4-yl)ethenyl]phenyl}ethenyl)-pyridinium bis(p-toluenesulfonates) and sulfate. Their derivatives with tetrafluoroborate and tetraphenylborate ions were also obtained. Spectral properties of the synthesized compounds were examined, and their structure was determined by X-ray analysis.     

Primitive cubic packing of anions in Cs4[Re6Te8(CN)6]· 2H2O and Ba2[Re6Te8(CN)6] · 12H2O crystals

Crystal structures of Cs₄[Re₆Te₈(CN)₆]·2H₂O (1) and Ba₂[Re₆Te₈(CN)₆]· 12H₂O (2) are determined. Crystals 1 are orthorhombic, a = 14,282(1), b = 12.910(1), c = 18.040(1) Å, V_cell = 3326.3(8) ų, space group Pbcn, Z = 4, d_calc = 5.715 g/cm³, R(F) = 0.0482 for 3193 F_hkl > 4σ(F). Crystals 2 are triclinic, a = 9.671(3), b = 9.697(4), c = 11.039(4) Å, α = 89.86(3), β = 72.34(3), γ = 82.46(3)°, V_cell = 977.2(6) ų, space group P1, Z = 1, d^calc = 4.733 g/cm³, R(F) = 0.0490 for 3226 F_hkl > 4σ(F). In both structures, the [Re₆Te₈(CN)₆]^4? anions form a distorted primitive cubic packing with distances between the centers 9.02-9.63 Å in 1 and 9.70-11.04 Å in 2. The Cs⁺ cations in 1 lie near the face centers of the cubes formed by the onions. In 2, cation pairs (Ba²⁺)₂ bonded to two solvate water molecules are formed; the pairs lie at the centers of the anion cubes. In structures 1 and 2, there are shortened contacts between the tellurium atoms belonging to the neighboring anions (3.75-4.09 and 3.95-4.22 Å, respectively).     

Asymmetric addition of pyridine to 1,4-bis(ethynyl)bicyclo[2.2.2]octane: dissymmetrical rotator ligands illustrated in dpppPt(II) and [Re6Se8]2+ complexes and an amphidynamic hydrogen bonded framework solid

A polar function like pyridine increases the polarity difference between mono- and disubstituted 1,4-bis(trimethylsilylethynyl)bicyclo[2.2.2]octane cores allowing for their ready separation by chromatography, affording two dissymmetrical ligands illustrated in metal-rotor hybrids like a corner-shaped mononuclear complex, an octahedral hexanuclear metal complex, and a framework solid with a rather slow rotator.     

(EDT-TTF-CONH2)6[Re6Se8(CN)6], a metallic Kagome-type organic-inorganic hybrid compound: electronic instability, molecular motion, and charge localization

(EDT-TTF-CONH2)6[Re6Se8(CN)6], space group R, was prepared by electrocrystallization from the primary amide-functionalized ethylenedithiotetrathiafulvalene, EDT-TTF-CONH2 (E(1/2)1 = 0.49 V vs SCE in CH3CN), and the molecular cluster tetraanion, [Re6Se8(CN)6]4- (E(1/2) = 0.33 V vs SCE in CH3CN), equipped with hydrogen bond donor and hydrogen bond acceptor functionalities, respectively. Its Kagome topology is unprecedented for any TTF-based materials. The metallic state observed at room temperature has a strong two-dimensional character, in coherence with the Kagome lattice symmetry, and the presence of minute amounts of [Re6Se8(CN)6](3-)* identified by electron spin spectroscopy. A structural instability toward a distorted form of the Kagome topology of lesser symmetry is observed at ca. 180 K. The low-temperature structure is associated with a localized, electrically insulating electronic ground state and its magnetic susceptibility accounted for by a model of uniform chains of localized S = 1/2 spins in agreement with the 100 K triclinic crystal structure and band structure calculations. A sliding motion, within one out of the three (EDT-TTF-CONH2)2 dimers coupled to the [Re6Se8(CN6)(3-)*]/[Re6Se8(CN6)4-] proportion at any temperature, and the electronic ground state of the organic-inorganic hybrid material are analyzed on the basis of ESR, dc conductivity, 1H spin-lattice relaxation, and static susceptibility data which qualify a Mott localization in [EDT-TTF-CONH2]6[Re6Se8(CN)6]. The coupling between the metal-insulator transition and a structural transition allows for the lifting of a degeneracy due to the ternary axis in the high temperature, strongly correlated metallic phase which, in turn, leads to Heisenberg chains at low temperature.     

Synthesis and Fluorescence of alt-Copoly[1, 4-divinylenebenzene／1, 4-bis（dimethylsilylene）benzene]

Silicon inserted n conjugated copolymer was synthesized by Heck reaction with moderate molecular weight. This silicon containing copolymer is thermally stable to 400℃, while emission of this polymer is blue-shifted compared with polyphenylenevinylene greenish emission. It shows potential application as organic emitter in OLED.     

Synthesis of aromatic polyethers by Scholl reaction. V. Synthesis and polymerization of 1,3-bis[4-(1-naphthoxy) benzoyl]benzene, 1,4-bis[4-(1-naphthoxy)benzoyl]benzene,bis[4-(1-naphthoxy)phenyl]methane, 1,3-bis[4-(1-naphthoxy) phenylmethyl]benzene,and 1,4-bis-[4-(1-naphthoxy)phenylmethyl]benzene

This article describes the synthesis and the cation-radical polymerization (Scholl reaction) of 1,3-bis[4-(1-naphthoxy) benzoyl] benzene ( 6 ) and 1,4-bis[4-(1-naphthoxy) benzoyl]- benzene ( 7 ) initiated by FeCI₃. This polymerization produced poly(ether ether ketone ketone)s (PEEKK) of number average molecular weight (M?_n) up to 5400 g/mol. The synthesis of bis[4-(1-naphthoxy) phenyl] methane ( 8 ), 1,3-bis[4-(1-napthoxy) phenylmethyl] benzene ( 9 ), and 1,4-bis[4-(1-naphthoxy) phenylmethyl] benzene ( 10 ) are also described. Polyethers of M?_n up to 15400 g/mol at a FeCl₃/monomer molar ratio of 2/1 were obtained. An increased polymerizability of the monomers 9 and 10 containing two CH₂ groups versus that of the corresponding monomers containing two carbonyl groups ( 6 and 7 ) was observed. This enhanced polymerizability was explained based on the increased nucleophilicity of monomers 9 and 10 .     

Synthesis and crystal structure of the octahedral cluster complex [Th(DMSO)8Cl][Re6Se7Cl7]

A cluster complex of the composition [Th(DMSO)₈Cl][Re₆Se₇Cl₇] has been obtained by interaction of ThCl₄ solution in DMSO with a water solution of K₃[Re₆Se₇Cl₇] and KCl. The compound crystallizes in the rhombic space group Pbcm with unit cell parameters a = 12.262(2) Å, b = 19.653(6) Å, c = 23.603(6) Å, V = 5688(2) ų, Z = 4, d _calc = 3.282 g/cm³. The structure is built from centrosymmetric cluster anions [Re₆Se₇Cl₇]^3? and complex cations [Th(DMSO)₈Cl]³⁺ possessing mirror-plane symmetry, half of the DMSO ligands being doubly disordered.     

Interpenetrating frameworks in the structure of the [(SnMe3)3Re6Se8(CN)6] cluster complex

Single-crystal X-ray diffraction is used to determine the structure of a new compound based on an octahedral cyanide anionic cluster complex of rhenium and a trimethyltin(IV) cation: {(SnMe₃)₃[Re₆Se₈(CN)₆]} (1). The crystallographic characteristics: space group C2/c, a = 13.9898(14) Å, b =15.334(2) Å, c = 20.761(2) Å, β = 97.75(0)°, V = 4412.91(90) ų, Z = 4, d _x = 3.607 g/cm³, and R = 0.0526. The compound has a framework structure; two porous frameworks with pcu topology interpenetrate each other.