Reactions of [M(MeCN) n ][BF 4 ] 2 salts with Bu 4 N(TCNQ) in MeOH yield M(TCNQ) 2 (MeOH) x (M ) Mn, 1; Fe, 2; Co, 3; Ni, 4, x ) 2-4), and reactions of MnCl 2 , FeSO 4 ‚7H 2 O, CoSO 4 ‚7H 2 O and NiCl 2 ‚6H 2 O in H 2 O produce M(TCNQ) 2 (H 2 O) 2 (M ) Mn, 5; Fe, 6; Co, 7; Ni, 8). Infrared spectroscopy, powder X-ray diffraction and thermogravimetric analyses of 1-8 indicate that the products prepared in the same solvent constitute isostructural families of compounds.[Mn(TCNQ-TCNQ)(MeOH) 4 ] ∞ (9) crystallizes in the triclinic space group P1 h, a ) 7.2966( 8Compound 9 contains TCNQligands that have undergone an unusual σ-dimerization to [TCNQ-TCNQ] 2that acts as a tetradentate ligand to Mn(II) ions to give a 2-D staircase polymeric motif. The layers are connected by hydrogenbonds between axially coordinated MeOH from adjacent layers and MeOH located between the layers. Compound 10 exhibits a zigzag polymeric motif with equatorially bound TCNQderived ligands of two types; the edges of the layers consist of cis-µ-TCNQmolecules involved in π-stacking with TCNQunits from another layer and σ-[TCNQ-TCNQ] 2acting as a tetradentate bridging ligand. Axial MeOH ligands are hydrogen-bonded to dangling nitrile groups of cis-µ-TCNQligands in the next layer. Mn(TCNQ) 2 (H 2 O) 2 (11) crystallizes in the monoclinic space group I2/a, a ) 12.5843(7) Å, b ) 13.7147(7) Å, c ) 13.3525(70 Å, β ) 92.887(1)°, V ) 2301.58 Å 3 , Z ) 4. This material adopts a double-layer motif consisting of Mn(II) ions bonded to syn-µ 2 -TCNQequatorial ligands and axial H 2 O molecules. Compounds 1-11 exhibit Curie-Weiss behavior with weak antiferromagnetic coupling being observed at low temperatures. The Zn(II) analogue of 10, [Zn(TCNQ)(TCNQ-TCNQ) 0.5 (MeOH) 2 ] ∞ (12) was also prepared: space group C2/c, a ) 14.2252(1) Å, b ) 27.3290(4) Å, c ) 13.1177(2) Å, β ) 90.074(1)°, V ) 5099.64(11) Å 3 , Z ) 8. Powder X-ray diffraction was used to probe structures 1-11, and it was found that 9 converts to a new phase with heating or exposure to X-rays that is related to disruption of the σ-dimer (TCNQ-TCNQ) 2ligands and loss of MeOH. The new phase, whose powder pattern is identical with that of a phase prepared from MeCN, exhibits ferromagnetic behavior.
Reaction of disodium tetracarbonylferrate, Na2[Fe(CO)4], with [2,6-bis(2,4,6-triisopropylphenyl)phenyl]gallium dichloride, (Mes*2C6H3)GaCl2 (Mes* = 2,4,6-triisopropylphenyl), affords tetracarbonyliron [2,6-bis(2,4,6-triisopropylphenyl)phenyl]gallyne, (CO)4Fe⋮Ga(C6H3Mes*2), as anaerobically stable yellow prism crystals. The title compound offers evidence in support of an iron−gallium triple bondthe first ferrogallyne.
1,3,5-Tris(4-carboxyphenyl)benzene assembles into an intricate 8-fold polycatenated assembly of (6,3) hexagonal nets formed through hydrogen bonds and π-stacking. One polymorph features 56 independent molecules in the asymmetric unit, the largest Z' reported to date. The framework is permanently porous, with a BET surface area of 1095 m(2) g(-1) and readily adsorbs N2, H2 and CO2.
The reaction of [P 2 W 15 O 56 ] 12-and aqueous Fe 3+ forms two ferric polytungstophosphate derivatives that have been isolated, purified, and characterized by X-ray crystallography and several physical methods. At pH ∼3 and [Na + ] ) 2 M, needles of Na 12 [Fe III 4 (H 2 O) 2 (P 2 W 15 O 56 ) 2 ]‚58H 2 O, Na-1, form, in which the conventional ion packing arrangement in solid heteropoly acids is observed: each polyanion, [Fe III 4 (H 2 O) 2 (P 2 W 15 O 56 ) 2 ] 12-(1), is well separated by the cations (Na + ). At pH ∼1 and [Na + ] ) 1 M, however, elongated prisms of H 3 Na 9 [Fe III 4 (H 2 O) 2 -(P 2 W 15 O 56 ) 2 ]‚62H 2 O, (Na-1) n , form. (Na-1) n is a novel one-dimensional inorganic polymer composed of 1 linked via ion pairing with strongly associated hydrated sodium cations. Both Na-1 and (Na-1) n display identical characteristics in H 2 O solution. Seven lines of evidence are consistent with the Fe III 4 oxidation state in 1: (1) the synthesis itself (only Fe 3+ used); (2) bond-length-based valence sum calculations based on the two X-ray structures;(3) the electrochemical behavior; (4) the charge requirements and elemental analyses; (5) no reaction between 1 and Ce 4+ ; (6) the lack of a Jahn-Teller distortion; and (7) the infrared spectrum relative to those of the literature [M 4 (H 2 O) 2 (P 2 W 15 O 56 ) 2 ] 16-sandwich compounds, where M ) a divalent first-row transition metal ion in all cases. The tetra-n-butylammonium salt of 1, TBA-1, exhibits catalytic activity for oxidation of alkenes by H 2 O 2 . The catalytic effect is substantial. For example, in the reaction of cyclohexene + H 2 O 2 , rate(with TBA-1)/rate(without TBA-1) (-d[cyclohexene]/dt) is ∼25. Alkene oxidation is characterized predominantly by allylic attack on aliphatic substrates and oxidative cleavage of stilbenes. The polyanion, 1, is quite stable under catalytic conditions (no decomposition of 1 was detected by 31 P NMR after a solution of 1, alkene, and 0.25 M H 2 O 2 was incubated for 48 h).
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