Nanoscale assemblies of gigantic molecular {Mo154}-rings: (dimethyldioctadecylammonium)20[Mo154O462H8(H2O)70

Clusters based on the mixed-valence gigantic inorganic ring [Mo154O462H14(H2O)70]14- ({Mo154}-ring) and dimethyldioctadecylammonium (DODA) were combined to form novel molecular assemblies of an inorganic-organic hybrid molecular system as Langmuir-Blodgett (LB) and cast films. (DODA)20[Mo154O462H8(H2O)70] (2) was prepared by cation exchange and was characterized by a combination of thermogravimetry, IR, UV-vis-NIR, 1H NMR, and XRD measurements. The salt 2 was soluble in common organic solvents, and the chemical stability of {Mo154}-ring encapsulated by DODA cationic surfactants in CHCl3 was found to be higher than that of the "native" sodium salt of the {Mo154}-ring in H2O. Uniform spherical vesicle-like molecular assemblies of (DODA)20[Mo154O462H8(H2O)70] were observed in dilute THF, whose average diameter of 95 nm and a normalized variance of 5.7% were confirmed by a X-ray small-angle scattering. Deposition of 2 as a cast film showed circular domains with a typical diameter of approximately 100 nm, indicating possible similarities between solution and surface-deposited structures. The resulting LB films of salt 2 were transferred from an acidic buffer subphase with pH = 1.5 onto mica, giving a two-dimensional film surface with a unity transfer ratio. Further, the electronic absorption spectra of the LB multilayer were consistent with the classic type II mixed-valence MoV/MoVI electronic state well know for molybdenum blue {Mo154}-ring systems, and it appears that on the surface the plane of the {Mo154}-ring is approximately parallel to the substrate surface, as indicated by polarized electronic spectra, while the alkyl chains of DODA were relatively normal to the substrate surface. Therefore, the layer between the {Mo154}-rings and DODA cations was alternately stacked along the direction of film propagation. Finally, it was found that the surface morphology of the cast and LB films was determined by the molecular assembly of (DODA)20[Mo154O462H8(H2O)70] in solution and the air-water interface, respectively.     

Surfactant-encapsulated clusters (SECs): (DODA)20(NH4)[H3Mo57V6(NO)6O183(H2O)18], a case study

We present a comprehensive study of the partially reduced polyoxomolybdate [H3-Mo57V6(NO)6O183(H2O)18]21-encapsulated in a shell of dimethyldioctadecylammonium (DODA) surfacmolecules. Treatment of an aqueous solution of (NH4)21[H3Mo57V6-(NO)6O183(H2O)18] . 65H2O (1a) with a trichloromethane solution of the surfactant leads to instant transfer of the encapsulated complex anion into the organic phase. Results from vibrational spectroscopy. analytical ultracentrifugation, small-angle X-ray scattering, transmission electron microscopy, elemental analysis, and Langmuir compression isotherms are consistent with a single polyoxometalate core encapsulated within a shell of 20 DODA molecules. The molar mass of the supramolecular assembly is 20249 gmol(-1) and the diameter is 3.5 nm. A material with the empirical formula (DODA)20(NH4)[H3-Mo57V6NO)6O183(H2O)18] (2) was isolated as a dark violet solid, which readily dissolves in organic solvents. Slow evaporation of solutions of 2 on solid substrates forces the hydrophobic particles to aggregate into a cubic lattice. Annealing these so-formed films at elevated temperature causes de-wetting with terrace formation similar to liquid crystals and block copolymers. Compound 2 forms a stable Langmuir monolayer at the air-water interface; Langmuir-Blodgett multilayers are readily prepared by repeated transfer of monolayers on solid substrates. The films were characterized by optical ellipsometry, Brewster angle microscopy, transmission electron microscopy, and X-ray reflectance.     

Preparation and Crystal Structure of Hetero-metal Clusters [h5-C5H4C(O)CH2CH2C(O)OCH3]FeCoM(m3-S)(CO)8 (M = Mo or W)

The hetero-metal clusters [h5-C5H4C(O)CH2CH2C(O)OCH3]FeCoM(m3-S)(CO)8 (M = Mo 1, M = W 2) were prepared by thermal reactions of FeCo2(CO)9(m3-S) with metal exchange reagent [h5-C5H4C(O)CH2CH2C(O)OCH3]M(CO)3Na (M = Mo or W) in THF. Cluster 1 reacted with 2,4-dinitrophenylhydrazine at room temperature to yield the cluster hydrazone derivative (m3-S)CoFeMo(CO)8[h5-C5H4C(NR)Me] [R = NHC6H3-2,4-(NO2)2] 3. All the compounds were characterized by elemental analyses, IR and NMR spectra. Cluster 1 was determined by single crystal X-ray diffraction. Crystal data: C18H11O11SCoFeMo, Mr = 646.05, triclinic, space group P_1, a = 8.148(2), b = 10.685(3), c = 13.410(4) ?, a = 100.077(5), b = 102.452(5), g = 91.108(6)°, V = 1120.4(5) ?3, Z = 2, Dc = 1.915 g/cm3, F(000) = 636, m = 2.071 mm-1, the final R = 0.0378 and wR = 0.0968 for 5074 observations with (I > 2s(I)).     

The hydrothermal syntheses and characterization of one- and two-dimensional structures constructed from metal-organic derivatives of polyoxometalates: [(Cu(bpy)2)(Cu(bpy)(H2O))(Mo5O15)(O3P(CH2)4PO3)].H2O and [(u2(tpypyz)(H2O)2)(Mo5O15)(O3PCH2CH2PO3)].5.5H2O [bpy = 2,2'-bipyridine,tpypyz = tetra(2-pyridyl)pyrazine

The hydrothermal reaction of CuSO(4).5H2O, Na2MoO(4).2H2O and 2,2'-bipyridine with the bridging diphosphonate ligand H2O3P(CH2)4PO3H2 yields the one-dimensional chain [(Cu(bpy)2)(Cu(bpy)(H2O)2)(Mo5O15)(O3P(CH2)4PO3)].H2O; the introduction of a second bridging component in the reaction of Cu(MeCO2)2.H2O, MoO3, H2O3PCH2CH2PO3H2 and tetra(2-pyridyl)pyrazine yields the network solid [(Cu2(tpypyz)(H2O)2)(Mo5O15)(O3PCH2CH2PO3)].5.5H2O.     

Photoreductive self-assembly from [Mo7O24]6- to carboxylates-coordinated {Mo142} Mo-blue nanoring in the presence of carboxylic acids

The primary steps of the photoredox reaction between [Mo7O24]6- and carboxylic acid electron (and proton) donors in aqueous solutions are investigated by the chemically induced dynamic electron spin polarization (CIDEP) spectroscopy. The excitation of the O-->Mo ligand-to-metal charge-transfer (LMCT) bands of [Mo7O24]6- in the presence of CH3CO2H induces the emissive electron spin polarization (ESP) of *CH2CO2 and *CH3 radicals with an accompanying formation of the one-electron reduced species [Mo7O23(OH)]6-, which is demonstrated by the triplet mechanism involving the O --> Mo LMCT triplet states. The prolonged photolysis of the solution containing [Mo7O24]6- and CH3CO2H at pH = 3.4 leads to the formation of the acetate/propionate-coordinated {Mo142} Mo-blue nanoring, [MoV28MoV(I)114O429H10(H2O)(49)(CH3)CO2 triple bond Ac5(C2H5CO2 triple bond Pr)]30- (1a) through the formation of the cis-configured dimeric dehydrative condensation to two-electron reduced Mo-blue [(Mo7O23)2]10- ({Mo14}). 1a is isolated as a [NH4]+/[Me3NH]+-mixed salt which is formulated as [NH4]27[Me3NH]3[Mo(V)28Mo(VI)114O429H10(H2O)49(CH3CO2)5(C2H5CO2)].150 +/- 10H2O (1) by results of elementary analysis, single-crystal X-ray analysis, 1H NMR, IR, and UV/Vis measurements, and manganometric redox titration. Based on the building-block sequence of for 1a, the bottom-up processes from [Mo7O24]6- to the {Mo142} ring in the coexistence of beta-[Mo8O26]4- are discussed by (i) the stabilization of the molecular curvature of {Mo14} through both the intramolecular transfer of monomolybdates and the intermolecular transfer of monomolybdates as degradation fragments of beta-[Mo8O26]4-, to yield {Mo21} and {Mo20} building blocks, (ii) the outer-ring formation resulting from seven successive two-electron-photoreductive condensations among {Mo21} and {Mo20}, and (iii) inner-ring formation resulting from eight successive dehydrative condensations between monomolybdate linkers attached to the neighboring head Mo sites.     

Synthesis and characterization of a twin Cubane-type molybdenum-rhodium-sulfur cluster, [{Mo3RhCp*S4(H2O)7(O)}2]8+. X-ray structure of [{Mo3RhCpS4(H2O7O}2](CH3C6H4SO3)(8).14H2O

The reaction of [Mo(3)S(4)(H(2)O)(9)](4+) (1) with [(CpRhCl(2))(2)] afforded a novel rhodium-molybdenum cluster, [{Mo(3)RhCpS(4)(H(2)O)(7)(O)}(2)](8+) (2). X-ray structure analysis of [2](pts)(8).14H(2)O (pts(-) = CH(3)C(6)H(4)SO(3)(-)) has revealed the existence of a new oxo-bridged twin cubane-type core, (Mo(3)RhCpS(4))(2)(O)(2). The high affinity of the CpRh group for sulfur atoms in 1 seems to be the main driving force for this reaction. The strong Lewis acidity of the CpRh group in intermediate A, [Mo(3)RhCpS(4)(H(2)O)(9)](6+), caused a release of proton from one of the water molecules attached to the molybdenum atoms to give intermediate B, [Mo(3)RhCpS(4)(H(2)O)(8)(OH)](5+). The elimination of two water molecules from two intermediate B molecules, followed by the deprotonation reaction of hydroxo bridges, generated the twin cubane-type cluster 2. The formal oxidation states of rhodium and molybdenum atoms are the same before and after the reaction (i.e., Mo(IV)(3), Rh(III)). The Mo-O-Mo moieties in [2](pts)(8).14H(2)O are nearly linear with a bond angle of 164.3(3) degrees, and the basicity of the bridging oxygen atoms seems to be weak. For this reason, protonation at the bridging oxygen atoms does not occur even in a strongly acidic aqueous solution. The binding energy values of Mo 3d(5/2), Rh 3d(5/2), and C 1s obtained from X-ray photoelectron spectroscopy measurements for [2](pts)(8).14H(2)O are 229.8, 309.3, and 285 eV, respectively. The XPS measurements on the Rh 3d(5/2) binding energy indicate that the oxidation state of Rh is 3+. The binding energy of Mo 3d(5/2) (229.8 eV) compares with that observed for [1](pts)(4).7H(2)O (230.7 eV, Mo 3d(5/2)). A lower energy shift (0.9 eV) is observed in the binding energy of Mo 3d(5/2) for [2](pts)(8).14H(2)O. This energy shift may correspond to the coordination of an oxygen atom having a negative charge to the molybdenum atom.     

Hydricities of BzNADH, CH5Mo(PMe3)(CO)2H, and C5Me5Mo(PMe3)(CO)2H in acetonitrile

The thermodynamic hydride donor abilities of 1-benzyl-1,4-dihydronicotinamide (BzNADH, 59 +/- 2 kcal/mol), C(5)H(5)Mo(PMe(3))(CO)(2)H (55 +/- 3 kcal/mol), and C(5)Me(5)Mo(PMe(3))(CO)(2)H (58 +/- 2 kcal/mol) have been measured in acetonitrile by calorimetric and/or equilibrium methods. The hydride donor abilities of BzNADH and C(5)H(5)Mo(PMe(3))(CO)(2)H differ by 13 and 24 kcal/mol, respectively, from those reported previously for these compounds in acetonitrile. These results require significant revisions of the hydricities reported for related NADH analogues and metal hydrides. These compounds are moderate hydride donors as compared to previously determined compounds.     

Synthesis and Crystal Structure of an Incomplete Cubane-type Mo3S4 Cluster with the N-N-O Type Tridentate Ligand:{Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)·(H2O)2·(DMF)

A new cluster {Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)·(H2O)2·(DMF) (DTP = diethyldithiophosphate) has been synthesized via ligand substitution reaction of Mo3S4(DTP)4(H2O) with an alkaline ligand 1,3-diamino-2-propanol(DAPROH) in a mixed organic solvent, and its crys- tal structure was determined with the following data: Mo3S6PC16H48O8N7, Mr = 977.76, triclinic, space group P, Z = 2, a = 10.319(2), b = 12.843(3), c = 15.335(3)(A), α = 65.26(3), β = 82.18(3), γ = 70.67(3)o, V = 1741.7(6) (A)3, Dc = 1.864 g/cm3, μ = 1.517 mm-1, F(000) = 988, the final R = 0.0794 and wR = 0.2111 for 6318 observed reflections (I>2σ(I)). The structure analysis indicates that all DTP ligands of Mo3S4(DTP)4(H2O) are replaced and each DAPRO molecule acts as a tri- dentate ligand chelating to each Mo atom of the Mo3S4 core. Different from the precursor, the clus- ter symmetry is elevated to C3. In addition, the UV-spectrum of the title compound was measured.     

Syntheses,reactivity, and crystal structures of molybdenum complexes with pyridine-2-thionate (pyS)-containing ligands: crystal structures of [Mo(eta(3)-C(3)H(5))(CO)(2)](2)(mu-eta(1),eta(2)-pyS)(2), exo-[Mo(eta(3)-C(3)H(5))(CO)(eta(2)-pyS)(eta(2)-dppe)], [Mo(CO)(3)(eta(1)-SC(5)H(4)NH)(eta(2)-dppm)], and [Mo(CO)(eta(2)-pyS)(2)(eta(2)-dppm)

The doubly bridged pyridine-2-thionate (pyS) dimolybdenum complex [Mo(eta(3)-C(3)H(5))(CO)(2)](2)(mu-eta(1),eta(2)-pyS)(2) (1) is accessible by the reaction of [Mo(eta(3)-C(3)H(5))(CO)(2)(CH(3)CN)(2)Br] with pySK in methanol at room temperature. Complex 1 reacts with piperidine in acetonitrile to give the complex [Mo(eta(3)-C(3)H(5))(CO)(2)(eta(2)-pyS)(C(5)H(10)NH)] (2). Treatment of 1 with 1,10-phenanthroline (phen) results in the formation of complex [Mo(eta(3)-C(3)H(5))(CO)(2)(eta(1)-pyS)(phen)] (3), in which the pyS ligand is coordinated to Mo through the sulfur atom. Four conformational isomers, endo,exo-complexes [Mo(eta(3)-C(3)H(5))(CO)(eta(2)-pyS)(eta(2)-diphos)] (diphos = dppm, 4a-4d; dppe, 5a-5d), are accessible by the reactions of 1 with dppm and dppe in refluxing acetonitrile. Homonuclear shift-correlated 2-D (31)P((1)H)-(31)P((1)H) NMR experiments of the mixtures 4a-4d have been employed to elucidate the four stereoisomers. The reaction of 4 and pySK or [Mo(CO)(3)(eta(1)-SC(5)H(4)NH)(eta(2)-dppm)] (6) and O(2) affords allyl-displaced seven-coordinate bis(pyridine-2-thionate) complex [Mo(CO)(eta(2)-pyS)(2)(eta(2)-dppm)] (7). All of the complexes are identified by spectroscopic methods, and complexes 1, 5d, 6, and 7 are determined by single-crystal X-ray diffraction. Complexes 1 and 5d crystallize in the orthorhombic space groups Pbcn and Pbca with Z = 4 and 8, respectively, whereas 6 belongs to the monoclinic space group C2/c with Z = 8 and 7 belongs to the triclinic space group Ponemacr; with Z = 2. The cell dimensions are as follows: for 1, a = 8.3128(1) A, b = 16.1704(2) A, c = 16.6140(2) A; for 5d, a = 17.8309(10) A, b = 17.3324(10) A, c = 20.3716(11) A; for 6, a = 18.618(4) A, b = 16.062(2) A, c = 27.456(6) A, beta = 96.31(3) degrees; for 7, a = 9.1660(2) A, b = 12.0854(3) A, c = 15.9478(4) A, alpha = 78.4811(10) degrees, beta = 80.3894(10) degrees, gamma = 68.7089(11) degrees.     

Novel acetate polyoxomolybdate "host" accommodating a zigzag-chainlike "guest" of five edge-shared sodium cations: Na(21)[[Na(5)(H(2)O)(14)]within[Mo(46)O(134)(OH)(10)(mu-CH(3)COO)(4)]].CH(3)COONa. approximately equal to 95H(2)O

A novel ESR-silent polyoxomolybdate Na(21)([Na(5)(H(2)O)(14)][Mo(46)O(134)(OH)(10)(mu-CH(3)COO)(4)]).CH(3)COONa.approximately equal to 90H(2)O (3) was simply synthesized in high yield by reducing an acidified aqueous solution of Na(2)MoO(4).2H(2)O and CH(3)COONa.3H(2)O. The structure of 3 is constructed by a 46-member crown-shaped anion, [Na(5)(H(2)O)(14)]within[Mo(V)(20)Mo(VI)(26)O(134)(OH)(10)(mu-CH(3)COO)(4)](21-), 3a, which is built up by three different but related building blocks in a new mode and further connected into layers via Na(+) and hydrogen bonds. Crystal data of compound 3: triclinic space group P(-1); a = 16.4065(3), b = 17.4236(2), c = 20.8247(3) A; alpha= 87.57, beta= 67.9810(10), gamma= 80.6970(10)o; V = 5445.08(14) A(3); Z = 1; D(calcd) = 2.902. Structure solution and refinement are based on 19014 reflections, R = 0.0750.     

Reaction of Mo(CO)6 with Alkoxide: Synthesis and Structure of the Mo(0)-OR Complex [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2C6H5)3]

The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a=15.359(2), b=18.378(3), c=24.952(2)(A), β=102.268(4)°, V=6882.3(16) (A)3, Mr=1348.34, Z=4, Dc=1.301 g/cm3, F(000)=2832 and μ= 0.424 mm-1. The final R=0.0606 and wR=0.1552 for 9396 observed reflections (Ⅰ ＞ 2σ(Ⅰ)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) (A), indicating no metalmetal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.     

Substitution reactions of [Ru(dppe)(CO)(H(2)O)(3)][OTf](2)

The labile nature of the coordinated water ligands in the organometallic aqua complex [Ru(dppe)(CO)(H(2)O)(3)][OTf](2) (1) (dppe = Ph(2)PCH(2)CH(2)PPh(2); OTf = OSO(2)CF(3)) has been investigated through substitution reactions with a range of incoming ligands. Dissolution of 1 in acetonitrile or dimethyl sulfoxide results in the facile displacement of all three waters to give [Ru(dppe)(CO)(CH(3)CN)(3)][OTf](2) (2) and [Ru(dppe)(CO)(DMSO)(3)][OTf](2) (3), respectively. Similarly, 1 reacts with Me(3)CNC to afford [Ru(dppe)(CO)(CNCMe(3))(3)][OTf](2) (4). Addition of 1 equiv of 2,2'-bipyridyl (bpy) or 4,4'-dimethyl-2,2'-bipyridyl (Me(2)bpy) to acetone/water solutions of 1 initially yields [Ru(dppe)(CO)(H(2)O)(bpy)][OTf](2) (5a) and [Ru(dppe)(CO)(H(2)O)(Me(2)bpy)][OTf](2) (6a), in which the coordinated water lies trans to CO. Compounds 5a and 6a rapidly rearrange to isomeric species (5b, 6b) in which the ligated water is trans to dppe. Further reactivity has been demonstrated for 6b, which, upon dissolution in CDCl(3), loses water and coordinates a triflate anion to afford [Ru(dppe)(CO)(OTf)(Me(2)bpy)][OTf] (7). Reaction of 1 with CH(3)CH(2)CH(2)SH gives the dinuclear bridging thiolate complex [[(dppe)Ru(CO)](2)(mu-SCH(2)CH(2)CH(3))(3)][OTf] (8). The reaction of 1 with CO in acetone/water is slow and yields the cationic hydride complex [Ru(dppe)(CO)(3)H][OTf] (9) via a water gas shift reaction. Moreover, the same mechanism can also be used to account for the previously reported synthesis of 1 upon reaction of Ru(dppe)(CO)(2)(OTf)(2) with water (Organometallics 1999, 18, 4068).     

A building block approach to the synthesis of organic-inorganic oxide materials: the hydrothermal synthesis and network structure of [[Ni4(tpypyz)3][Mo5O15(O3PCH2CH2PO3)]2] x 23H2O (tpypyz = tetra-2-pyridylpyrazine)

The hydrothermal reaction of MoO3, [Ni(CH3CO2)2] x 4H2O, tpypyz, ethylenediphosphonic acid and water yields the 2D material [[Ni4(tpypyz)3][Mo5O15(O3PCH2CH2PO3)]2] x 23H2O (1 x 23H2O), constructed from [Mo5O15(O3PCH2CH2PO3)]4- clusters linked in one-dimension through the ethylene tethers of the diphosphonate component; these molybdodiphosphonate chains are in turn linked into a 2D network through the tetranuclear secondary metal-ligand subunit [Ni4(tpypyz)3]8+.     

Characterization of supramolecular (H2O)18 water morphology and water-methanol (H2O)15(CH3OH)3 clusters in a novel phosphorus functionalized trimeric amino acid host

Phosphorus functionalized trimeric alanine compounds (l)- and (d)-P(CH(2)NHCH(CH(3))COOH)(3) 2 are prepared in 90% yields by the Mannich reaction of Tris(hydroxymethyl)phosphine 1 with (l)- or (d)- Alanine in aqueous media. The hydration properties of (l)-2 and (d)-2 in water and water-methanol mixtures are described. The crystal structure analysis of (l)-2.4H(2)O, reveals that the alanine molecules pack to form two-dimensional bilayers running parallel to (001). The layered structural motif depicts two closely packed monolayers of 2 each oriented with its phosphorus atoms projected at the center of the bilayer and adjacent monolayers are held together by hydrogen bonds between amine and carboxylate groups. The water bilayers are juxtaposed with the H-bonded alanine trimers leading to 18-membered (H(2)O)(18) water rings. Exposure of aqueous solution of (l)-2 and (d)-2 to methanol vapors resulted in closely packed (l)-2 and (d)-2 solvated with mixed water-methanol (H(2)O)(15)(CH(3)OH)(3) clusters. The O-O distances in the mixed methanol-water clusters of (l)-2.3H(2)O.CH(3)OH and (d)-2.3H(2)O.CH(3)OH (O-O(average) = 2.857 A) are nearly identical to the O-O distance observed in the supramolecular (H(2)O)(18) water structure (O-O(average) = 2.859 A) implying the retention of the hydrogen bonded structure in water despite the accommodation of hydrophobic methanol groups within the supramolecular (H(2)O)(15)(CH(3)OH)(3) framework. The O-O distances in (l)-2.3H(2)O.CH(3)OH and (d)-2.3H(2)O.CH(3)OH and in (H(2)O)(18) are very close to the O-O distance reported for liquid water (2.85 A).     

Photolysis of CH3C(O)CH3 (248 nm, 266 nm), CH3C(O)C2H5 (248 nm) and CH3C(O)Br (248 nm): pressure dependent quantum yields of CH3 formation

The formation of CH(3) in the 248 or 266 nm photolysis of acetone (CH(3)C(O)CH(3)), 2-butanone (methylethylketone, MEK, CH(3)C(O)C(2)H(5)) and acetyl bromide (CH(3)C(O)Br) was examined using the pulsed photolytic generation of the radical and its detection by transient absorption spectroscopy at 216.4 nm. Experiments were carried out at room temperature (298 +/- 3 K) and at pressures between approximately 5 and 1500 Torr N(2). Quantum yields for CH(3) formation were derived relative to CH(3)I photolysis at the same wavelength in back-to-back experiments. For acetone at 248 nm, the yield of CH(3) was greater than unity at low pressures (1.42 +/- 0.15 extrapolated to zero pressure) confirming that a substantial fraction of the CH(3)CO co-product can dissociate to CH(3) + CO under these conditions. At pressures close to atmospheric the quantum yield approached unity, indicative of almost complete collisional relaxation of the CH(3)CO radical. Measurements of increasing CH(3)CO yield with pressure confirmed this. Contrasting results were obtained at 266 nm, where the yields of CH(3) (and CH(3)CO) were close to unity (0.93 +/- 0.1) and independent of pressure, strongly suggesting that nascent CH(3)CO is insufficiently activated to decompose on the time scales of these experiments at 298 K. In the 248 nm photolysis of CH(3)C(O)Br, CH(3) was observed with a pressure independent quantum yield of 0.92 +/- 0.1 and CH(3)CO remained below the detection limit, suggesting that CH(3)CO generated from CH(3)COBr photolysis at 248 nm is too highly activated to be quenched by collision. Similar to CH(3)C(O)CH(3), the photolysis of CH(3)C(O)C(2)H(5) at 248 nm revealed pressure dependent yields of CH(3), decreasing from 0.45 at zero pressure to 0.19 at pressures greater than 1000 Torr with a concomitant increase in the CH(3)CO yield. As part of this study, the absorption cross section of CH(3) at 216.4 nm (instrumental resolution of 0.5 nm) was measured to be (4.27 +/- 0.2) x 10(-17) cm(2) molecule(-1) and that of C(2)H(5) at 222 nm was (2.5 +/- 0.6) x 10(-18) cm(2) molecule(-1). An absorption spectrum of gas-phase CH(3)C(O)Br (210-305 nm) is also reported for the first time.     

Weakly coordinating anions HA2-generated from oxoanions A- and their conjugate acids. Coordination equilibria,ionic conductivities,and the structures of [Cu2(H(CH3SO3)2)4]n and [Cu(CO)(H(CF3CO2)2)]2

The coordination or ion pairing of the hydrogen-bonded anions H(CF3CO2)2- and H(CH3SO3)2- to NEt4+, Li+, Cu+, and/or Cu2+ was investigated. The structure of [Cu2(H(CH3SO3)2)4]n consists of centrosymmetric dimeric moieties that contain two homoconjugated (CH3SO2O-H...OSO2CH3)- anions per Cu2+ ion, forming typical Jahn-Teller tetragonally elongated CuO6 coordination spheres. The oxygen atoms involved in the nearly linear O-H...O hydrogen bonds (O...O approximately 2.62 A) are not coordinated to the Cu2+ ions. The structure of Cu2(CO)2(H(CF3-CO2)2)2 consists of pseudo-C2-symmetric dimers that contain one homoconjugated (CF3COO-H...OCOCF3)- anion per Cu+ ion, forming highly distorted tetrahedral Cu(CO)O3 coordination spheres. Three of the four oxygen atoms in each hydrogen-bonded H(CF3CO2)2- anion are coordinated to the Cu+ ions, including one of the oxygen atoms in each O-H...O hydrogen bond (O...O approximately 2.62 A). Infrared spectra (v(CO) values) of Cu(CO)(CF3CO2) or Cu(CO)(CH3SO3) dissolved in acetonitrile or benzene, with and without added CF3COOH or CH3SO3H, respectively, demonstrate that HA2- anions involving carboxylates or sulfonates are more weakly coordinating than the parent anions RCO2- and RSO3-. Direct current conductivities of THF solutions of Li(CF3CO2) containing varying concentrations of added CF3COOH further demonstrate that Li+ and NEt4+ ion pair much more weakly with H(CF3CO2)2- than with CF3CO2-.     

Synthesis and Structure of Dinuclear Molybdenum Carbonyl Thiolate Compound〔Et_4N〕_2〔Mo_2(CO)_8(SC_6H_4-NH_2-p)_2〕

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｅｘｉｓｔｅｎｃｅａｎｄｓｉｇｎｉｆｉｃａｎｃｅｏｆｔｈｅｍｏｌｙｂｄｅｎｕｍ ｓｕｌｆｕｒｂｏｎｄｉｎｇｉｎｍｏｌｙｂｄｅｎｕｍｅｎｚｙｍｅｓ〔１〕ｈａｖｅｓｔｉｍｕｌａｔｅｄｔｈｅｓｔｕｄｉｅｓｏｎｔｈｅｃｈｅｍｉ...     

A novel organic-inorganic hybrid based on an 8-electron-reduced Keggin polymolybdate capped by tetrahedral, trigonal bipyramidal, and octahedral zinc: synthesis and crystal structure of (CH3NH3)(H2bipy)[Zn4(bipy)3(H2O)2MoV8MoVI4O36)(PO4)].4H2O

Hydrothermal reaction of H(3)PO(3), CH(3)NH(2), zinc(II) acetate, 4,4'-bipyridine (bipy), and (NH(4))(6)Mo(7)O(24).4H(2)O at 180 degrees C led to a novel organic-inorganic layered hybrid, [CH(3)NH(3)][H(2)bipy][Zn(4)(bipy)(3)(H(2)O)(2)Mo(V)(8)Mo(VI)O(36)(PO(4))].4H(2)O (1). Its structure was established by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2(1)/c with cell parameters of a = 17.3032(2), b = 17.8113(3), and c = 23.4597 (4) A, beta = 106.410(1) degrees, V = 6935.6(2) A(3), and Z = 4. The structure of compound 1 features a novel 2D layer built from the 8e-reduced tetracapped Keggin [Zn(4)Mo(12)O(36)(PO(4))](3)(-) anions, which are further interconnected by bridging bipy ligands. The four zinc(II) ions are in tetrahedral, trigonal bipyramidal, and octahedral coordination geometries, respectively.     

[CH3NH3][NH3(CH2)6NH3]H3[P2Mo2W16O62]·H2O的水热合成与表征

首次合成了[CH3NH3][NH3(CH2)6NH3]H3[P2Mo2W16O62]·H2O,通过元素分析、红外光谱和X射线单晶衍射对合成产物进行了表征,并用TGA-DSC研究了化合物的热稳定性.晶体属单斜晶系,P21/m空间群,a=1.2596(3)nm,b=1.8715(4)nm,c=1.9816(4)nm,α=γ=90°,β=90.16(3)°,V=4.671(2)nm3,Z=2,Mr=4358.66,Dc=3.100g·cm-3,μ=19.978mm-1,F(000)=3792,R=0.0835,Rw=0.2026.结果表明,在晶体结构内形成了0.7364nm×0.8354nm的微孔.     

Hydrothermal synthesis and characterization of new pillared layered ethylenediphosphonates of molybdenum(VI), A2[Mo2O5(O3PCH2CH2PO3)] (A = NH4, Tl, Cs, Rb) and K(H3O)[Mo2O5(O3PCH2CH2PO3)

New ethylenediphosphonates of molybdenum, A[Mo2O5(O3PCH2CH2PO3)] (A = NH4 (1), Tl (2), Cs (3), Rb (4)), and K(H3O)[Mo2O5(O3PCH2CH2PO3)] (5), have been synthesized by a hydrothermal method and structurally characterized by X-ray diffraction, spectroscopic, and thermal studies. These compounds consist of pillared anionic layers [Mo2O5(O3PCH2CH2PO3)]2-, with A+, K+, and H3O+ ions in the interlayer region as well as in the cavities within the anionic layers. Single-crystal X-ray structures of compounds 1 and 5 have been determined. They crystallize in the orthorhombic space group Cmca with Z = 8 and have the following unit cell parameters. For 1, a = 25.60(1), b = 10.016(4), and c = 9.635(3) angstroms and for 5, a = 25.63(1), b = 10.007(2), and c = 9.512(1) angstroms.