Normal mode analysis of zinc caprate (Zn)1/2O2C(CH2)8CH3

A normal mode analysis was made for zinc caprate with using the Wilson GF matrix method. Based on the analysis and infrared spectra, structural transition behavior of zinc caprate was discussed.     

The synthesis and crystal structures of two-dimensional coordination polymers of Ph2P(O)-CH2CH2-P(O)Ph2 and Ph2P(O)-C5H3N-P(O)Ph2 with praseodymium

Reactions of Pr(NO3)3 with Ph2P(O)-CH2CH2-P(O)Ph2 and Ph2P(O)-C5H3N-P(O)Ph2 yielded layered network coordination polymers with bidentate ligands spanning the lanthanide atoms in a bridging fashion. The praseodymium cations with "spacer" ligands form two-dimensional building blocks assembling into either square grid or herringbone network.     

Kinetic Monte Carlo model of charge transport in hematite (alpha-Fe(2)O(3))

The mobility of electrons injected into iron oxide minerals via abiotic and biotic electron transfer processes is one of the key factors that control the reductive dissolution of such minerals. Building upon our previous work on the computational modeling of elementary electron transfer reactions in iron oxide minerals using ab initio electronic structure calculations and parametrized molecular dynamics simulations, we have developed and implemented a kinetic Monte Carlo model of charge transport in hematite that integrates previous findings. The model aims to simulate the interplay between electron transfer processes for extended periods of time in lattices of increasing complexity. The electron transfer reactions considered here involve the IIIII valence interchange between nearest-neighbor iron atoms via a small polaron hopping mechanism. The temperature dependence and anisotropic behavior of the electrical conductivity as predicted by our model are in good agreement with experimental data on hematite single crystals. In addition, we characterize the effect of electron polaron concentration and that of a range of defects on the electron mobility. Interaction potentials between electron polarons and fixed defects (iron substitution by divalent, tetravalent, and isovalent ions and iron and oxygen vacancies) are determined from atomistic simulations, based on the same model used to derive the electron transfer parameters, and show little deviation from the Coulombic interaction energy. Integration of the interaction potentials in the kinetic Monte Carlo simulations allows the electron polaron diffusion coefficient and density and residence time around defect sites to be determined as a function of polaron concentration in the presence of repulsive and attractive defects. The decrease in diffusion coefficient with polaron concentration follows a logarithmic function up to the highest concentration considered, i.e., approximately 2% of iron(III) sites, whereas the presence of repulsive defects has a linear effect on the electron polaron diffusion. Attractive defects are found to significantly affect electron polaron diffusion at low polaron to defect ratios due to trapping on nanosecond to microsecond time scales. This work indicates that electrons can diffuse away from the initial site of interfacial electron transfer at a rate that is consistent with measured electrical conductivities, but that the presence of certain kinds of defects will severely limit the mobility of donated electrons.     

C-H activation of ethane by group 4 metal atoms: observation and characterization of the MH-CH2CH3, MH2-(CH2)2, and MH3-CH=CH2 complexes

Group 4 metal atoms excited in the laser ablation process activate ethane to form the C-H insertion product, the metallacyclopropane dihydride, and vinyl metal trihydride complexes as major products. These three new metal hydrides are characterized by their strong M-H stretching absorptions and other weaker modes as predicted by density functional theory vibrational frequency calculations.     

Structural diversity of lithium sulfenamides: 7Li NMR studies in solution and crystal structures of [Li2(eta2-(CH3)3C-NS-C6H4CH(3)-4)2(THF)2] and [Li2(eta1-4-CH3C6H4-NS-C6H4CH(3)-4)2(THF)4

Two lithium sulfenamides were prepared by reaction of (CH(3))(3)C-N(H)-S-C(6)H(4)CH(3)-4 (1) and 4-CH(3)C(6)H(4)-N(H)-S-C(6)H(4)CH(3)-4 (2) with an alkyllithium. The unsolvated sulfenamide Li[(CH(3))(3)C-NS-C(6)H(4)CH(3)-4] (3) was soluble enough for variable-temperature (VT) (7)Li NMR to provide evidence of a dynamic exchange of oligomers in solution. The crystal structures of the solvated sulfenamides of [Li(2)(eta(2)-(CH(3))(3)C-NS-C(6)H(4)CH(3)-4)(2)(THF)(2)] (4) and of [Li(2)(eta(1)-4-CH(3)C(6)H(4)-NS-C(6)H(4)CH(3)-4)(2)(THF)(4)] (6) consisted of dimers in which the anions display different hapticities. The VT (7)Li NMR spectra of 4 suggest that the two different structures exist in equilibrium in toluene-THF mixtures. These compounds are easily oxidized to the neutral thioaminyl radicals as identified by EPR spectroscopy.     

Blue-luminescent/electroluminescent Zn(II) compounds of 7-azaindole and N-(2-pyridyl)-7-azaindole: Zn(7-azaindole)2(CH3COO)2, Zn(NPA)(CH3COO)2, and Zn(NPA)((S)-(+)-CH3CH2CH(CH3)COO)2 (NPA = N-(2-pyridyl)-7-azaindole)

A new 7-azaindole zinc(II) compound, Zn(7-azaindole)2(CH3COO)2 (1), a new ligand N-(2-pyridyl)-7-azaindole (NPA), and two NPA zinc(II) complexes, Zn(NPA)(CH3COO)2 (2) and Zn(NPA)((S)-(+)-CH3CH2CH(CH3)COO)2 (3), have been synthesized and structurally characterized. Compound 1 has a tetrahedral geometry, whereas compounds 2 and 3 have irregular six-coordinate geometry. The NPA ligand in compounds 2 and 3 functions as a bidentate chelate to the zinc center. Compound 1 has a blue luminescence in the solution and the solid state. Compounds 2 and 3 emit a blue color in the solid state. In solution, compounds 2 and 3 are fluxional, as established by 1H NMR experiments. Compound 1 is thermally stable, whereas compounds 2 and 3 undergo decomposition when heated in the solid state. A blue electroluminescent device using compound 1 as the emitting layer has been fabricated. Crystal data: NPA, monoclinic, P2(1)/c, a = 13.993(5) A, b = 8.456(3) A, c = 16.886(5) A, beta = 104.666(12) degrees, V = 1932.9(11) A3; 1, triclinic, P1, a = 9.5114(18) A, b = 10.460(7) A, c = 11.002(3) A, alpha = 117.18(3) degrees, beta = 103.287(18) degrees, gamma = 90.94(2) degrees, V = 938.3(7) A3; 2, monoclinic, C2/c, a = 13.234(6) A, b = 9.373(3) A, c = 13.956(7) A, beta = 113.24(3) degrees, V = 1590.7(12) A3; 3, monoclinic, P2(1), a = 11.047(7) A, b = 15.343(9) A, c = 13.785(8) A, beta = 100.123(9) degrees, V = 2300(2) A3.     

Vibrational coupling in oxo-centred trinuclear clusters: oxygen-16/18 isotopic substitution studies of [Fe3III(O)(O2CC(CH3)3)6(py)3][FeCl4] and [Fe2(III)FeII(O)(O2CC(CH3)3)6(py)3

IR spectra are reported for the compounds [Fe3O(O2CC(CH3)3)6(py)3][FeCl4] and [Fe3O(O2CC(CH3)3)6(py)3]. Using isotopic substitution at the central oxygen atom, the assignments of the in-plane and out-of-plane vibrations of this atom are confirmed, and coupling is demonstrated between the in-plane modes v(as)(Fe3O) and carboxylate deformation modes rho(r)(C-CO2).     

Hydrothermal single-crystal growth in the systems Ag/Hg/X/O (X = VV, AsV): crystal structures of (Ag3Hg)VO4, (Ag2Hg2)3(VO4)4, and (Ag2Hg2)2(HgO2)(AsO4)2 with the unusual tetrahedral cluster cations (Ag3Hg)3+ and (Ag2Hg2)4+ and crystal structure of AgHgVO4

Single crystals of (Ag3Hg)VO4 (I), (Ag2Hg2)3(VO4)4 (II), AgHgVO4 (III), and (Ag2Hg2)2(HgO2)(AsO4)2 (IV) were grown under hydrothermal conditions (250 degrees C, 5 d) from starting mixtures of elementary mercury, silver nitrate, ammonium vanadate, and disodium hydrogenarsenate, respectively. All crystal structures were determined from X-ray diffraction data, and their chemical compositions were confirmed by electron microprobe analysis. I crystallizes in the tillmannsite structure, whereas II-IV adopt new structure types: (I) I4, Z = 2, a = 7.7095(2) A, c = 4.6714(2) A, 730 structure factors, 24 parameters, R[F2 > 2sigma(F2)] = 0.0365; (II) I42d, Z = 4, a = 12.6295(13) A, c = 12.566(3) A, 1524 structure factors, 55 parameters, R[F2 > 2sigma(F2)] = 0.0508; (III) C2, Z = 4, a = 9.9407(18) A, b = 5.5730(8) A, c = 7.1210(19) A, beta = 94.561(10) degrees , 1129 structure factors, 48 parameters, R[F2 > 2sigma(F2)] = 0.0358; (IV) P31c, Z = 2, a = 6.0261(9) A, c = 21.577(4) A, 1362 structure factors, 52 parameters, R[F2 > 2sigma(F2)] = 0.0477. The most striking structural features of I, II, and IV are the formation of tetrahedral cluster cations (Ag3Hg)3+ and (Ag2Hg2)4+, respectively, built of statistically distributed Ag and Hg atoms with a metal-metal distance of about 2.72 A. The electronic structure of these clusters can formally be considered as two-electron-four-center bonding. The crystal structure of III differs from the protrusive structure types insofar as silver and mercury are located on distinct crystallographic sites without a notable metal-metal interaction >3.55 A. All crystal structures are completed by tetrahedral oxo anions XO4(3-) (X = VV, AsV) and for IV additionally by a mercurate group, HgO2(2-).     

New insights into the thermal stability of Mn12 clusters: the case of complex [Mn12O12(O2CC[triple bond]-CH)16(H2O)4] x 3H2O and its thermolysis derived [Mn3(O2CC[triple bond]CH)6(H2O)4] x 2H2O complex

Two novel Mn12 derivatives [Mn12O12(O2CC[triple bond]CH)16(H2O)4] x 3H2O (1) and [Mn12(O2CC[triple bond]CC6H5)16(H2O)4] x 3H2O (2) have been prepared and characterized. Magnetic measurements confirm that both function as single-molecule magnets (SMM), showing frequency-dependent out-of-phase AC susceptibility signals and magnetization hysteresis curves. Thermal stability studies of both complexes were first conducted in the solid state. While complex 1 undergoes a sudden exothermal decomposition at T(onset) = 118 degrees C, complex 2 exhibits a higher stability. Thermolysis reaction of 1 was hence assessed in solution to yield dark red crystals of a two-dimensional Mn(II)-based co-ordination polymer [Mn3(O2CC[triple bond]CH)6(H2O)4] x 2H2O (3), which corresponds to an extended sheet-like structure that crystallizes in the monoclinic space group P2(1)/n; a = 9.2800(2) angstroms, b = 9.4132(2) angstroms, c = 14.9675(3) angstroms, beta = 99.630(1) degrees, and Z = 2. Finally, the magnetic properties of complex 3 have been studied on an oriented single crystal over two different orientations of the reciprocal vector versus the external field.     

含硫、氮Schiff碱配合物—二水二分之一二甲基亚砜醋酸四邻香草醛缩胺基硫脲合镉（Ⅱ）的合成及晶体结构

Ｘ射线单晶衍射结果表明，三核镉配合物Ｃｄ３［ＣＨ３Ｏ（Ｏ）Ｃ６Ｈ３ＣＨ＝ＮＮＨＣ（Ｓ）ＮＨ２］４·［ＣＨ３ＣＯＯ］２·１／２［ＣＨ３Ｓ（Ｏ）ＣＨ３］·２Ｈ２Ｏ为单斜晶系，空间群为Ｃ２／ｃ，ａ＝３．４２１４（４），ｂ＝１．１５８１（２），ｃ＝１．７９３２（５）ｎｍ，β＝１１９．７６（１）°，Ｖ＝６．１６８ｎｍ３，Ｍｒ＝１４２７．４３，Ｚ＝４，Ｄｃ＝１．５４ｇ／ｃｍ３，μ＝１２．４８ｃｍ（－１），Ｆ（０００）＝２８６０，最后偏离因子Ｒ＝０．０６６．     

Fast tunneling Jahn–Teller isomer of the [Mn12O12(O2CC6H4-2-CH3)16(H2O)4] · S single-molecule magnet

The single-crystal X-ray structure of the single-molecule magnet [Mn₁₂O₁₂(O₂CC₆H₄-2-CH₃)₁₆(H₂O)₄] · CH₂Cl₂ · 2H₂O (complex 1) is reported. Complex 1 is a new example of a “Jahn–Teller isomer”, since it has two Mn(III) ions with abnormally oriented Jahn–Teller elongation axes. Complex 1 has a lower activation energy (U_eff = 29 K) for magnetization reversal relative to other reported [Mn₁₂O₁₂] type molecules (e.g., U_eff = 70 K for Mn₁₂Ac). Single-crystal low temperature magnetization measurements are reported that confirm that complex 1 is a single-molecule magnet. High-field electron paramagnetic resonance measurements were performed on a single crystal to give the spin Hamiltonian parameters.     

Improved kinetics of LiNi(1/3)Mn(1/3)Co(1/3)O2 cathode material through reduced graphene oxide networks

An electronically conducting 3D network of reduced graphene oxide (RGO) was introduced into LiNi(1/3)Mn(1/3)Co(1/3)O(2) (LNMC) cathode material in a special nano/micro hierarchical structure. The rate test and cycling measurement showed that the hierarchical networks remarkably improve the high rate performance of LNMC electrode for lithium-ion batteries. The effect of RGO conducting networks on kinetic property was investigated by electrochemical impedance spectroscopy (EIS) and potentiostatic intermittent titration (PITT). The EIS results reveal that the RGO network greatly decreases the resistance of lithium batteries, especially the charge transfer resistance which can be attributed to the significantly improved conducting networks. The enhancement of apparent diffusion coefficient by the RGO conducting networks is shown by PITT. The power performance was found to be limited by the electrical conduction in the two-phase region, which can be greatly facilitated by the hierarchical RGO network together with carbon black. The as-obtained LNMC/RGO cathode exhibits an outstanding electrochemical property supporting the design idea of electronically conducting 3D networks for the high-energy and high-power lithium-ion batteries.     

Two new hybrid organic/inorganic copper(II)-oxovanadate(V) diphosphonates: [Cu2(phen)2(O3PCH2PO3)(V2O5)(H2O)] x H2O and [Cu2(phen)2(O3P(CH2)3PO3)(V2O5)] x C3H8. Synthesis, structure, and magnetic properties

Two new hybrid organic/inorganic copper oxovanadium diphosphonates [Cu2(phen)2(O3PCH2PO3)(V2O5)(H2O)] x H2O (1) and [(Cu2(phen)2(O3P(CH2)3PO3)(V2O5)] x C3H8 (2) have been obtained by hydrothermal synthesis. The compounds are monoclinic, and they crystallize in the space group P2(1)/n with cell parameters of a = 11.788(2) A, b = 17.887(3) A, c = 14.158(2) A, and beta = 93.99(0) degrees and in the space group C2/c with cell parameters of a = 11.025(1) A, b = 18.664(2) A, c = 15.054(2) A, and beta = 90.06(0) degrees, respectively. Both compounds present two-dimensional frameworks built up from infinite chains of corner-sharing vanadium tetrahedra and diphosphonate groups connected by copper tetramers for (1) and copper dimers for (2). The remarkable feature of (2) is the encapsulation of propane molecules, stabilized by strong hydrogen bonding between the layers. The magnetic properties of the compounds have been investigated showing antiferromagnetic coupling with Tmax = 64 K for (1) and Curie-like paramagnetic behavior for (2).     

Synthesis, crystal structure and optical properties of [Ag(UO2)3(OAc)9][Zn(H2O)4(CH3CH2OH)2]: a novel compound containing closed-shell 3d10, 4d10 and 5d10 metal ions

[Ag(UO(2))(3) (OAc)(9)][Zn(H(2)O)(4)(CH(3)CH(2)OH)(2)] (, OAc = CH(3)COO(-)) crystallized from an ethanol solution and its structure was determined by IR spectroscopy, elemental analysis, (1)H NMR, (13)C NMR and X-ray crystallography; it is composed of [Zn(H(2)O)(4)(CH(3)CH(2)OH)(2)](2+) cations and [Ag(UO(2))(3)(OAc)(9)](2-) anions in which triuranyl [(UO(2))(OAc)(3)](3) clusters are linked by the Ag ion.     

The ball-shaped heteropolytungstates [[Sn(CH3)2(H2O)]24[Sn(CH3)2]12(A-XW9O34)12]36- (X=P, As): stability, redox and electrocatalytic properties in aqueous media

The electrochemical behavior of the ball-shaped heteropolytungstates [[Sn(CH(3))(2)(H(2)O)](24)[Sn(CH(3))(2)](12)(A-XW(9)O(34))(12)](36-) (X=P, 1; As, 2) was examined in aqueous electrolytes by redissolution of their respective mixed cesium-sodium salts Cs(14)Na(22)[[Sn(CH(3))(2)(H(2)O)](24)[Sn(CH(3))(2)](12) (A-PW(9)O(34))(12)]149 H(2)O (Cs(14)-1) and Cs(14)Na(22)[[Sn(CH(3))(2)(H(2)O)](24)[Sn(CH(3))(2)](12)(A-AsW(9)O(34))(12)]149 H(2)O (Cs(14)-2). In the studied media, Cs(14)-2 is readily soluble in contrast to the significantly less soluble Cs(14)-1. The solubility of Cs(14)-1 is increased by the presence of Li(+) ions in solution. Gel filtration studies with 1 and 2 rule out a decay of the dodecameric spherical assemblies to Keggin-based monomers on the timescale of the experiment. By UV/Vis spectroscopy and cyclic voltammetry, 2 was found to be significantly less stable than 1 and both polyanions also show rather different decomposition pathways. Polyanion 1 collapses first into Keggin-type monomers which might contain the trilacunary [A-alpha-PW(9)O(34)](9-). The final monomeric species obtained from 1 appears to be very similar to [PW(11)O(39)](7-), which is the final transformation product of [A-alpha-PW(9)O(34)](9-) in the same media. In contrast, 2 does not seem to follow an analogous transformation pathway as that of the trilacunary [A-alpha-AsW(9)O(34)](9-). Importantly, stabilization of 1 is observed in chloride media. The fairly long-term stability of 1 in 1 M LiCl, pH 3, has allowed for its electrochemical study to be carried out. The solid-state cyclic voltammogram of 1 entrapped in a carbon paste electrode shows the same characteristics as 1 dissolved in chloride solutions, thus supporting the conclusion that the polyanion is stable in these environments. Controlled potential coulometry on 1 indicates that the number of electrons consumed in the first wave is larger than twenty. To our knowledge, 1 constitutes the first example of a molecule that can take up such a large number of electrons resulting in a chemically reversible W-wave. These properties show promise for future fundamental and applied studies. Polyanion 1 is also efficient in the electrocatalytic reduction of NO(x), including nitrate. Finally, a remarkable interaction was found between 1 and NO, a highly promising feature for biomimetic applications.