Concerted halogen and hydrogen bonding in [RuI2(H2dcbpy)(CO)2]···I2···(CH3OH)···I2···[RuI2(H2dcbpy)(CO)2

A new type of concerted halogen bond-hydrogen bond interaction was found in the solid state structure of [RuI(2)(H(2)dcbpy)(CO)(2)]···I(2)···(MeOH)···I(2)···[RuI(2)(H(2)dcbpy)(CO)(2)]. The iodine atoms of the two I(2) molecules interact simultaneously with each other and with the OH group of methanol of crystallization. The interaction was characterized by single crystal X-ray measurements and by computational charge density analysis based on DFT calculations.     

Infrared spectroscopy and modeling of co-crystalline CO2·C2H2 aerosol particles. I. The formation and decomposition of co-crystalline CO2·C2H2 aerosol particles

Aerosol particles composed of co-crystalline CO(2)·C(2)H(2) were generated in a bath gas cooling cell at cryogenic temperatures and investigated with infrared spectroscopy between 600 and 4000 cm(-1). Similar to results obtained for thin films of the co-crystal [T. E. Gough and T. E. Rowat, J. Chem. Phys. 109, 6809 (1998)], this phase was found to be metastable and decomposed into pure CO(2) and pure C(2)H(2). These decomposed aerosols were characterized through (i) a comparison to experimentally prepared aerosols of mixed CO(2) and C(2)H(2) of known architectures and (ii) the modeling of infrared spectra. A likely architecture after decomposition are C(2)H(2)-CO(2) core-shell particles with a disk-like shape. The co-crystalline CO(2)·C(2)H(2) aerosols prior to decomposition are modeled and analyzed in detail in the subsequent paper (Part II).     

Photoelectron spectroscopy of (CO2)n(H2O) m − clusters

Photoelectron spectra of (CO₂)_nH₂O^? (2≤n≤8) and (CO₂)_n(H₂O) ₂ ^? (1≤n≤2) were measured at the photon energy of 3.49 eV. The spectra show unresolved broad features, which are approximated by Gaussians. The vertical detachment energies (VDEs) were determined as a function of the cluster size. For (CO₂)_nH₂O^?, the VDE-n plots exhibit a sharp discontinuity between n=3 and 4; the VDE value is ≈3.5 eV at n=3, while it drops down abruptly to 2.59 eV at n=4. This discontinuity in VDE is ascribed to "core switching" at n=4; a C₂O ₄ ^? dimer anion forms the core of (CO₂)_nH₂O^? for n≤3, while a monomer CO ₂ ^? is the core for n≥4. The (CO₂)₂(H₂O) ₂ ^? ion has a VDE of 2.33 eV, indicating the presence of a CO ₂ ^? monomer core in the binary clusters containing two H₂O molecules.     

Reactions of the Cluster Anion [HRu3(CO)11)]− with Dicyclohexylphosphine: Synthesis and Molecular Structure of H2Ru3(CO)8(PCy2)2 and H2Ru3(CO)6(PCy2)2(HPCy2)2

The cluster anion [HRu₃(CO)₁₁]^- (1) reacts with dicyclohexylphosphine in THF solution to give the anionic derivative [HRu₃(CO)₈(PCy₂)₂]^- (2), protonation of which yields the neutral cluster H₂Ru₃(CO)₈(PCy₂)₂ (3) and, in the presence of excess phosphine, HRu₃(CO)₇(PCy₂)₃ (4). In protic methanol as reaction medium, the reaction of 1 with HPCy₂ gives directly the neutral complex H₂Ru₃(CO)₆(PCy₂)₂(HPCy₂)₂ (5), together with 4. The single-crystal structure X-ray analysis of 3 shows a closed triangular Ru₃ framework. The electron count is in accordance with the EAN rule, but the structure analysis of 5 reveals an open, almost linear Ru₃ skeleton, which is electron-deficient with respect to the EAN rule.     

Syntheses and structures of p-HOOCC6F4COOH · H2O (H2L · H2O) and luminescent coordination polymers [Tb2(H2O)4(L)3 · 2H2O] n and Tb2(Phen)2(L)3 · 2H2O

Compounds p-HOOCC₆F₄COOH · H₂O (H₂L · H₂O), [Tb₂(H₂O)₄(L)₃ · 2H₂O] _n (I), and Tb₂(Phen)₂(L)₃ · 2H₂O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H₂L · H₂O is built of centrosymmetric molecules H₂L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb₂(H₂O)₄(L)₃] _n and molecules of water of crystallization. The ligands are the L^2? anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO₉ is a distorted three-capped trigonal prism. Acid H₂L manifests photoluminescence in the UV region (??_max = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb³⁺ ions, and the band with ??_max = 545 nm (transition ⁵ D ₄?? ⁷ F ₅) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I.     

Structure of the complex [trans-SnF4(H2O)2· (18-crown-6)· 2H2O]

The molecular and crystal structure of the title complex (I) obtained by addition of tin fluoride in a hydrofluoric acid solution to 18-crown-6 in methanol was investigated by X-ray structure analysis. The crystals are monoclinic, space group P2₁/n, a = 13.497(3), b = 7.806(2), c = 9.892(2) Å, β = 95.57(3)°, Z = 2 for C₁₂H₃₂F₄O₁₀Sn. In the polymer chain, the crown ether molecules alternate with the inorganic complexes [trans-SnF₄(H₂O)₂] and are linked to them by O-H...O type hydrogen bonds involving the intermediate water molecules. The weak C-H...F interactions bind the chains into the layers which are parallel to the xz plane.     

Thermal decomposition of Ln(C2H5CO2)3·H2O (Ln?=?Ho, Er, Tm and Yb)

The thermal decomposition of Ho(III), Er(III), Tm(III) and Yb(III) propionate monohydrates in argon was studied by means of thermogravimetry (TG), differential thermal analysis (DTA), IR-spectroscopy and X-ray diffraction (XRD). Dehydration takes place around 90?°C. It is followed by the decomposition of the anhydrous propionates to Ln₂O₂CO₃ (Ln?=?Ho, Er, Tm or Yb) with the evolution of CO₂ and 3-pentanone (C₂H₅COC₂H₅) between 300 and 400?°C. The further decomposition of Ln₂O₂CO₃ to the respective sesquioxides Ln₂O₃ is characterized by an intermediate plateau extending from approximately 500?C700?°C in the TG traces. This stage corresponds to an overall composition of Ln₂O_2.5(CO₃)_0.5 but is more probably a mixture of Ln₂O₂CO₃ and Ln₂O₃. The stability of this intermediate state decreases for the lighter rare-earth (RE) compounds studied. Full conversion to Ln₂O₃ is achieved at about 1,100?°C. The overall thermal decomposition behaviour of the title compounds is similar to that previously reported for Lu(C₂H₅CO₂)₃·H₂O.     

Comprehensive thermochemistry of W-H bonding in the metal hydrides CpW(CO)2(IMes)H, [CpW(CO)2(IMes)H](•+), and [CpW(CO)2(IMes)(H)2]+. Influence of an N-heterocyclic carbene ligand on metal hydride bond energies

The free energies interconnecting nine tungsten complexes have been determined from chemical equilibria and electrochemical data in MeCN solution (T = 22 °C). Homolytic W-H bond dissociation free energies are 59.3(3) kcal mol(-1) for CpW(CO)(2)(IMes)H and 59(1) kcal mol(-1) for the dihydride [CpW(CO)(2)(IMes)(H)(2)](+) (where IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene), indicating that the bonds are the same within experimental uncertainty for the neutral hydride and the cationic dihydride. For the radical cation, [CpW(CO)(2)(IMes)H](?+), W-H bond homolysis to generate the 16-electron cation [CpW(CO)(2)(IMes)](+) is followed by MeCN uptake, with free energies for these steps being 51(1) and -16.9(5) kcal mol(-1), respectively. Based on these two steps, the free energy change for the net conversion of [CpW(CO)(2)(IMes)H](?+) to [CpW(CO)(2)(IMes)(MeCN)](+) in MeCN is 34(1) kcal mol(-1), indicating a much lower bond strength for the 17-electron radical cation of the metal hydride compared to the 18-electron hydride or dihydride. The pK(a) of CpW(CO)(2)(IMes)H in MeCN was determined to be 31.9(1), significantly higher than the 26.6 reported for the related phosphine complex, CpW(CO)(2)(PMe(3))H. This difference is attributed to the electron donor strength of IMes greatly exceeding that of PMe(3). The pK(a) values for [CpW(CO)(2)(IMes)H](?+) and [CpW(CO)(2)(IMes)(H)(2)](+) were determined to be 6.3(5) and 6.3(8), much closer to the pK(a) values reported for the PMe(3) analogues. The free energy of hydride abstraction from CpW(CO)(2)(IMes)H is 74(1) kcal mol(-1), and the resultant [CpW(CO)(2)(IMes)](+) cation is significantly stabilized by binding MeCN to form [CpW(CO)(2)(IMes)(MeCN)](+), giving an effective hydride donor ability of 57(1) kcal mol(-1) in MeCN. Electrochemical oxidation of [CpW(CO)(2)(IMes)](-) is fully reversible at all observed scan rates in cyclic voltammetry experiments (E° = -1.65 V vs Cp(2)Fe(+/0) in MeCN), whereas CpW(CO)(2)(IMes)H is reversibly oxidized (E° = -0.13(3) V) only at high scan rates (800 V s(-1)). For [CpW(CO)(2)(IMes)(MeCN)](+), high-pressure NMR experiments provide an estimate of ΔG° = 10.3(4) kcal mol(-1) for the displacement of MeCN by H(2) to give [CpW(CO)(2)(IMes)(H)(2)](+).     

ZnSO4·CO(NH2)2·2H2O和MgCl2·NH4Cl·6H2O的热分解动力学研究

采用TG-DSC研究了ZnSO4·CO(NH2)2·2H2O和MgCl2·NH4Cl·6H2O的热分解反应,并对其中的脱水过程及部分分解过程进行了动力学计算,由Fridman、Ozawa-Flynn-Wall、ASTME698三种方法得出峰温时的活化能值与指前因子值,通过优化选择出了热分解过程最佳机理函数.     

The reactions of AgI electrophile with [Fe2(η-C5H5)2(CO)2(L){CN(Me)H}]+ and [Fe2(η-C5H5)2(CO)2{CN(Me)H}2]2+ salts (L = CO or CNMe)

The protonated species [Fe₂(η-C₅H₅)₂(CO)₂(η-CO){μ-CN(Me)H}]X, [Fe₂(η-C₅H₅)₂(CO)(CNMe)(μ-CO){μ-CN(Me)H}][X], and [Fe₂(η-C₅H₅)₂(CO)₂{η-CN(Me)H}₂][X]₂ react with one equivalent of AgY. The Ag⁺ and one H⁺ act together as a two-electron oxidant. Silver metal is precipitated quantitatively and the substrates cleaved to give mono-nuclear products of the type (a) [Fe(η-C₅H₅)(CO)(L)X] and [Fe(η-C₅H₅(CO)(L)Y] or (b) Fe(η-C₅H₅(CO)(L)(CNMe)][X] (L = CO, CNMe). If X⁻ and Y⁻ are both coordinating anions such as NO₃⁻, I⁻, or Br⁻ or the solvent is MeCN products of type (a) are usually obtained with X = Y = MeCN⁺ if acetonitrile is used as the solvent. However, if either X⁻ or Y⁻ is a non-coordinating anion such as BF₄⁻ or PF₆⁻ and methanol is the solvent, the products are usually those of type (b). When X⁻ = [p-MeC₆H₄SO₃]⁻, both types of products are obtained in significant amounts. If two equivalents of Ph₃P are added to the methanol solution of [Fe₂(η-C₅H₅)₂(CO)₂{-CN(Me)H}₂[BF₆]₂, no reaction takes place until the third equivalent of AgNO₃ has been added. The products have been isolated and characterized by analysis and infrared spectroscopy. The previously unreported [Fe₂(η-C₅H₅)₂(CO)(CNMe)(η-CO){η-CN(Me)H}] X salts are described for X⁻ = BF₄⁻, PF₆⁻, Br⁻ · 2H₂O, I⁻ · H₂O, NO₃⁻ · 0.5H₂O, and p-MeC₆H⁴SO₃⁻.     

Luminescent copper(I) halide adducts of [Au(im(CH2py)2)2]PF6 exhibiting short Au(I)···Cu(I) separations and unusual semibridging NHC ligands

The picolyl-substituted NHC complex [Au(im(CH(2)py)(2))(2)]PF(6) (1) reacts with two equivalents of copper(I) halides, affording compounds [Au(im(CH(2)py)(2))(2)(CuX)(2)]PF(6) (X = Cl, 2; Br, 3; I, 4). Each complex contains a nearly linearly coordinated [Au(NHC)(2)](+) center where the two picolyl groups on each im(CH(2)py)(2) ligand chelate a single copper atom. The Cu(I) center resides in a distorted tetrahedral environment and is coordinated to two pyridyl groups, a halide ion, and a gold metalloligand. The Au(I)-Cu(I) separations measure 2.7030(5), 2.6688(9), and 2.6786(10) ? for 2-4, respectively. Additionally, each Cu(I) center is further coordinated by a semibridging NHC ligand with short Cu-C separations of ~2.3 ?. In solution, these complexes dissociate the Cu(I) ion. In the solid state, 2-4 are photoluminescent with respective emission maxima of 512, 502, and 507 nm. The reaction of [Au(im(CH(2)py)(2))(2)]PF(6) with four equivalents of CuBr afforded the coordination polymer {[AuCu(2)Br(2)(im(CH(2)py)(2))(2)]Br·3CH(3)CN}(n) (5). This polymeric complex contains [Au(NHC)(2)](+) units interconnected by Cu(2)Br(2) dimers. In 5, the Au-Cu separations are long at 4.23 and 4.79 ?, while the Cu-Cu distance is considerably shorter at 2.9248(14) ?. In the solid state, 5 is photoluminescent with a broad band appearing at 533 nm.     

A diruthenium soft ferromagnet showing T(c) = 3.0 K: Mn4(H2O)16H[Ru2(CO3)4]2[Ru2(CO3)4(H2O)2]·11H2O

A three-dimensional CO(3)(2-)-bridged Mn(II)-Ru(2)(II,III) complex, Mn(4)(H(2)O)(16)H[Ru(2)(CO(3))(4)](2)[Ru(2)(CO(3))(4)(H(2)O)(2)]·11H(2)O (1), was synthesized by self-assembling Ru(2)(CO(3))(4)(3-) paddle-wheel precursors and Mn(2+) cations. It contains an unprecedented layer [Ru(2)(CO(3))(4)](n)(3n-) with (4,4) network. The ferromagnetic coupling between spin centers results in ordering below 3.0 K.     

Synthesis,Crystal Structure and Spectral Properties of [Ce(NO3)5(H2O)2]·2(Hphen)·(H2O)

A novel complex [Ce(NO3)5(H2O)2]·2(Hphen)·(H2O) (phen =1,10-phenanthroline) with formula C24H24CeN9O18 and Mr = 866.64 has been synthesized and structurally characterized by X-ray diffraction. It crystallizes in triclinic, space group Pī with a = 7.5534(2), b = 8.083(2), c = 25.8377(6) A, α = 86.847(1), β = 89.937(1), γ = 86.981(1)o, V = 1572.94(6) A3, Dc = 1.830 g/cm3, F(000) = 866, β = 1.545 cm-1 and Z = 2. The final refinement gave R = 0.0486 and wR = 0.1278 for 4852 observed reflections with I > 2σ(I). It consists of discrete [Ce(NO3)5(H2O)2]2- anion, two Hphen+ cations and a lattice water molecule. In the compound, all of the five nitrates are bidentate, and the coordination of Ce(III) is 12. The photo-luminescence of this compound was also investigated.     

Synthesis, crystal structure and electrochemical properties of [Co(phen)3] · (H3btec) · (H2btec)0.5 · DMF · 6H2O

A new complex [Co(phen)₃] · (H₃btec) · (H₂btec)_0.5 · DMF · 6H₂O (1) (H₄btec = 1,2,4,5-Benzenetetracarboxylic acid, phen = 1,10-phenanthroline, DMF = dimethylformamide) was synthesized by the reaction of pyromellitic dianhydride, phen · H₂O and CoSO₄ · 7H₂O. Complex 1 crystallizes in the triclinic system, space group P-1 with a = 11.8123(14) ?, b = 13.0356(16) ?, c = 17.575(2) ?, ?? = 91.461(2)°, ?? = 101.347(2)°, ?? = 99.830(2)°, FW = 1159.94, Z = 2, V = 2609.5(5) ?³. X-ray crystal structural determination indicates that the Co(II) ion is octahedral coordinated by six nitrogen atoms of three phenanthroline ligands. The [Co(phen)₃]²⁺ cation engages its phen ligands in ??-?? interactions with H₂btec anion. Extensive hydrogen bonding interactions occur between water molecules, DMF, H₃btec and H₂btec anions. The highly-crystalline compounds 1, which are insoluble in water as well as common organic solvents, have been characterized in the solid-state by elemental analysis, thermogravimetric analysis and IR spectra. Moreover, the study of the electrochemistry of complex 1 was carried out by using cyclic voltammetry. It revealed that the Co(II) complex exhibits a quasi-reversible one-electron redox process.     

Structure of (C3H5NH3)2H2P2O7·H2O

The bis(cyclopropylammonium)dihydrogenodiphosphate monohydrate is a new diphosphate associated with the organic molecule C₃H₅NH₂. We report the chemical preparation and the crystal structure of this organic cation diphosphate. (C₃H₅NH₃)₂H₂P₂O₇.H₂O is orthorhombic (S.G. : P2₁2₁2₁), with Z = 4 and the following unit-cell parameters : a = 4.828(1) Å, b = 11.011(1) Å, c = 25.645(2) Å. The P₂O₇ groups and H₂O water molecules form a succession of bidimensional layers perpendicular to the c axis. The organic cations ensure the three-dimensional cohesion by NH-O hydrogen bonds.     

Thermal decomposition of RE(C2H5CO2)3·H2O (RE = Dy,Tb, Gd,Eu and Sm)

The thermal decomposition of Dy(III), Tb(III), Gd(III), Eu(III), and Sm(III) propionate monohydrates was studied in argon by means of simultaneous differential thermal analysis and thermogravimetry, infrared-spectroscopy, X-ray diffraction, and optical microscopy. After dehydration, which takes place below 120 °C, all salts decompose into dioxycarbonates with simultaneous release of CO₂ and C₂H₅COC₂H₅ (3-pentanone) between 250 and 460 °C. However, whereas the anhydrous Dy-, Tb-, and Gd-propionates appear to transform into RE₂O₂CO₃ (rare earth [RE] = Dy, Tb, Gd) in a single step, an intermediate stage involving a RE₂O(C₂H₅CO₂)₄ composition was evidenced in the case of the Eu- and Sm-propionates. For all compounds, further decomposition of RE₂O₂CO₃ into the corresponding sesquioxides (RE₂O₃) is accompanied by the release of CO₂. The thermal decomposition of Dy- and Tb-propionates occurs entirely in the solid state. In contrast the dehydrated Gd-, Eu-, and Sm-propionates melt at increasingly higher temperatures. Evidence for recrystallization was found in conjunction with the onset of decomposition of these three propionates.     

Crystal structure of Na2[(UO2)2(SeO4)3(H2O)2] · 6.5H2O

The compound Na₂[(UO₂)₂(SeO₄)₃(H₂O)₂] · 6.5H₂O (I) is studied using X-ray diffraction. The compound crystallizes in the monoclinic crystal system with the unit cell parameters a = 19.7366(8) Å, b = 10.8206(4) Å, c = 21.3577(8) Å, β = 103.4311(1)°, Z = 4, and the space group P2₁/c, R ₁ = 0.0379. Compound I is found to be a representative of the crystal-chemical group A₂T ₂ ³ B²M ₂ ¹ (A = UO ₂ ²⁺ ) of uranyl complexes and contains the cage group [(UO₂)₂(SeO₄)₃(H₂O)₂]^2?.     

Insertion reactions of t-Bu(η5-C5H5)Fe(CO)2

The complex t-Bu(η⁵-C₅H₅)FE(CO)₂ has been treated with triphenylphosphine in refluxing THF to produce t-BuCO(η⁵-C₅H₅)Fe(CO)(PPh₃). The large steric bulk of the t-butyl group suggests that this reaction should be faster than the reaction involving the methyl group, and a kinetic investigation illustrates this to be the case. The same steric bulk predicts that the reaction with SO₂ should be slow, and indeed we have been unable to effect the related SO₂ insertion reaction. Attempts to prepare the corresponding t-Bu(η⁵-C₅H₅)W(CO)₃ led to formation of the related isobutyl complex.     

The solid-state isomerization of cis- and trans-(η5-C5H4Me)Mo(CO)2(P(OiPr)3)I

The cis- and trans-(η⁵-C₅H₄Me)Mo(CO)₂(P(OⁱPr)₃)I complexes undergo a bi-directional thermal ligand isomerization reaction to yield an equilibrium mixture of isomers (30/70 cis/trans ratio, 90 °C, < 80 min) in the solid state. The activation energy barrier for the cis-trans isomerization reaction (80–100 °C) was found to be 68 ± 10 kJ mol^–1. In benzene (reflux, 2 h) this isomer ratio was found to be 70:30 cis/trans. DSC and powder XRD studies have revealed reactions that occur in the solid state entailing decomposition and isomerization. DSC experiments did not reveal the presence of the cis–trans isomerization reaction.