Reactions of SiH2(X̄1A1) with H2, CH4, C2H4, SiH4 and Si2H6 at 298 K

Reaction rate constants of SiH₂(X̄¹A₁) have been directly measured for the first time using the laser photolysis—laser-induced fluorescence method. The preparation of SiH₂ radical in the laser photolysis (193 nm) of phenylsilane and the concentration of the radical is demonstrated by a dye laser at 580.1 nm (X̄¹A₁-Ā¹B₁). The reaction rate constants of SiH₂(X̄¹A₁) with H₂, CH₄, C₂H₄, SiH₄ and Si₂H₆, are 0.001, 0.01, 0.97, 1.1 and 5.7×10⁻¹⁰ cm³ molecule⁻¹ s⁻¹, respectively. For SiH₂(Ā¹B₁(0.2,0)), the collision-free lifetime is 0.6 μs and the quenching rate constant for He is 3.8×10⁻¹⁰ cm³ molecule⁻¹ s⁻¹.     

1,2-C4H6→2-C4H6异构化反应机理的理论研究

采用自洽场分子轨道UHF/6-31G**从头算法,研究了1,2-C4H6→2-C4H6异构化反应机理,优化了基态势能面上反应物、过渡态、中间体和产物的几何构型,并对各驻点能量进行了零点能校准.结果表明该反应经历一个1-甲基环丙烯生成产物比经两步氢迁移反应历程更易发生.     

Hydrothermal Synthesis and Crystal Structure of a New Phosphonate： {[Cu（1,10-phen）]2-（H2O3PCH2C6H4C6H4CH2PO3H）2-（HO3PCH2C6H4C6H4CH2PO3H） }n

1 INTRODUCTION Metal organophosphonates have attracted considerable attention for over three decades due to their potential or practical applications, include- ing ion exchanges[1, 2], molecular sensors[3] and optics[4, 5]. Recently, a number of porous m…     

1,2—C4H6→2—C4H6异构化反应机理的理论研究

采用自洽场分子轨道ＵＨＦ／６－３１Ｇ＊＊从头算法，研究了１，２－Ｃ４Ｈ６→２－Ｃ４Ｈ６异构化反应机理，优化了基态势能面上反应物，过渡态，中间体和产物的几何构型，并对各驻点能量进行了零点能校准。结果表明该反应经历了一个１－甲基环丙烯生产产物比较两步氢迁移反应历程更易发生。     

Structural and Physicochemical Studies of [4-ClC6H4CH2NH3]4Li2P6O18·4H2O

The crystal structure of a new organic cation cyclohexaphosphate, [4-ClC ₆ H ₄ CH ₂ NH ₃ ] ₄ Li ₂ P ₆ O ₁₈ .4H ₂ O, is reported. It crystallizes in the triclinic system (space group P-1) with the following unit-cell parameters: a = 9.628(8), b = 12.801(9), c = 19.528(6) Å, α = 78.60(4)°, β = 83.00(5)°, β = 89.98(4)°, Z = 2, and V = 2341(3)Å ³ . The structure has been solved using direct methods and refined by least-squares analysis [R ₁ = 0.043, wR ₂ = 0.108]. The structure can be described as infinite anionic layers with composition of [Li ₂ (P ₆ O ₁₈ )(H ₂ O) ₄ ] ^{4 ?} and parallel to the ac plane. The organic groups are located in the accessible voids. The molecules are stabilized by O─H…O and N─H…O types of intermolecular hydrogen bonds in the unit cell in addition to Van der Waals forces.     

Critical temperatures,pressures, and densities for the mixtures CO2–C3H8, CO2–nC4H10, C2H6–C3H8, and C3H8–nC4H10

A simple method is developed to estimate mixture critical temperatures (T_c), pressures (P_c), and densities (ρ_c) as a function of overall composition (X) from near critical region experimental coexistence data. This three-step method is applied to four mixtures, CO₂–C₃H₈, CO₂–nC₄H₁₀, C₂H₆–C₃H₈, and C₃H₈–nC₄H₁₀. Isothermal liquid–vapor coexistence data, which includes temperature, vapor pressure, coexisting densities (ρ^ℓ and ρ^v), and coexisting compositions for the more volatile component (x₁^v and x₁^ℓ) are used. In the first step, the difference of the saturated liquid and vapor densities (ρ^ℓ−ρ^v) is fitted to an empirical function in ((P_c−P)/P_c) to obtain P_c. Then P/P_c and ((ρ^ℓ+ρ^v)/2ρ_c) are simultaneously fitted to functions of a polynomial in (X₁−(x₁^v+x₁^ℓ)/2) yielding estimates of ρ_c and X₁. Finally, the discrete estimated critical data points are fitted with an equation to provide a continuous representation of the critical lines. The method is successfully tested for the mixtures, CO₂–C₃H₈ and CO₂–nC₄H₁₀, for which there is a reasonable amount of isothermal data. The procedure is then applied to the mixtures, C₂H₆–C₃H₈ and C₃H₈–nC₄H₁₀, for which there are sparse data. For all four mixtures, the critical temperature line, T_c vs. X₁, matches literature values within ±0.5%. The critical pressure line, P_c vs. X₁, and critical density line, ρ_c vs. X₁, match literature values, in general, within ±2%.     

Synthesis and Structure of Antimony Complex Compounds [(4-N,N-Me2C6H4)3MeSb]I and [(4-N,N-Me2C6H4)3MeSb]2[Hg2I6]·2DMSO

Russian Journal of General Chemistry - It was first found that the alkylation of tris(4-N,N-dimethylaminophenyl)stibine with methyliodide leads to the formation of...     

The mechanism and kinetics of energy transfer processes in the Xe–CCl4–M (M=CH4, C2H2, C2H4, C2H6 C3H6 and C3H8) mixtures irradiated by xenon resonance light

The mechanism and kinetics of energy transfer from Xe(6s[3/2]₁) resonance state (E=8.44 eV) to selected hydrocarbon molecules have been investigated by XeCl(B–X) (λ_max=308 nm) fluorescence intensity measurements at stationary conditions in Xe–CCl₄–M systems. Steady-state analysis of the fluorescence intensity dependence on the xenon and M pressure at constant CCl₄ concentration shows that these process occur in the two- and three-body reactions: Xe(6s[3/2]₁⁰)+M→products, Xe(6s[3/2]₁⁰+M+Xe→products. The two- and three-body rate constants for these reactions have been found (see Table 1Table 1. Experimental parameters of Eq. (8)found by least square method in Xe–CCl₄–C₂H₂ and Xe–CCl₄–C₂H₄ systems for chosen xenon pressures in the range 25–150 Torr. Linear correlation coefficients (R) are also shown     

10.

Über das 2, 4, 6-Trichlor-3-Bromphenol und das 2-Chlor-4, 6-Dibromphenol     

Moritz Kohn  Fanny Rabinowitsch 《Monatshefte für Chemie / Chemical Monthly》1927,48(5-6):347-360

Ohne Zusammenfassung     

11.

Synthesis and structure of tetra-p-tolylantimony complexes [(4-MeC6H4)4Sb] 2 + [Hg2I6]2−, [(4-MeC6H4)4Sb] 2 + [HgI4]2−, [(4-MeC6H4)4Sb] 3 + [Sb3I12]2−, and [(4-MeC6H4)4Sb]+[ReO4]−     

V. V. Sharutin  V. S. Senchurin  O. K. Sharutina  A. P. Pakusina  O. A. Fastovets 《Russian Journal of Inorganic Chemistry》2011,56(4):558-570

Complexes [(4-MeC₆H₄)₄Sb] ₂ ⁺ [Hg₂I₆]^2? (I), [(4-MeC₆H₄)₄Sb] ₂ ⁺ [HgI₄]^2? (II), [(4-MeC₆H₄)₄Sb] ₃ ⁺ [Sb₃I₁₂]^2? (III), were synthesized by reactions of tetra-p-tolylantimony iodide with mercury iodide and antimony iodide, respectively. Tetra-p-tolylantimony perrhenate [(4-MeC₆H₄)₄Sb]⁺[ReO₄]^? (IV) was prepared from tetra-p-tolylantimony chloride and sodium perrhenate in acetone. Crystal structures of complexes I, II, and IV were determined by X-ray crystallography. Mercury and rhenium atoms have tetrahedral coordinations in these complexes. The Hg-I and Re-O distances in the structures of I, II, and IV vary within 2.7719(13)–2.7908(12)Å, 2.7028(3)–2.9163(3) Å, and 1.693(3)–1.744(3) Å, respectively. Antimony atoms in two crystallographically independent trinuclear centrosymmetric [Sb₃I₁₂]^2? anions of complex III have an octahedral environment. Each terminal SbI₃ fragment (Sb-I_t, 2.8265(9)–2.8333(10)Å) is bound to the central atom through tree bridging iodine atoms (Sb(2)-I_br, 3.2275(9)–3.3620(10)Å). The distances between the central Sb atom and bridging iodine atoms are much shorter (Sb(1)-I_br, 3.0153(6)–3.0316(6) Å; Sb(3)-I_br, 2.9926(6)–3.0074(6) Å).     

12.

[C2（C6H5COO）4（C3H4N2S）2]4 合成,晶体结构及性质研究   总被引：2，自引：0，他引：2  

《高等学校化学学报》1995,16(12):1837-1840

     

13.

The Synthesis and Characterization of [4-CH3OC6H4CH2NH3]4P2O7·6H2O     

A. Selmi  S. Akriche  M. Rzaigui 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2201-2211

Inorganic–organic hybrid compounds exhibit interesting properties in several application areas. In this regard, chemical preparation and characterization by X-ray diffraction, thermal analysis, and IR spectroscopy are given for a new organic cation diphosphate [4-CH₃OC₆H₄CH₂NH₃]₄P₂O₇·6H₂O. This later crystallizes in a C2/c unit cell with a = 38.238(6)Å, b = 6.453(1)Å, c = 16.942(7)Å; β = 97.60(4)°; Z = 4; and V = 4144(2)ų and D_x = 1.377 g·cm^?3. Its crystal structure has been determinated and refined to R = 0.044, using 7978 independent reflections. This atomic arrangement consists of inorganic layers built up from P₂O₇ ^4? anions and water molecules. On these layers, which are parallel to the (b, c) planes, the (4-CH₃OC₆H₄CH₂NH₃)⁺ cations are anchored through multiple hydrogen bonds.     

14.

Crystal Structure of Loliolide (5, 6,7a-Tetrahydro-6-hydroxy-4, 4, 7a-trimethyl-2 (4H)-benzofuranones)     

CHEN Jing-Yu  CHEN Jian-Min  XIAO Pei-Gen 《结构化学》1997,(5)

1INTRODUCTIONThetitlecompound,C,,H,,O,(mp:146～148'C),forthefirsttime,wasiso-latedfromClinopodiumpolycephalum(Vant-)byC.Y.WuetHsuancalled"DuanXueliu"inChinesethatisusedinfolkmedicineforthetreatmentofhaemorrhagiadisease[1i.Itsstructurehasalreadybeendeterminedt2ibymeansofUV,lR,NMRandchemicalsynthesis.Sinceloliolideappearedtohaveantitumoractivity"'andim-munosuppressiveactivity'#'inrecentyears,weaffirmedthestructurebyX-raydiffractionanalysis.2EXPERIMENTALApaleyellowtransparentcry…     

15.

Syntheses, Spectroscopic Properties and Crystal Structures of （2-Cl-C6H4CH2）3SnS2CN（C5H10） and （2-Cl-C6H4CH2）3SnS2CN（C4H9N）     

尹汉东  王传华  邢秋菊 《结构化学》2004,23(10):1127-1132

1 INTRODUCTION The chemistry of organotin(IV) complexes was extensively studied due to their biological activity and coordination chemistry[1～7]. More recently, phar- maceutical properties of alkyltin(IV) complexes with dithiocarbamate ligands have bee…     

16.

Synthesis and Crystal Structure of [Ni(H2O)6][Ni(H2O)2(C4H2O4)]·4H2O     

《Journal of Coordination Chemistry》2012,65(11):967-973

Reaction of a freshly prepared Ni(OH)_{2?2 x} (CO₃) _x ·yH₂O with maleic acid in H₂O at room temperature afforded [Ni(H₂O)₆][Ni(H₂O)₂(C₄H₂O₄)]·4H₂O, which consists of [Ni(H₂O)₆]²⁺ cations, [Ni(H₂O)₂(C₄H₂O₄)]^2? anions and lattice H₂O molecules. Ni atoms in cations are octahedrally coordinated and Ni atoms in anions are each octahedrally coordinated by bidentate chelating maleato ligands and two water molecules at trans positions. Cations and anions are interlinked by hydrogen bonds to form 1D chains, which are hexagonally arranged and connected by the lattice water molecules. When heated in a flowing argon stream, the compound decomposes, with complete dehydration being followed by dissociation of nickel maleate into NiO and maleic anhydride.     

17.

Synthesis, crystal structure, and thermal stability of [Mo2O4(μ2-O)(C6H4O2)2(H2O)] · (C8H9N2)2 · 2H2O     

X. J. Xu 《Russian Journal of Coordination Chemistry》2014,40(1):48-53

From hydrothermal treatment of benzene-1,2-diamine, pyrocatechol, and MoO₃ in acetic acid solution, a new compound, [Mo₂(μ₂-O)₂(C₆H₄O₂)₂(H₂O)] · (C₈H₉N₂)₂ · 2H₂O (I), constructed from pyrocatechol chelated dinuclear molybdenum units and 2-methylbenzimidazole has been synthesized. Single-crystal structure analysis reveals that the compound crystallizes in the monoclinic space group P2₁/c with a = 23.365(2), b = 7.2214(5), c = 19.3021(16) β = 97.929(4), V = 3225.6(5), Z = 4, M = 808.46, ρ_c = 1.665 g/cm³, μ(MoK _α) = 0.84 mm^?1, F(000) = 1608, the final R = 0.0622 and wR = 0.1484 for 7385 independent reflections with R _int = 0.0393. Interestingly, an in situ condensation between acetic acid and benzene-1,2-diamine has occurred, and the unexpected 2-methyl-1-H-benzo[d] imidazoles serve as counterions and N-H donors to form stable hydrogen-bond network in the crystal. Furthermore, intermolecular hydrogen bonds are found among the cations, anions and crystalline water molecules. The double nuclear molybdenum units are connected by O-H...O hydrogen bonds with the crystalline water molecules to form one-dimensional chains, and the chains are further joined together by N-H...O to form a quasi-two dimensional structure.     

18.

New 1D and 2D metal oxygen connectivities in Cu(II) succinato and glutarato coordination polymers: [Cu3(H2O)2(OH)2(C4H4O4)2] · 4H2O, [Cu4(H2O)2(OH)4(C4H4O4)2] · 5H2O and [Cu5(OH)6(C5H6O4)2] · 4H2O     

《Journal of Coordination Chemistry》2012,65(21):3420-3437

Two Cu(II) hydroxo succinates [Cu₃(H₂O)₂(OH)₂(C₄H₄O₄)₂]?·?4H₂O (1) and [Cu₄(H₂O)₂(OH)₄(C₄H₄O₄)₂]?·?5H₂O (2) and one Cu(II) hydroxo glutarate [Cu₅(OH)₆(C₅H₆O₄)₂]?·?4H₂O (3) have been prepared and structurally characterized by single crystal X-ray diffraction methods. They feature 1D and 2D copper oxygen connectivity of elongated {CuO₆} octahedra in “4?+?1?+?1” and “4?+?2” coordination geometries. Within 1, linear trimers of three edge-sharing {CuO₆} octahedra are connected into copper oxygen chains, which are bridged by the anti conformational succinate anions to generate 2D layers with mono terminally coordinating gauche succinate anions on both sides. The layers are assembled into a 3D framework by interlayer hydrogen bonds with lattice H₂O molecules distributed in channels. Different from 1, the principal building units in 2 are linear tetramers of four edge-sharing {CuO₆} octahedra. The tetramers are condensed into copper oxygen chains and the succinate anions interlink them into a 3D framework with triangular channels filled by lattice H₂O molecules. The {CuO₆} octahedra in 3 are edge-shared to form unprecedented 2D inorganic layers with mono terminally coordinating glutarate anions on both sides. Interlayer hydrogen bonding interactions are responsible for supramolecular assembly of the layers into a 3D framework with lattice H₂O molecules in the channels. The inorganic layers in 3 can be described as hexagonal close packing of oxygen atoms with the Cu atoms in the octahedral cavities. The title compounds were further characterized by elemental analyses, IR spectra and thermal analyses.     

19.

Molecular Interactions and Inclusion Phenomena in Substituted β-Cyclodextrins. Simple Inclusion Probes: H2O, C, CH4, C6H6, NH4 +, HCOO−     

Stanislaw Miertus  Vladimir Frecer  Emo Chiellini  Federica Chiellini  Roberto Solaro  Jacopo Tomasi 《Journal of inclusion phenomena and macrocyclic chemistry》1998,32(1):23-46

Using a simple molecular mechanics approach interaction energy profiles of simple probes (C, CH₄, C₆H₆, H₂O, NH₄ ⁺, and HCOO^-) passing through the center of the -CD ring cavity along the main molecular symmetry axis were first evaluated. Molecular Electrostatic Potential (MEP) values along the same path were also evaluated. The effect of the flexibility of the host -CD molecule together with solute-solvent (H₂O) interactions have been represented by averaging structures of MD calculations for -CD alone and -CD surrounded by 133 H₂O molecules. The effect of various substitutions of -CD has also been evaluated. Small symmetric hydrophobic probes (such as C, CH₄, C₆H₆) are predicted to form stable inclusion complexes with non-substituted and substituted -CDs, the probe position typically being near the cavity center. The stability of the inclusion complexes will increase with increasing size and aliphatic character of the probe. Small polar and charged probes (such as H₂O, NH₄ ⁺, HCOO^-) are predicted to prefer the interaction with the solvent (water) in the bulk phase rather than the formation of inclusion complexes with non-substituted and substituted -CDs. Guest–host interactions in the stable inclusion complexes with hydrophobic probes are almost entirely dominated by dispersion interactions. The MEP reaches magnitudes close to zero in the center of the non-substituted -CD ring cavity and in most of the studied substituted -CDs and shows maximum positive or negative values outside of the cavity, near the ring faces. Substitution of -CD by neutral substituents leads to enhanced binding of hydrophobic probes and significant changes in the MEP profile along the -CD symmetry axis.     

20.

Syntheses and crystal structures of two Cd(II) coordination polymers: one-dimensional chain [Cd(C4H6N2)2(C4H2O4)(H2O)2] n and two-dimensional sheet [Cd(C4H6N2)(H2O)(C4H4O4)] n  ·  n H2O     

《Journal of Coordination Chemistry》2012,65(24):2679-2686

Two new Cd(II) coordination polymers, [Cd(C₄H₆N₂)₂(C₄H₂O₄)(H₂O)₂] _n (1) (where C₄H₆N₂?=?2-methylimidazole, C₄H₂O₄?=?fumarate), and [Cd(C₄H₆N₂)(H₂O)(C₄H₄O₄)] _n ?·?nH₂O (2), (where C₄H₄O₄?=?succinates), have been prepared and structurally characterized by single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1 in a one-dimensional chain structure, in which carboxy is monodentate; a three-dimensional supermolecular network structure was formed through hydrogen bonding. In complex 2, the coordination geometry of the Cd atoms is a pentagonal bipyramid, and a two-dimensional sheet is formed though carboxyl group bridging. In 1 and 2, IR spectra indicate the presence of bridging carboxyl groups, confirmed by structure analyses.     

Über das 2, 4, 6-Trichlor-3-Bromphenol und das 2-Chlor-4, 6-Dibromphenol

Ohne Zusammenfassung     

Synthesis and structure of tetra-p-tolylantimony complexes [(4-MeC6H4)4Sb] 2 + [Hg2I6]2−, [(4-MeC6H4)4Sb] 2 + [HgI4]2−, [(4-MeC6H4)4Sb] 3 + [Sb3I12]2−, and [(4-MeC6H4)4Sb]+[ReO4]−

Complexes [(4-MeC₆H₄)₄Sb] ₂ ⁺ [Hg₂I₆]^2? (I), [(4-MeC₆H₄)₄Sb] ₂ ⁺ [HgI₄]^2? (II), [(4-MeC₆H₄)₄Sb] ₃ ⁺ [Sb₃I₁₂]^2? (III), were synthesized by reactions of tetra-p-tolylantimony iodide with mercury iodide and antimony iodide, respectively. Tetra-p-tolylantimony perrhenate [(4-MeC₆H₄)₄Sb]⁺[ReO₄]^? (IV) was prepared from tetra-p-tolylantimony chloride and sodium perrhenate in acetone. Crystal structures of complexes I, II, and IV were determined by X-ray crystallography. Mercury and rhenium atoms have tetrahedral coordinations in these complexes. The Hg-I and Re-O distances in the structures of I, II, and IV vary within 2.7719(13)–2.7908(12)Å, 2.7028(3)–2.9163(3) Å, and 1.693(3)–1.744(3) Å, respectively. Antimony atoms in two crystallographically independent trinuclear centrosymmetric [Sb₃I₁₂]^2? anions of complex III have an octahedral environment. Each terminal SbI₃ fragment (Sb-I_t, 2.8265(9)–2.8333(10)Å) is bound to the central atom through tree bridging iodine atoms (Sb(2)-I_br, 3.2275(9)–3.3620(10)Å). The distances between the central Sb atom and bridging iodine atoms are much shorter (Sb(1)-I_br, 3.0153(6)–3.0316(6) Å; Sb(3)-I_br, 2.9926(6)–3.0074(6) Å).     

The Synthesis and Characterization of [4-CH3OC6H4CH2NH3]4P2O7·6H2O

Inorganic–organic hybrid compounds exhibit interesting properties in several application areas. In this regard, chemical preparation and characterization by X-ray diffraction, thermal analysis, and IR spectroscopy are given for a new organic cation diphosphate [4-CH₃OC₆H₄CH₂NH₃]₄P₂O₇·6H₂O. This later crystallizes in a C2/c unit cell with a = 38.238(6)Å, b = 6.453(1)Å, c = 16.942(7)Å; β = 97.60(4)°; Z = 4; and V = 4144(2)ų and D_x = 1.377 g·cm^?3. Its crystal structure has been determinated and refined to R = 0.044, using 7978 independent reflections. This atomic arrangement consists of inorganic layers built up from P₂O₇ ^4? anions and water molecules. On these layers, which are parallel to the (b, c) planes, the (4-CH₃OC₆H₄CH₂NH₃)⁺ cations are anchored through multiple hydrogen bonds.     

Crystal Structure of Loliolide (5, 6,7a-Tetrahydro-6-hydroxy-4, 4, 7a-trimethyl-2 (4H)-benzofuranones)

1INTRODUCTIONThetitlecompound,C,,H,,O,(mp:146～148'C),forthefirsttime,wasiso-latedfromClinopodiumpolycephalum(Vant-)byC.Y.WuetHsuancalled"DuanXueliu"inChinesethatisusedinfolkmedicineforthetreatmentofhaemorrhagiadisease[1i.Itsstructurehasalreadybeendeterminedt2ibymeansofUV,lR,NMRandchemicalsynthesis.Sinceloliolideappearedtohaveantitumoractivity"'andim-munosuppressiveactivity'#'inrecentyears,weaffirmedthestructurebyX-raydiffractionanalysis.2EXPERIMENTALApaleyellowtransparentcry…     

Syntheses, Spectroscopic Properties and Crystal Structures of （2-Cl-C6H4CH2）3SnS2CN（C5H10） and （2-Cl-C6H4CH2）3SnS2CN（C4H9N）

1 INTRODUCTION The chemistry of organotin(IV) complexes was extensively studied due to their biological activity and coordination chemistry[1～7]. More recently, phar- maceutical properties of alkyltin(IV) complexes with dithiocarbamate ligands have bee…     

Synthesis and Crystal Structure of [Ni(H2O)6][Ni(H2O)2(C4H2O4)]·4H2O

Reaction of a freshly prepared Ni(OH)_{2?2 x} (CO₃) _x ·yH₂O with maleic acid in H₂O at room temperature afforded [Ni(H₂O)₆][Ni(H₂O)₂(C₄H₂O₄)]·4H₂O, which consists of [Ni(H₂O)₆]²⁺ cations, [Ni(H₂O)₂(C₄H₂O₄)]^2? anions and lattice H₂O molecules. Ni atoms in cations are octahedrally coordinated and Ni atoms in anions are each octahedrally coordinated by bidentate chelating maleato ligands and two water molecules at trans positions. Cations and anions are interlinked by hydrogen bonds to form 1D chains, which are hexagonally arranged and connected by the lattice water molecules. When heated in a flowing argon stream, the compound decomposes, with complete dehydration being followed by dissociation of nickel maleate into NiO and maleic anhydride.     

Synthesis, crystal structure, and thermal stability of [Mo2O4(μ2-O)(C6H4O2)2(H2O)] · (C8H9N2)2 · 2H2O

From hydrothermal treatment of benzene-1,2-diamine, pyrocatechol, and MoO₃ in acetic acid solution, a new compound, [Mo₂(μ₂-O)₂(C₆H₄O₂)₂(H₂O)] · (C₈H₉N₂)₂ · 2H₂O (I), constructed from pyrocatechol chelated dinuclear molybdenum units and 2-methylbenzimidazole has been synthesized. Single-crystal structure analysis reveals that the compound crystallizes in the monoclinic space group P2₁/c with a = 23.365(2), b = 7.2214(5), c = 19.3021(16) β = 97.929(4), V = 3225.6(5), Z = 4, M = 808.46, ρ_c = 1.665 g/cm³, μ(MoK _α) = 0.84 mm^?1, F(000) = 1608, the final R = 0.0622 and wR = 0.1484 for 7385 independent reflections with R _int = 0.0393. Interestingly, an in situ condensation between acetic acid and benzene-1,2-diamine has occurred, and the unexpected 2-methyl-1-H-benzo[d] imidazoles serve as counterions and N-H donors to form stable hydrogen-bond network in the crystal. Furthermore, intermolecular hydrogen bonds are found among the cations, anions and crystalline water molecules. The double nuclear molybdenum units are connected by O-H...O hydrogen bonds with the crystalline water molecules to form one-dimensional chains, and the chains are further joined together by N-H...O to form a quasi-two dimensional structure.     

New 1D and 2D metal oxygen connectivities in Cu(II) succinato and glutarato coordination polymers: [Cu3(H2O)2(OH)2(C4H4O4)2] · 4H2O, [Cu4(H2O)2(OH)4(C4H4O4)2] · 5H2O and [Cu5(OH)6(C5H6O4)2] · 4H2O

Two Cu(II) hydroxo succinates [Cu₃(H₂O)₂(OH)₂(C₄H₄O₄)₂]?·?4H₂O (1) and [Cu₄(H₂O)₂(OH)₄(C₄H₄O₄)₂]?·?5H₂O (2) and one Cu(II) hydroxo glutarate [Cu₅(OH)₆(C₅H₆O₄)₂]?·?4H₂O (3) have been prepared and structurally characterized by single crystal X-ray diffraction methods. They feature 1D and 2D copper oxygen connectivity of elongated {CuO₆} octahedra in “4?+?1?+?1” and “4?+?2” coordination geometries. Within 1, linear trimers of three edge-sharing {CuO₆} octahedra are connected into copper oxygen chains, which are bridged by the anti conformational succinate anions to generate 2D layers with mono terminally coordinating gauche succinate anions on both sides. The layers are assembled into a 3D framework by interlayer hydrogen bonds with lattice H₂O molecules distributed in channels. Different from 1, the principal building units in 2 are linear tetramers of four edge-sharing {CuO₆} octahedra. The tetramers are condensed into copper oxygen chains and the succinate anions interlink them into a 3D framework with triangular channels filled by lattice H₂O molecules. The {CuO₆} octahedra in 3 are edge-shared to form unprecedented 2D inorganic layers with mono terminally coordinating glutarate anions on both sides. Interlayer hydrogen bonding interactions are responsible for supramolecular assembly of the layers into a 3D framework with lattice H₂O molecules in the channels. The inorganic layers in 3 can be described as hexagonal close packing of oxygen atoms with the Cu atoms in the octahedral cavities. The title compounds were further characterized by elemental analyses, IR spectra and thermal analyses.     

Molecular Interactions and Inclusion Phenomena in Substituted β-Cyclodextrins. Simple Inclusion Probes: H2O, C, CH4, C6H6, NH4 +, HCOO−

Using a simple molecular mechanics approach interaction energy profiles of simple probes (C, CH₄, C₆H₆, H₂O, NH₄ ⁺, and HCOO^-) passing through the center of the -CD ring cavity along the main molecular symmetry axis were first evaluated. Molecular Electrostatic Potential (MEP) values along the same path were also evaluated. The effect of the flexibility of the host -CD molecule together with solute-solvent (H₂O) interactions have been represented by averaging structures of MD calculations for -CD alone and -CD surrounded by 133 H₂O molecules. The effect of various substitutions of -CD has also been evaluated. Small symmetric hydrophobic probes (such as C, CH₄, C₆H₆) are predicted to form stable inclusion complexes with non-substituted and substituted -CDs, the probe position typically being near the cavity center. The stability of the inclusion complexes will increase with increasing size and aliphatic character of the probe. Small polar and charged probes (such as H₂O, NH₄ ⁺, HCOO^-) are predicted to prefer the interaction with the solvent (water) in the bulk phase rather than the formation of inclusion complexes with non-substituted and substituted -CDs. Guest–host interactions in the stable inclusion complexes with hydrophobic probes are almost entirely dominated by dispersion interactions. The MEP reaches magnitudes close to zero in the center of the non-substituted -CD ring cavity and in most of the studied substituted -CDs and shows maximum positive or negative values outside of the cavity, near the ring faces. Substitution of -CD by neutral substituents leads to enhanced binding of hydrophobic probes and significant changes in the MEP profile along the -CD symmetry axis.     

Syntheses and crystal structures of two Cd(II) coordination polymers: one-dimensional chain [Cd(C4H6N2)2(C4H2O4)(H2O)2] n and two-dimensional sheet [Cd(C4H6N2)(H2O)(C4H4O4)] n · n H2O

Two new Cd(II) coordination polymers, [Cd(C₄H₆N₂)₂(C₄H₂O₄)(H₂O)₂] _n (1) (where C₄H₆N₂?=?2-methylimidazole, C₄H₂O₄?=?fumarate), and [Cd(C₄H₆N₂)(H₂O)(C₄H₄O₄)] _n ?·?nH₂O (2), (where C₄H₄O₄?=?succinates), have been prepared and structurally characterized by single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1 in a one-dimensional chain structure, in which carboxy is monodentate; a three-dimensional supermolecular network structure was formed through hydrogen bonding. In complex 2, the coordination geometry of the Cd atoms is a pentagonal bipyramid, and a two-dimensional sheet is formed though carboxyl group bridging. In 1 and 2, IR spectra indicate the presence of bridging carboxyl groups, confirmed by structure analyses.