SYNTHESIS of(η~5-C_9H_7)Ln(η~8-C_8H_8)·2THF AND CRYSTAL STRUCTURE OF(η~5-C_9H_7)Pr(η~8-C_8H_8)·2THF

The reaction of LnCl_3 with K _9H_7(C_9H_7=indenyl)andK_2C_8H_8(C_8H_8=cyclooctatetraene)in tetrahydrofuran(THF)give thecorresponding complexes(η~5-C_9H_7)Ln(η~8-C_8H_8)·2THF.The synthesis of(η~5-C_9H_7)Ln(η~8-C_8H_8)·2THF(Ln=Pr,Nd)and crystal structure of(η~5-C_9H_7)Pr(η~8-C_8H_8)·2THF are described.     

SYNTHESIS AND CRYSTAL STRUCTURE OF [(η~5-C_5H_5)_2NdCl·OC_4H_8]_2

All attempts to prepare light lanthanide dicyclopeutadienyt chloride failed,due to the disproportionation reaction. The crystal complex of [(η~5-C_5H_5)_2NdCl.OC_4H_8]_2 was successfully prepared by the reaction of NdCl_3·2C_4H_8O with cyclopentadienyl sodium (molar ratio 1:1.8)in tetrahydrofuran at room temperatureThe composition of the title compound was determined by the methods of elemental analysis, infrared spectroscopy and photoelectron spectroscopy. The crystal structure of [(η~5-C_5H_5)_2NdCl·OC_4H_8]_2 was determined from single crystal X-ray diffraction. Data were collected at-60℃ under dry nitrogen atmosphere.The complex crystallizes in the monoclinic space group P2_1/c,with Z=2. Lattice parameters are: a=8.201(3), b=21.589(6),c=8.596(3),β=109.10(3)°.The structure was solved by Patterson and Fourier techniques and refined by least-squares to a final conventional R=0.0636 for 1680 reflections. There are two Nd atoms in the dimeric unit which are bridged asymmetrically by the two chlori     

CRYSTAL STRUCTURE OF 18-TUNGSTODIVANADATE ANION IN Na_2H_2[H_2V_2W_(18)O_(62)].12H_2O

The structure of Na_2H_2[H_2V_2W_(18)O_(62)]12H_2O has been determined by x-rayanalysis.The crystals are trigonal,space group R3m,with cell parametersa=37.613(11),c=12.972(7)A,V=15901(13)A~3,and Z=9.The structure model wasrefined by full-matrix least square to R=0.065 for 1702 reflections with F>4σ(F).The existence of the[H_2V_2W_(18)O_(62)]~(4-)heteropolyanion in the crystals has beenconfirmed.It is composed of two VO_4 tetrahedra and eighteen WO_6 octahedralinked to gve the Dawson-type structure.     

THEORETICAL STUDIES ON CARBENES AND CARBENOIDS (Ⅳ) ——ISOMERIZATIONS AND DECOMPOSITIONS OF CARBENOIDS H_2C=CLiCl AND H_2CLiCl

The isomerizations and decompositions of carbenoids H_2C=CLiCl and H_2CLiCl have been studied by use of HF/STO-3G gradient method. Three equilibrium structures of H_2C=CLiCl were obtained, in which the linear structure has the lowest energy and the askew substituted structure was the next. It is found that the decomposition of H_2C=CLiCl undergoes a concerted FBW rearrangement and the inversion barrier of its askew substituted structure is 36 kJ/mol. For H_2CLiCl, the askew substituted structure, extending all valences of the carbon into a single hemisphere, is the lowest energy and its inversion barrier is 87 kJ/mol. The discussions on the factors concerned with the structural stabilities are given in this paper.     

CRYSTAL AND MOLECULAR STRUCTURE OF IPOHARDINE PICRATE, C_(15)H_(16)NO·C_6H_2N_3O_7

<正> INTRODUCTION. Ipomoea Hardwickii Hemsl (Ⅰ) belongs to Convolvulaceae, and its seed may be used as an anodyne. Ipoharine and Ipohardine were obtained by Reinickate method from the aqueous solution of Ⅰ. The structure of the title compound has been determined by X-ray crystal structure analysis. The structure of the cation (C_(15)H_(16)NO)~+ is reported here for the first time.     

THE FORMATION AND CRYSTAL STRUCTURE OF (η~5-C_5H_5)_3Nd·OC_4H_8 AND (η~5-C_5H_5)_3Pr·OC_4H_8

Under suitable reactant ratios without sublimation or reerystallization, single crystals of(η~5-C_5,H_5)_3 Ln-OC_4H_8(In = La, Pr, Nd) could be prepared by the reaction of cyclopentadienylsodium with respective lanthanide trichlorides in THF. Using low temperature technique wehave collected the X-ray data of single crystals of the title compounds at -60℃ under N_2and determined crystal structures. (η~5-C_5H_5)_3 Pr·OC_4H_8, [(η_5-C_5H_5)_3 Nd·OC_4H_8] recrystallizesin the monoclinic space group P2_1/n[P2_1/n] with unit cell parameters a = 8.406(3) [8.364(3)],b = 24. 510(9) [24.467(9)], c = 8. 284(3) [8.254(3)] A, β= 101.60(3) [101.42 (3)], D_c = 1. 62 [1.65]gem~(-3) for z = 4 [4]. Least-square refinement has led to a final R value of 0.056 [0.063],R_W = 0.049 [0.062]. The THF molecule is coordinated to the Pr [Nd] atom at a Pr-O [Nd-O]bond length of 2.16(1) [2.54(1)], A. The Pr-C (Cp) [Nd-C(Cp)] bond distances average 2.80(2) [2.78(2)] A. The title compounds are isostructaral with (η~5-C_5H_5)_3     

SYNTHESIS AND STRUCTURE OF TWO-ELECTRON HETEROPOLY BLUE K_2H_4SiMo(Ⅴ)_2Mo(Ⅵ)_(10)O_(40)·12H_2O WITH α-KEGGIN STRUCTURE

The single crystal of two-electron heteropoly blue with Si as the heteroatom and α-Keggin structure K_2H_4SiMo(Ⅴ)_2Mo(Ⅵ)_(10)O_(40)·12H_2O was obtained by electrolytic reduction. It crystallizes in a triclinic system with space group P , Mr=2117.73, a= 13.702(4), b=14.107(3), c=14.184(2) ; α=119.27(1), β=93.14(2), ;γ=110. 3(2)°, V=2154.29~3, Z=2, F(000)=1999, μ=36.39cm~(-1), Dc=3.26 g/cm~3. Final R factor is 0.0515. Mo(Ⅴ) is situated in two different edge-shared Mo_3O_(13) groups. The heteropoly blue was characterized by IR, UV, polarography, X-ray photoelectron spectra and ESR. All the results show that the structure of the heteropoly anion with Keggin structure remains unchanged basically in the process of reduction.     

CRYSTAL STRUCTURE OF BIS(η~5-CYCLOPENTADIENYL-η~6-ISOPROPYLBENZENE-IRON(II)) DODECAHYDRO-DODECABORATE(C_(14)H_(17)Fe~+)_2·B_(12)H_(12)~(2-)

<正> Introduction. It is well known that both cyclopentadienyl-aromatic sandwich complexes of metal and boronhydrides have special and interesting Structures. Recently we have studied the structures of some of the compounds which simultaneously contain the two Structural units, i. e. sandwich and borane polyhedron (Chen and Pan, 1983, Fu and Pan, 1982, Zhang et al., 1982). The present work is a continuation of our previous studies.     

CRYSTAL STRUCTURE OF AgSCN·C_5H_5N

<正> INTRODUCTION. The structure of the title compound has been determined as a part of our systematic studies on the structural chemistry of silver. CRYSTAL DATA. The compound AgSCN'C_5H_5N crystallized from a pyridine     

Gear-like array of (H_2O)_(12) as building blocks in one-dimensional supramolecular assembly

The preparation and crystal structure of complex Co(Hsae)_2·2H_2O (1,H_2sae=N-salicylidene-2-iminoethanol) are reported.X- ray analysis revealed that every six Co(Hsae)_2 forms a cyclic chip and every 12 water forms a novel gear-like cluster.Acting as building blocks,the gear-like water cluster and complex chip are connected in A-B fashion and extend into one-dimensional supramolecular chain.Hydrogen bond is the primary bridging force in the formation of supramolecular framework.     

Framework Structure of a Synthetic High Silica Zeolite --ZSM-39 from a C_2H_4(OH)_2-H_2O Mixed Solvent System

The structural analogy of clathrate synthesized with natural zeolite framework is well known. HPF_6·6H_2O and (CH_3)_4 (OH)·5H_2O are isostructural with sodalite,melanophlogite is isostructural with the 12 cubic gas hydrate and zeolite ZSM-39 with the 17 gas hydrate. The synthesis of ZSM-39 was first reported by Brace in 1981.Schleker and Meier also obtained the crystals of ZSM-39 with size<10μm and analyzed its crystal stucture by the powder X-ray diffraction.In 1984,Gies solved the crystal structure of dodecasil 3C(ZSM-39) synthesized from an aqueous system in space group F_(ds).In the present paper,we report the framework structure of the high silica zeolite—ZSM-39 obtained from the ethylene glycol-water mixed solvent system.     

CRYSTAL STRUCTURE OF BIS (η~5-CYCLOPENTADIENYL)(1,3-PROPANEDIYL-BIS(DIPHENYL-PHOSPHINE)-P,P')NICKEL(II) DODECAHYDEO-DODECABORATE (C_5H_5Ni(C_6H_5)_2PC_3H_6P-(C_6H_5)_2)_2~ ·B_(12)H_(12)~(2-)

<正> Introduction. Tertiary diphosphine-cyclopentadienyl-nickel(Ⅱ) complexes were first synthesized by Sato (Sato, et al., 1971), and their boronhydrides were prepared by Zhang (Zhang, et al., 1983). Here we report the crystal structure of the title compound in Order to correlate the reactivity of this type of compounds with their structures and bondings.     

ELECTRONIC ABSORPTION SPECTRA OF Cu(O_4H_4O_5)_2 ·2H_2O CRYSTAL

<正> The electronic absorption spectra of the'crystal of Cu(CtfH505) g-2H20 were measured. The experimental results were discussed quantitatively by using the ligand field theory and the radial wave function of nonfree copper(II). The electronic structure of the compound is in agreement with its crystal structure.     

CRYSTAL AND MOLECULAR STRUCTURE OF K(C_3H_(12)N_2)_2(HV_(10)O_(28_).8.5H_2O

<正> Preliminary information. Vanadium compounds plays an important role in catalysis since they have a property of easily changeable oxidation states. As a part of our study on vanadium compounds, the crystal structure of the title compound is reported, which is prepared by the reaction of (C_3H_(12)N_2)_2-V_2O_7, NaVO_3 with KOH in an aqueous solution.     

PLASMA POLYMERIZATION OF ACETYLENE/CO_2/H_2

A study has been made on the plasma polymerization of acetylene/CO_2/H_2 in a capacitively coupled RF plasma. The monomer mixture yielded a crosslinked film with light brown color. A kinetic study is reported for the plasma polymer ization of acetylene/CO_2/H_2. The effects of discharge power level and reactor geometry on the rate of polymer formation are reported. The structure of the plasma polymer is investigated by IR study.     

SYNTHESIS AND STRUCTURE OF A NEW TYPE OF COORDINA-TION COMPOUND OF Gd(Ⅲ) WITH H_2 CCH_2CH_2C(~+NH_2)C-HCOO-

<正> The crystal structure of gadolinium L-proline (Pro) complex [Gd2-(C5H9NO2)6 (H2O)6] (ClO4)6 has been determined. The complex crystallizes in the triclinic space group PI with following crystal data: a = 9. 906(3), b=13. 052(5), c = 13.703(5) A. α=109. 63(3), β=110.31(2), γ=100. 73(3)°, V=1470.3(9) A3.Mr=1710. 1, F(000) = 854,μ=26. 30 cm-1, Dc = 1. 931 g/cm3, Z=1.The structure was refined to the final R of 0. 048 for 3804 reflections. The structure is of one-dimensional chain, in which each gadolinium ion lies at the center of a distorted square antiprism of the eight oxygen atoms provided by four bridging carboxylate groups from four Pro ligands, a terminal carboxylate group from one terminal Pro ligand and three water molecules and the two neighbouring gadolinium ions are linked to each other through the two bridging carboxylate groups from the two Pro ligands. The prolines exist in the form of H2 CCH2CH2(+NH2)CHCOO-, and the complexions in the crystal are linked together by the net of hydrogen bo     

CRYSTAL STRUCTURE OF TRINUCLEAR MOLYBDENUM CLUSTER H(Mo_3O(OAc)_3Cl_6)·3H_2O

<正> INTRODUCTION. Reacting of MoCl_3·3H_2O with organic ligands to-synthesize di- and trinuclear molybdenum complexes is an interesting research area. We wish to report the crystal structure of the title compound. It is one of our research results on structural chemistry of di- and trinuclear molybdenum complexes. The title compound was synthesized by reacting of MoCl_3·3H_2O with CH_3COCl。     

THE CRYSTAL STRUCTURE OF Mo_203[S_2P(OC_2H_5)_2]_4

<正> Introduction. In an attempt to synthesize Mo cluster compounds from the high-valenced Mo compounds in P_2S_5/EtOH-HC1 system we have obtained a brownblack rhombohedral crystal. The composition of it Mo_2O_3[S_2P(OC_2H_5)_2]_4 has been confirmed by X-ray single crystal structure determination, which reveals that the crystal structure is different from that by Knox, J. R. & Prout, C. K. (1969).     

Synthesis,Structure and Characterization of a New Complex: [Mn(C_6H_(12)N_4)_2(H_2O)_4][Mn(H_2O)_6][SO_4]_2·6H_2O

A novel complex,[Mn(C_6H_(12)N_4)_2(H_2O)_4][Mn(H_2O)_6][SO_4]_2·6H_2O,was synthesized and hexagonal single crystals with centimeter-scale sizes were obtained by the method of solvent evaporation.It was characterized by elemental analysis,infrared spectrum,thermogravimetric analysis and X-ray single-crystal diffraction.The complex belongs to triclinic crystal system,space group P■ with a=9.3390(8),b=13.3520(13),c=16.3207(13)?,α=100.7160(3)°,β=90.1020(10)°,γ=109.9490(5)°,V=1874.9(3)?~3,Z=2,D_c=1.542 g/cm~3,M_r=870.64,μ=0.876 mm~(-1),T=293(2) K,F(000)=916 and S=0.990.The crystal structure determination displayed a distorted octahedral geometry around the manganese atom,which is bound to two nitrogen atoms from hexamethylenetetramine,acting as monodentate ligands,and to four aqua ligands.Variable-temperature magnetic measurements of the complex indicate the presence of weak antiferromagnetic interaction between manganese centers.     

THEORETICAL STUDIES ON THE STRUCTURES AND REACTIVITY OF SILYLENOIDS (Ⅰ)——STRUCTURES AND ISOMERIZATION OF SILYLENOID H_2SiLiCl

The structures of silylenoid H_2SiLiCl have been studied by RHF/3-21G gradient method. Three equilibrium states and two isomerization transition states are located. The electronic energy, Mulliken populations, dipole moments and frontier molecular orbitals (FMO) of every structure and the isomeric barriers are also given and analyzed. Further single point calculations on the 3-21G optimum geometries were performed using 6-21G basis set. The calculations show that three-membered ring structure of H_2SiLiCl is the most stable and detectable, and the "classical" tetrahedral form is not the local minimum on the potential energy surface.