摘要:

AbstractGuan‐fu base G is a new alkaloid isolated from root tuber ofAconitum coreanumLe'vl Raipaics. Guan‐fu base G methyliodide crystallizes in orthorhombic system, space groupD4/2‐P212121, with dimensions:a= 16.87Å,b= 16.93Å,c= 10.09Å;Z= 4. The three dimensional data were collected on a Phillips PW‐1100 four‐circle diffractometer with MoKaradiation.The structure was solved by heavy‐atom method and subsequently successive Fourier syntheses. The structure was refined by block‐diagonal matrix least squares methods toR= 0.0578 for 2848 reflexions. The absolute configuration was determined by computation of theRfactor for the two possible configurations using anomalous scat

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020102

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractA new kind of binuclear tungsten complex {W2[SC(NH2)NHCH2CHCH2]3Cl6} H2O was synthesized by mixing a concentrated hydrochloric acid solution of [W2Cl]3−with allylthiourea and investigated by X‐ray structural analysis. The crystal is monoclinic, belonging to the space group P21, with the following parameters:a= 8.496(1)Å,b= 18.760(2)Å,c= 8.591(1)Å, β = 91.36(1)' andZ= 2 withDc= 2.297 g·cm−3. The structure was solved by heavy atom method and difference Fourier synthesis and refined by full‐matrix least‐squares technique to a finalRfactor of 0.038 for 2812 independent reflections withI≥ 3σ(I).The result shows that in the structure each W atom forms an octahedral coordination with three Cl atoms and three bridging S atoms of the allylthiourea molecules. These two octahedra share a common face to form a binuclear complex with a very much shorter W‐W bond distance (2.443(1)Å), indicating a strong interaction between the two W atoms. Judging from the orientation of the thiourea ligand groups with respect to the W‐S bonds, the thiourea S atoms are coordinated to the two W atoms in different manners. It is noted that one of the two W atoms is located at the point of intersection of the three thiourea planes, while the other W atom is located quite apart from these thiourea planes with three W‐S bonds nearly perpendicular to e

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020103

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe title reaction gave three known compounds (2, 3 and 4) and two new compounds, CH3SCH2(CF2)2H (5) and I(CF2)2O(CF2)2SO3−S+(CH3)3(6). The structure of 6 was confirmed by X‐ray diffraction analysis. The crystals of 6 belong to monoclinic space group P21/C witha= 9.399,b= 15.651,c=10.934Å, β = 94.80° andz= 4. The structure was solved by heavy‐atom method and refined by block‐diagonal matrix least‐squares procedure to a finalRof 0.054 for 1999 independent observed reflexions.The SC bonds around the sulphur atom in trimethylsulphonium are pyramidal with the bond lengths of 1.814 Å, 1.800Å and 1.818 Å and the bond angles C‐S‐C of 101.06°, 101.52° and 102.53°. The distances of the sulphur atom in trimethylsulphonium to three oxygen atoms in the sulphonate radical are 3.79 Å, 3.64 Å and 3.34 Å respectively. These distances are out of the range of the normal S‐O bond length. The structure consists of trimethylsulphonium cations and 5‐iodo‐3‐oxa

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020104

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe composition of the coordination compound formed by the anti‐isomers of 2‐hy‐droxy‐4(5)‐substituted benzophenone oximes with copper was deduced to contain a ligand‐metal ratio of 2:1, based on the data of Job's and slope method as well as by the method of saturated extraction and elemental analysis.By the method of UV and IR spectroscopies and molecular weight determination the structures of the complexes were elucidated. As central ion, copper was linked with phenolic oxygen and oximidonitrogen by covalent and coordinated bonds respectively. Meanwhile, the oximido hydroxy group formed stronger intermolecular hydroxy bond with phenolic oxygen of another ligand molecule. The resulting molecule seemed to be in planar square co

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020105

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe29Si NMR study of aqueous solution of sodium silicate of mole ratio SiO2to Na2O equals one shows that the degree of polymerization of sodium silicate decreases with the decrease of the concentration, but the concentration of monosilicate anion increases, and that the lower the salt concentration, the faster is the rate of increase of the anionic concentration. The effect of SiO2/Na2O mole ratio and the concentration of sodium silicate on chemical shifts and spin‐lattice relaxation time, T1, of Si species and the effect of salt on degree of polymerization of sodium silicate in solution were also investigate

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020106

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe authors discuss the structural rule of different kinds of polyhedral boranes and propose a general topological formula for calculating the number of bonding molecular orbitals. In the case of single polyhedral boranes, results obtained from the formula are the same as those from the famous Wade rule. Futhermore, the formula can also be used to calculate the number of bonding molecular orbitals of joined‐type polyhedral boranes. We have also made some quantum chemistry calculations to verify the concept that the number of bonding molecular orbitals of boranes can be determined by considering only the corresponding boron polyhedral framework

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020107

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractIn this paper, the special effect of liquid crystal stationary phase is expressed in terms of ΔI, the difference of the retention index of probed solute between mesomorphic phase and isotropic phase. A series of compounds with different structures and polarities are selected as probed solutes for the investigation of their retention behavior on liquid crystal PBOB and MPBOB. According to the differences of ΔIof various solutes, the rule of special selectivity on liquid crystal is explaine

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020108

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractIn this paper, the photometric properties of the heteropolyacid ion‐associate Crystal Violet‐molybdophosphate in various media have been studied and its composition has been established as (C25H30N3)3· (PMo12O40) by means of spectrophotometry, elemental analysis and infrared absorption spectrophotometry. It has been proved that the photometric properties of the ion‐associate depend mainly upon the cation of the basic dye. We have also compared the suspension (or centrifugation) separation‐organic solvent dissolution method, the micelle solubilization method and the soluble polymer protectio

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020109

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractReduction of ethers containing various imino systems with sodium in boiling ethanol was shown to give different results, thus, β‐aryl substituted imino ethers can be reduced and cleaved, while β‐aliphatic imino ethers are not susceptible to sodium‐alcohol reductive fission. In the synthesis of β‐imino ethers it has been found that molecular sieve is a good condensation catalyst for the formation of highly hindered Sc

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020110

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractInfrared and Raman spectra ofO, O‐diethyl phosphorodithioic acid have been studied both at and below room temperature. The results show that the vibrations of P=S, P(‐O)2, P‐S and S‐H groups give multiple bands and the relative intensities of these bands vary as the temperature of the sample changes. According to the experimental results, we suggest that there are four rotational isomers ofO, O‐diethyl phosphorodithioic acid. Reasons for splitting the vibrational bands of these groups are also

ISSN:0256-7660    

DOI:10.1002/cjoc.19840020111

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY