摘要:

AbstractBased on the various thermodynamic models for concentrated electrolyte and nonelectrolyte solutions, the correlation equations of activity coefficeints and methods of solubility prediction for ternary and quarternary systems have been developed. Only a few of experimental data are needed to calculate the interaction parameters. This method can be used to calculate the solubilities of the components for a given concentration of the unsaturated ones, the predicted solubilities agree with experimental data quite well.

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040402

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractReaction of Et4NI, NaSCH2CO2Et and Mo(CO)6in CH3CN affords a new dinuclear molybdenum (0) complex, [Et4N]2[Mo2(CO)8(SCH2CO2Et)2] (1). Electrochemistry and reactivity investigation indicate that 1 undergoes an interesting two‐electron oxidation in a single step (‐0.43 V) and a substitution of its carbonyls by coordinating solvents resulting in two kinds of Mo(I)‐complexes, Mo2(CO)8(SCH2CO2Et)2and (Mo2(CO)6SCH2CO2Et)2(CH3CN)2.vC=O andvMo‐CO have been assigned. The crystal and molecular structure has been determined from three‐dimensional X‐ray data. 1 crystallized in the triclinic, space group\documentclass{article}\pagestyle{empty}\begin{document}$$ P\bar 1 $$\end{document}witha=10.362(1),b=10.391(1),c= 10.815(2)Å; α=91.64(2)°, β=100.07(2)°, γ=114.46(1)°;Z=1;R=4.8% for 2975 reflections withI>3σ(I). Nonbonding of Mo … Mo [3.939(1)Å] and the configuration of MoS2Mo unit in 1 are very different from those in related Mo(I)‐product. These results confirm our previous speculation that the two‐electron character derives from creation or cleavage of a metal‐metal single bond coupled with structural rearrangement in

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040403

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe synthesis and crystal structure of novel trinuclear molybdenum cluster compound with somewhat “loose” coordination site {Mo3(μ3‐S)(μ‐S)3[S2P(OEt)2l4ṁ P(C6H5)3} ṁ (0.86 CH2C12) have been reported. The cluster crystallizes in the space group\documentclass{article}\pagestyle{empty}\begin{document}$$ P\bar 1 $$\end{document}with two molecules in a unit cell whose parameters area=10.472(4),b=14.375(2),c=21.695(3)Å; α=74.04(1)°, β=76.50(2)°, γ=72.22 (2)°,V=2950Å3andDo=1.693 g ṁ cm−3. On the basis of 4840 independent reflections withI≥2σ(I), the structure was solved by heavy atom method and Fourier method and refined by full‐matrix least‐squares techniques to a finalR=0.058.The distances between Mo atoms in this cluster are 2.731(1), 2.748(1) and 2.753(1)Å respectively. The meat value of Mo—Mo bond lengths is slightly shorter than those in other trinuclear Mo clusters with “loosely coordinated” site. In addition, the PPh3ligand is loosely coordinated to one Mo atom in direction opposite to the μ3‐S with Mo—P bond length of 2.647(3)Å. This is different from the other structurally analogous clusters, in which the loosely coordinated ligand istransto μ2‐S. A summary of M

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040404

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

Abstractπ‐Cyclopentadienyl(dicarbonyl)(phenylcarbyne)rhenium‐tetrabromoborate, [π‐C5H5(CO)2‐ReCC4H5]BBr4(3), at low temperature reacts with (μ‐phenylthio) (μ‐thiolato)hexacarbonyldiiron anion, (μ‐C6H5S) (μ‐LiS)Fe2(CO)6(2), to give π‐cyclopentadienyl (dicarbonyl){phenyl[(μ‐phenylthio)hexacarbonyldiiron (μ‐thio)] carbene} rhenium, π‐C5H5(CO)2ReC(C6H5)(μ‐S)(μ‐C6H5S)Fe2(CO)6(4). The complex 4 was identified by elemental analyses, IR,1H NMR and mass spectra, and finally confirmed by its single crystal X‐ray structure determination. The results from spectroscopic experim

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040405

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe electron impact (ED mass spectra of fourteen macrocyclic crown ether‐lactone (involving aliphatic and aromatic groups) were reported, and some typical EI fragmentation patterns were discussed in detail with the aid of exact mass measurement, linked scan and defocussing technique. The features of the field desorption (FD) mass spectra of ten compounds were also summarize

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040406

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe15N chemical shift have been measured for α‐15N‐labelled phenylazo‐2‐naphthol and its lithium complex. The change of the15N chemical shift on coordination of the azo nitrogen to lithium appears to be related to those of protonation of the same nitrogen. The chemical shifts of azo form and hydrazone form have been calculated according to the weighted δNand1JNHof different fractions. It is concluded that there is a bond formation between Li an

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040407

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractVarious metal (Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Sn, La) ferrocyanides and ferricyanides may be considered as a multibond activation model of bimetal coordination, since CN−acts as a typical ambident ligand bonded at the two ends with two metal ions. In accordance with hydrogenation reactions of CN−taking place during thermal decomposition in hydrogen, the activation effect of bimetal coordination and the mechanism of hydrogenation reaction of CN−are discussed from the viewpoint of the crystal structure and the electron structure of the complexes. The activation degree of CN−bonded with various metal ions has been investigated. It was found that the temperature at which the triple bond of CN−breaks with top speed to evolve NH3correlates closely with the standard electrode potential, anddelectron configuration of the m

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040408

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe title compound has been synthesized by the reaction of α‐dithionaphthoic acid with CuCl2in pyridine or by recrystallizing Cu4(α‐C10H7CSS2)4ṁ 1/2CS2in a mixture of pyridine and alcohol.The structure of the title compound is determined by a single‐crystal X‐ray diffraction analysis. The crystal belongs to triclinic space group\documentclass{article}\pagestyle{empty}\begin{document}$$ C_2^1 - P1 $$\end{document}with unit cell parameters:a=7.085(2)Å,b= 8.672(3)Å andc=13.598(5)Å;a=92.40(3)°, β=102.59(4)° and γ=105.67(4)°;V=780.6Å2;Z=1. The structure was refined toR=0.058 for 2390 reflections.The molecule of the title compound sits on a center of symmetry. The shorter Cu—Cu bond length (2.606Å) shows considerable interaction between copper atoms. If the Cu—Cu interaction is ignored, the neighbouring S and N atoms are coordinated to copper atom in a configuration

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040409

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe characteristics of photo, thermal and doping isomerizations of polyacetylene were discussed. A new biradical mechanism for photo and thermal isomerizations is proposed, which is consistent with the ESR results. The CNDO/2 and INDO molecular orbital calculation results show that the mechanism is energetically the most favorable. The reliability of applying general semi‐empirical MO methods in polymers is estimated and showed to be valuable in predicting propertie

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040410

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThis article described the preparation and the protection of 3′‐DMP and dihydrouridine (Dr) as well as the synthesis of four oligoribonucleotides composed of them.DMP and Dr were obtained by hydrogenation of 3′‐UMP and Ur under acidic conditions in the presence of platinum dioxide. They were monomethoxytritylated and benzoylated to (MeOTr)‐Dbzpand (MeOTr) Dbzs, respectively. The latter was converted to Dbzs, by demonomethoxytritylation.The oligoribonucleotides containing DMP or Dr—ApGpD, DpApG, ApGpDpC and ApGpDpCpGpG were synthesized via phosphodiester approach and DCC was used as condensing reagent. DpApG was also synthesized via phosphotriester approach and TPST, MSTe, MSNI and MSNT were used as condensing reagents for a preliminary comparison of the coupling yields.These synthetic oligoribonucleotides were checked for purity and nucleotide sequences as usual. ApGpDpCpGpG and DpApG had been used for enzymatic synthesis of ApGpDpCpGpGpDpApG, which had been in turn successfully used for the total syntheses of the 5′‐half molecule and the whole molecule of yea

ISSN:0256-7660    

DOI:10.1002/cjoc.19860040411

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY