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The methylation of tin(II) [Sn(II)] by iodomethane (CH3I) under environmental conditions has been further demonstrated by a 13C carbon isotope tracer method. Methylation products are mainly monomethyltin, and very small amounts of dimethyltin. The reaction of Sn(II) and CH3I was investigated at pH 2, 4, 6, 8, 10 and salinity (S) 8, 15, 22, 28, 35%; it has been found the reaction was affected by pH and salinity, the tin methylation activity being highest at about pH 6 and S = 28% . The methylation reaction is first-order for both CH3I and Sn(II), and the rate equation has been obtained as follows: . 相似文献
13.
钯催化下有机锡化合物的偶联反应在碳-碳键形成过程中的应用 总被引:2,自引:0,他引:2
本文述评了最近几年来钯催化的有机锡化合物与有机亲电试剂的交叉偶联反应在有机合成中用于碳-碳键形成的主要研究成果。主要讨论了直接交叉偶联反应,CO或烯键插入的交叉偶联反应和机理。 相似文献
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15.
Chen Xiao-Ming Wu Yu-Luan Tong Ye-Xiang Sun Ziming David N. Hendrickson 《Polyhedron》1997,16(24):1041
A novel tetranuclear terbium(III) complex [Tb4(OH)4(pybet)6(H2O)8][Tb4(OH)4(pybet)6(H2O)7 (NO3)](ClO4)14·6H2O has been synthesized and shown by X-ray crystallography to have a cubane-like Tb4(μ3-OH)4(μ2-carboxylato-O,O′)6 core. The ligand pybet is pyridinoacetate, C5H5+N-CH2CO2−. Magnetic susceptibility data were measured for this Tb4 complex in the range of 2.0–320 K and in fields of 1.0 G to 50.0 kG. It is concluded that either there is very weak antiferromagnetic exchange interaction (J = −0.015 cm−1) or there is a small crystal-field splitting of the 7F6 TbIII ground state. 相似文献
16.
A high-performance thin-layer chromatographic (HPTLC) method is described for the determination of tributyltin compounds (bis(tri-n-butyltin) oxide, TBTO, and tri-n-butyltin naphthenate, TBTN) and their degradation products (dibutyltin and monobutyltin compounds). The organotin compounds are extracted from wood with ethanol containing 0.5% (v/v) of hydrochloric acid and the separation of the defferent kinds of organotin compounds is achieved by thin-layer chromatography. The sample spots are measured using a scanning densitometer after decomposing the organotin compounds to inorganic tin by ultraviolet irradiation and visualization of the spots with pyrocatechol violet. Applications of the method to detection and quantification of organotin compounds in preservative solutions, in recently impregnated wood, and in wood samples from five-year-old window frames are described. 相似文献
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The hexamolybdenum cluster complex [Mo6(3-Cl)8(O2CMe)6]2–, 1 was isolated as the Bu4N+ salt in 71% yield from the reaction of (Bu4N)2[Mo6(3-Cl)8Cl6] with AgO2CMe in CH2Cl2 solvent. The compound was characterized by single crystal X-ray diffraction analysis. The cluster contains an octahedral arrangement of six molybdenum atoms with eight chloride ligands bridging the eight trianglar faces and six carboxylate ligands terminally coordinated through one oxygen atom to each of the six molybdenum atoms. Crystal data: space group =P21/n,a=10.713(3)Å,b=14.43(1)Å,c=21.919(4)Å, =94.37(2)°,Z=2, 1965 reflections,R=0.036. 相似文献
19.
Dan M.J. Doble Richard D. Kay Colin H. Benison Alexander J. Blake Xiang Lin Claire Wilson Martin Schröder 《Journal of inclusion phenomena and macrocyclic chemistry》2001,41(1-4):23-30
Reaction of tris-(2-aminoethyl)amine (tren) andthe sodium salt of an -ketocarboxylic acid, typically sodium pyruvate, affordsin the presence of a lanthanide ion aseries of complexes and aggregates includingmononuclear, cyclic tetranuclear and polymerspecies of [L1]3- ([L1]3-=N[CH2CH2N=C(CH3)COO-]3).The aggregation of these and related d-block elementcomplexes with Na+ ions leadsto the formation of polymeric materials, and thefactors influencing the formation and controlof these various aggregation states are discussed.Metal cations also template the aggregationof the fragment [Ni(L2)] ([L2]2- =CH2[CH2N = C(CH3)COO-]2)to give, in high yield, the polynuclearaggregates {[Ni(L2)]6M}x+(M = Nd, Pr, Ce, La, x = 3; M = Sr, Ba, x = 2). The structures of{[Ni(L2)]6M}x+ show aninterstitial twelve co-ordinate, icosahedralcation Mx+ encapsulated by six [Ni(L2)]fragments. In the presence ofNa+, aggregation of [Ni(L2)] fragments affords {[Ni(L2)]9Na4(H2O)(MeOH)(ClO4)}3+ thestructure of whichshows four Na+ ions templating the formation ofa distorted tricapped trigonal prismatic[Ni(L2)]9 cage. Thus, control overconstruction of various polynuclear cages viaself-assembly at octahedral junctions can beachieved using main group, transition metaland lanthanide ion templates. 相似文献
20.
固相微萃取参数选择及其对有机锡分析的影响 总被引:1,自引:0,他引:1
固相微萃取是一种新型的、不断发展和完善的样品前处理方法,它与其它技术联用可对多种样品基体中挥发、半挥发性有机化合物进行测定。目前,该技术在毒性金属有机化合物中的应用很少。本文分析参数选择对固相微萃取的影响的同时,还对其在有机锡化合物分析中的应用作了综述。 相似文献