二{氧合—二茂铁基丙烯酸二正丁基锡(Ⅳ)} 配合物的晶体结构及溶液中的配位互变平衡机理  

Crystal Structure of Bis{oxo—bis[3一ferrocenylacrylate di—n—butyltin(1V)]}and Mechanism of Coordination Tautomeric Equilibrium in Solution

作　　者：陶家洵[1] 李旭宇[1] 卢文贯[2] TAO Jia-Xun;LI Xu-Yu;LU Wen-Guan(Depnrtmunt of Chemistry,Tsinghua Universuy,Beijing,100084;Department of Chemistry.Shaoguan Unisersuy,Shaoguan.512005)

机构地区：[1]清华大学化学系,北京100084 [2]韶关大学化学系,韶关512005

出　　处：《化学学报》2001年第4期538-543,共6页Acta Chimica Sinica

摘　　要：测定了配合物{[(n-Bu)_(2)Sn(FcCH=CHCO_(2))]_(2)0}_(2)(Fc=Ferrocenyl)的晶体结构。它属三斜晶系,空间群P1,晶胞参数α=1.3943(3)nm,b=1.4635(3)nm,c=1.2792(3)nm,α=94.32(3)°,β=116.27(3)°,γ=109.08(3)°,Z=2,V=2.1362(3)nm^(3),Dc=1.542g/cm^(3),F(000)=1004.最终偏差因子R=0.401,RW=0.1076,该分子中存在内环锡和外环锡配位单元,锡原子均形成具有假六配位的单加帽畸变三角双锥配位构型。Sn2O2中心环与丙烯酸酯基茂环等共轭体系之间的相互未能共平面,配合物中四个羧基配体划分为两类:两个为桥式双齿配体(μ-COO),跨接于一个内环锡和一个外环锡;另两个仅以单齿配位方式各连接一个外环锡。根据核磁共振谱信息表明分子在溶液中存在着配位互变异构体之间的交换。我们提出振动模式的假说,认为可能是羧酸脂基氧在其平面内快速摇摆建立了动态平衡之故。The crystal structure of the title complex has been determined.The crystal is>pace Pi with parameters:a=1.3943(3)rm.b=1.4635(3)nm.v'=1.2792(3)nm,a=94.32(3)°,3=1I6.27(3)°,y=109.08(3)°.Z=2,V=2.1362(8)nm',D,=1.542 g/cm',F(000)=1004,and the structure is refined to final R=0.0401.Ru=0.1076.Fuur carboxylate ligands are divided intn two types.Two of the carboxylate ligands are Lidentate(pe-C00)and bridging each pair of endo-and exo-ryclic tin atoms hy using both oxypen atoms.The others are monodentale and coordinate each exo-cyclic tin atom.Both endo-and exo-cyclic tin atoms ar all five-coordination with coordination geometry of monocapped distorted trigonal bipyramid.Two conjugate systens(acryloxy group and Cp ring)can not be coplanar with the central endo-eyclic Sn2O2 unit.The NMR data indicatr the existence of a dynamic process of the carboxylie coordination tautomers.Comparing the crystal i[(n-Bu):Sn(FcCO_)]O¡₂*4ÇH。(A)with|[(n-Bu)₂Sn(FcC02)]2Oiz(B),we put forward a waggling merhanism to explain this phenomenon,namely,the oxygen atoms of carboxylie groups vacillate quickly within the plane of their carboxylic groups.This is owing to the fluctuations of plectmn cloud to result in re-distribution or re-adjustment of Sn-0 bonds considrring completely both the strong and weak interactions brtween Sn ators and O atoms rather than the internal rotation about the Sn--O(carboaylic)bonds.

关 键 词：二有机锡 3一二茂铁垂丙烯酸酯 晶体结均 配位互变 动态学机理 

分 类 号：O614.432[理学—无机化学]