多(三甲硅基)取代环戊二烯基二羰基钼环卡宾配合物的合成和结构  

Syntheses and Structures of Tris(Trimethylsilyl) Cyclopentadienyl Molybdenum Cyclic Carbene Complexes

作　　者：徐善生[1] 龚军芳[1] 周秀中[1] 张殿坤[2] 

机构地区：[1]南开大学化学系,天津300071 [2]南开大学元素有机化学研究所,天津300071

出　　处：《化学学报》1997年第5期480-485,共6页Acta Chimica Sinica

基　　金：国家自然科学基金;国家教委博士学科点基金资助课题

摘　　要：三(三甲硅基)环戊二烯在一缩二乙二醇二甲醚或四氢呋喃中经n-BuLi处理后,随之与Mo(CO)_6加热,生成相应的环戊二烯基碳基钼负离子锂盐[η~5{(Me_3Si)_3C_5H_(5-n)}Mo^-(CO)_3]Li^+(n=2,3)(1),同时观察到有脱硅基现象发生.1与X(CH_2)_3X在一缩二乙二醇二甲醚中反应,无论X=I或Br,均生成标题化合物[η~5-(Me_3Si)_nC_5H_(5-n)]Mo(CO)_2(CH_2)_2CH_2[X=I:n=3(2),n=2(3);X=Br:n=3(4),n=2(5)].1与X(CH_2)_3X的反应如在THF中进行,则只有当X=I时才能生成环卡宾钼配合物.以元素分析,IR,~1H NMR和^(13)C NMR表征了2～5的结构,并用X射线衍射测定了4的晶体结构.晶体属单斜晶系,空间群为P2_1/n,晶胞参数a=1.2611(3),b=1.2434(2),c=1.7095(6)nm.β=91.07(2)°,V=2.680(2)nm^3, D_c=1.563g·cm^(-3),Z=4.最终偏差因子R=0.062,R_w=0.054.Tris(trimethylsilyl)cyclopentadiene was treated with n - BuLi in diglyme or THF, followed by reaction with Mo(CO)6.The corresponding lithium salt of molybdenum anion [()5 -{(Me3Si)nC5H5-n} Mo(CO)3]- Li+, 1, (n=2,3) was formed. Meanwhile, desilylation was observed. The reaction of 1 with X(CH2)3X was carried out in diglyme,either X = I or Br.all gave the title complexes [X=I:n =3(2),n =2(3);X=Br:n=3(4),n=2(5)]. If the same reaction was carried out in THF, only when X = I, the cylic carbene complexes could be formed. The structures of 2~5 were characterized by elemental analyses, IR, 1H NMR and 13C NMR spectra. The crystal structure of 4 was determined by X- ray crystallography. The crystal is monoclinic,with space group P21/n ,a = 1.2611(3), b = 1.2434(2), c = 1.7095(6) nm,β = 91.07(2)°, V= 2.680(2)nm3,Dc= 1.563 g·cm-3,Z = 4.The final deviation factor R =0.062,Rw= 0.054.

关 键 词：环卡宾 钼配合物 晶体结构 脱硅基现象 卡宾 

分 类 号：O614.612[理学—无机化学]