η~6-[三(三甲基硅基)苯基硅烷]三羰基铬类化合物的合成及其分子内硅硅键与金属铬之间相互作用的理论研究  

Synthesis of η~6-[Tris( trimethylsilyl) phenylsilane] tricarbonylchromium Complexes and Theoretical Studies on the Possible Interaction of Intermolecular Si—Si Bonds and Chromium Centers

作　　者：吕浩挺 刘婷婷[1] 张明涛[1] 刘洁[1] 孙怀林[1] 

机构地区：[1]南开大学化学系,化学与工程协同创新中心,天津300071

出　　处：《高等学校化学学报》2014年第11期2341-2345,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20834002);天津市自然科学基金(批准号:08JCZDJC21600);高等学校博士学科点专项科研基金(批准号:20090031110012)资助~~

摘　　要：采用三(三甲基硅基)苯基硅烷p-R(Me3Si)3SiC6H4与六羰基铬在加热条件下反应,制得了相应的η6-[三(三甲基硅基)苯基硅烷]三羰基铬化合物{η6-[(Me3Si)3SiC6H4R]Cr(CO)3(R=H,p-Me,p-MeO)}.利用核磁共振波谱、红外光谱和元素分析等手段对产物进行了表征,并利用单晶X射线衍射法测定了化合物η6-[(Me3Si)3SiC6H4R]Cr(CO)3(R=H)的分子结构.在此基础上,对其分子内硅硅键与金属铬之间可能的相互作用进行了考察,发现在加热条件下硅硅键不能被分子内过渡金属活化.利用密度泛函理论(DFT)对预测的硅硅键活化过程进行了计算,发现反应可能的中间体、过渡态及最终产物均具有较高能量,导致反应在动力学和热力学上均不可行.这一结果表明,分子内硅硅键被过渡金属活化的现象在η6-苯基金属化合物体系中难以发生.Intramolecular Si—Si bond activation by transition metals has been widely found in transition metal complexes with polysilanyl substituted η4- and η5-ligands,but such activation in η^6phenyl complexes keeps unknown. In this study, η^6[tris（ trimethylsilyl） phenylsilane ] tricarbonyl chromium complexes,η^6[（ SiMe3）3SiC6H4R]Cr（ CO）3（ R = H,Me and MeO）,were synthesized by reaction of tris（ trimethylsilyl） phenylsilane,p-R（ Me3Si）3SiC6H4with hexacarbonylchromium in diethylene glycol dimethyl ether. The products were characterized by1 H NMR,13 C NMR,IR spectra and elemental analyses. The molecular structure of η^6[（ SiMe3）3SiC6H4R]Cr（ CO）3（ R =H） was determined by the X-ray diffraction method. The possibility of the Si—Si bond activation by the intramolecular chromium center was examined experimentally. The results showed that the Si—Si bonds in the complexes were stable under thermal conditions. Density functional theory（ DFT） calculation of possible Si—Si bond activation processes indicated that all the reaction intermediates and transition states had such high energies that the Si—Si bonds were unable to be activated by the intramolecular chromium center. These results demonstrated that Si—Si bond activation should be difficult to take place in polysilanyl substituted η^6phenyl transition metal systems.

关 键 词：硅硅键 羰基铬 η6-苯基络合物 X射线衍射 密度泛函理论计算 

分 类 号：O626[理学—有机化学]