CAJ | 학술논문

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。
채용삼(삼갑기규기)분기규완p-R(Me3Si)3SiC6H4여륙탄기락재가열조건하반응,제득료상응적η6-[삼(삼갑기규기)분기규완]삼탄기락화합물{η6-[(Me3Si)3SiC6H4R]Cr(CO)3(R=H, p-Me, p-MeO)}。이용핵자공진파보、홍외광보화원소분석등수단대산물진행료표정,병이용단정X사선연사법측정료화합물η6-[(Me3Si)3SiC6H4R]Cr(CO)3(R=H)적분자결구。재차기출상,대기분자내규규건여금속락지간가능적상호작용진행료고찰,발현재가열조건하규규건불능피분자내과도금속활화。이용밀도범함이론( DFT)대예측적규규건활화과정진행료계산,발현반응가능적중간체、과도태급최종산물균구유교고능량,도치반응재동역학화열역학상균불가행。저일결과표명,분자내규규건피과도금속활화적현상재η6-분기금속화합물체계중난이발생。
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 η6-phenyl complexes keeps unknown. In this study, η6-[ tris ( trimethylsilyl ) phenylsilane ] tricarbonyl chromium complexes,η6-[ ( SiMe3 ) 3 SiC6 H4 R] Cr( CO) 3( R=H, Me and MeO) , were synthesized by reaction of tris( trimethylsilyl) phenylsilane, p-R ( Me3 Si ) 3 SiC6 H4 with hexacarbonylchromium in diethylene glycol dimethyl ether. The products were characterized by 1 H NMR, 13 C NMR, IR spectra and elemental analyses. The molecular struc-ture ofη6-[ ( SiMe3 ) 3 SiC6 H4 R] Cr( CO) 3( R=H) was determined by the X-ray diffraction method. The possi-bility 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 interme-diates 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 η6-phenyl transition metal systems.