CAJ | 학술논문

采用密度泛函理论方法在B3LYP/6-311G**水平研究了9-硅蒽和9-锗蒽与烯烃的杂Diels-Alder反应的微观机理、势能剖面，考察取代基对反应势能剖面的影响．计算结果表明，所研究反应均以协同非同步的方式进行，且Si（ Ge）-C键总是先于C-C键形成．乙烯分子中C原子上的苯基取代基在热力学上对反应不利，但在动力学上的影响取决于产物中苯基与Si（Ge）原子之间的相对位置．9-硅（锗）蒽分子中Si（Ge）原子上的2，4，6-三甲基苯基取代基在热力学和动力学上均对反应不利．
채용밀도범함이론방법재B3LYP/6-311G**수평연구료9-규은화9-타은여희경적잡Diels-Alder반응적미관궤리、세능부면，고찰취대기대반응세능부면적영향．계산결과표명，소연구반응균이협동비동보적방식진행，차Si（ Ge）-C건총시선우C-C건형성．을희분자중C원자상적분기취대기재열역학상대반응불리，단재동역학상적영향취결우산물중분기여Si（Ge）원자지간적상대위치．9-규（타）은분자중Si（Ge）원자상적2，4，6-삼갑기분기취대기재열역학화동역학상균대반응불리．
The mechanism and potential energy surface of the hetero-Diels-Alder reactions of 9-silaanthracene or 9-germaanthracene with alkenes were investigated using density functional theory ( DFT) at the B3LYP/6-311G**level and the influences of some substituents on the potential energy surface were explored .The obtained results were com-pared with those of the corresponding reactions of silabenzene or germabenzene .The results show that all reactions oc-cur in a concerted but nonsynchronous way and the formation of Si ( Ge)-C bond always keeps ahead the formation of C-C bond.The phenyl group at C atom of ethylene molecules is not in favor of the hetero -Diels-Alder reactions ther-modynamically , however , its influence on the kinetic properties of the reaction are determined by the relative position of phenyl with Si(Ge) atom in products.The mesityl substituent at Si (Ge) atom of 9-silaanthracene or 9-germaan-thracene molecules has an unfavorable effect on the reactions both thermodynamically and kinetically .