Ce+XF3(X=N,P和As)反应产物的量子化学研究

Quantum Chemical Studies on the Products of Ce+XF3(X=N,P and As)Reactions

采用ab-initio方法研究了Ce+XF3(X=N,P和As)反应的可能产物(CeXF3、XCeF3、FXCeF2和F2XCeF)的平衡几何结构和能量,并使用AIM、自然布居电荷(NPA)、Pipek-Mezey定域化分子轨道和FBO分析研究了这些产物分子中的成键性质。结果表明,所有分子的基态自旋多重度均为三重态。对于XCeF3,FXCeF2和F2XCeF,氮化物的热力学稳定性最高,其次是砷化物,磷化物的热力学稳定性最低;CeXF3的情况则正好相反。AIM分析表明,大多数Ce-X、X-F和Ce-F键主要呈现闭壳层相互作用特征,且具有部分共价作用特征。由于F2XCeF分子中存在agostic作用,Ce-F1(或F2)键表现出闭壳层相互作用的特征;且RCP与BCP相近,表明X-Ce-F1(或F2)三元环的稳定性较弱。

The structures,energies and spectra of the possible products(CeXF3,XCeF3,FXCeF2 and F2XCeF)of Ce reacting with XF3(X=N,P and As)were studied by ab initio methods.The bonding properties of these molecules were studied by atom-in molecule(AIM),natural population analysis(NPA),Fuzzy bond order(FBO)and Pipek-Mezey localized orbital methods.The results show that all molecules are triplet.For XCeF3,FXCeF2 and F2XCeF,the thermodynamic stability of nitride is the highest,followed by arsenide,and that of phosphide is the lowest.However,the case for CeXF3 is the opposite.The AIM results indicate that most of Ce-X,X-F and Ce-F bonds show mainly close-shell interaction character and have partial covalent character.Due to the agostic interaction in F2XCeF,the Ce-F1(or F2)bond shows close-shell interaction character,and the BCP is closed to RCP,which indicates that the stability of the X-Ce-F1(or F2)ring is weak.