(BCO)_5M和[(BCO)_5]_2M(M=Li^+,Na^+,K^+,Be^(2+),Mg^(2+),Ca^(2+))的结构与性质

Structures and Properties of (BCO)_5M and [(BCO)_5]_2M(M=Li^+,Na^+,K^+,Be^(2+),Mg^(2+),Ca^(2+))

运用高精度密度泛函B3LYP/6-311+G*方法,对(BCO)5M和[(BCO)5]2M(M=L i+,Na+,K+,Be2+,Mg2+,Ca2+)16种配合物的经典几何构型(正五角单锥(C5v),交错式(D5d)和重叠式(D5h))进行了理论计算.优化构型稳定,对称性高.同系配合物中,RB-C值在同一主族中从上到下依次减小,而同一周期中则从左到右依次增大,RB-M值的变化规律与之相反.所有配合物中,B均带负电荷,且都比基本配体1([(BCO)5]-)中的多.金属M所带正电荷(同一系列配合物中)随着主量子数的增大而增大,C则相反;同时随着质量数的增大,C和M所带正电荷均呈增大趋势.这些变化均与金属离子所带电荷和原子半径有关.分子轨道的分析阐述了配合物的成键本质.同时还从HOMO轨道能量预测出这些配合物的第一电离势,具有实际参考意义.

We have adopted B3LYP/6 -311 ＋ G^＊ method to optimize the typical structures of sixteen boron carbonyl metallocenes, （BCO）5M and [BCO）5]2M（M=Li^＋,Na^＋,K^＋,Be^2＋,Mg^2＋,Ca^＋）. Most of the structures of these complexes are steady with expected. The values of RB-C of these complexes that are in the same series gradually decrease from the top down, but gradually increase from left to right in the elements periodic table. The Variation tendency of RB-M reverses to that of RB-C- The charges of B in all the complexes are not only negative, but also more than that of 1 （ [ （BCO） 5 ] - ）- The positive charges of M are increased with the augmentation of main quantum numbers in the same series, while the condition of C atoms is on the contrary. Meanwhile the positive charges of M and C both rise as mass numbers rising. All the variations are associated with the charges and atomic radiuses of metals. We also predict the first-electron-detachment energies of the corresponding complexes from the energy of HOMO orbitals, which have great importance to the experiments.