中文摘要：

采用密度泛函理论（DFT）B3LYP/6—31G方法研究了二氯三苯基磷在分子势能超曲面上的4种稳定结构，计算了结构Ⅰ—Ⅳ的能量、红外及拉曼光谱、原子的化学位移和耦合常数，并作了频率分析，确认存在离子态的四配位磷化合物和三角双锥型的五配位磷化合物．结构Ⅰ，Ⅲ，Ⅳ是能量的最低点，没有虚频，结构Ⅱ有一个虚频，是一鞍点的过渡态，鞍点结构具有Cl—FL—Cl三重轴，3个苯环共平面，结构Ⅲ也有Cl-P—Cl三重轴，苯环呈扭曲螺旋状，能量最低，结构Ⅰ呈离子态、松散状结构，结构Ⅳ呈尖塔状，苯基取螺旋型，为四配位闸型结构，是一复杂的电荷转移体．

英文摘要：

The geometries of triphenyldichlorophosporane are optimized, and four stable conformations are found by using DFT B3LYP/6-31G^＊＊ method. The electronic structures, energies, infrared spectroscopy （IR）, Raman spectroscopy, nuclear magnetic resonance spectroscopy （NMR）, the chemical shift of all the atoms, and the coupled constants of the stable conformations Ⅰ to Ⅳ are calculated at DFT BSLYP/6-31G^＊＊ level. The triphenydichlorophosphorane exists in four-coordinated Ph3PCl2 and five-coordinated compound （trigonal bipyramidal） forms. The conformations Ⅰ, Ⅲ and Ⅳ are the minima, having no imaginary frequency. However, the conformation Ⅱ is a transition state with one imaginary frequency, which is a third-order saddle point, in which the three phenyl groups are coplanar. The conformation Ⅰ is a structure with loosely bound ion-pair between a pyramidal cation Ph3PCl^＋ and a Cl^- anion, and the three phenyl rings are twisted. Structure Ⅳ is pyramidal and has twisted phenyl rings.