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运用密度泛函理论研究了(1,3,5-C_3P_3H_3)M和(1,3,5-C_3P_3H_3)_2M(M=Ti,V,Cr)的结构、键合能以及芳香性.结果表明:低自旋的(1,3,5-C_3P_3H_3)M和(1,3,5-C_3P_3H_3)_2M基态结构分别具有C_(3v)和D_(3h)对称性.金属与配体间为共价作用,二者之间存在σ、π和δ三种成键方式.V的三明治配合物的解离方式与Ti和Cr的三明治配合物不同,前者为分步解离,后两者则为一步解离.其中(1,3,5-C_3P_3H_3)_2Cr(D(3h))的第一解离能最大,配合物最稳定.这些三明治和半三明治配合物都具有中心芳香性、内芳香性和外芳香性,且中心芳香性均大于自由配体(1,3,5-C_3P_3H_3)的中心芳香性.芳香性主要贡献来源于π键和金属原子的孤对电子.内芳香性按照Ti、V、Cr的顺序依次增大,且内芳香性明显要大于外芳香性.高自旋的半三明治(1,3,5-C_3P_3H_3)Ti(C_3,~5A_1)与单重态(1,3,5-C_3P_3H_3)Ti(C_(3v),~1A_1)相比,配体的变形性增大,稳定性增加,且C平面中心芳香性和内芳香性均增大,但P平面的中心芳香性却降低.
The structures, bonding energies and aromaticity of (1,3,5-C_3P_3H_3) M and (1,3,5-C_3P_3H_3) _2M (M = Ti, V, Cr) were studied by using density functional theory The low-spin (1,3,5-C_3P_3H_3) M and (1,3,5-C_3P_3H_3) _2M ground state structures have C_ (3v) and D_ (3h) symmetry, respectively. , There are three kinds of bonding modes of σ, π and δ.The sandwich structure of V is dissociated from sandwich structure of Ti and Cr, the former is step-by-step dissociation and the latter two are one-step solution (1,3,5-C_3P_3H_3) _2Cr (D (3h)) exhibited the highest first dissociation energies and the most stable complexes.These sandwich and semi-sandwich complexes all have central aromaticity, internal aromaticity and external Aromatic, and the central aromaticity is greater than the central aromaticity of the free ligand (1,3,5-C_3P_3H_3) .The main contribution of aromaticity comes from the π bond and the lone pair electrons of the metal atom.The internal aromaticity is in accordance with Ti, V, Cr in the order of increasing, and the internal aroma is obviously greater than the external aroma.The high spin of the semi-sandwich (1,3,5-C_3P_3H_3) Ti (C_3, ~ 5A_1) and singlet (1,3,5-C_3P_3H_3 ) Ti (C_ (3v), ~ 1A_1), the deformability of the ligand is increased, the stability is increased, Aromatic C-plane and the central aromatic were increased, but the center plane P but aromatic reduced.