{[(C_6H_5)_3P]_2Cu}_2B_(12)H_(12)配合物晶体和分子结构

CRYSTAL AND MOLECULAR STRUCTURE OF {[(C_6H_5)_3P]_2Cu}_2B_(12)H_(12)

{[(C_6H_5)_3P]_2Cu}_2B_(12)H_(12)配合物晶体属三斜晶系,空间群 PI,晶胞参数为 a=12.134(3),b=15.521(3),c=11.236(3)(?);α=94.41(2)°,β=115.41(2)°,γ=103.47(2)°;Z=1.结构通过重原子 Patterson 及 Fourier 法解出,经块对角矩阵最小二乘法修正,对3699个独立衍射点的计算,最终偏离因子 R 为0.084.结构测定表明,硼笼阴离子 B_(12)H_(12)^(2-)位于晶体对称中心上,它通过两个螯合环■分别与以对称中心相联系的两个Cu(Ⅰ)原子配位,每个Cu(Ⅰ)原子进一步得到两个三苯基膦配位,形成近似四面体的配位结构.硼笼 B_(12)H_(12)^(2-)中的 B—B 平均键长为1.78■,B—H 为1.16■,Cu—P 和 Cu—B 的平均距离分别为2.270(4)和2.39(2)■.在螯合环■■的两个三中心键 Cu—H—B 中,Cu—H 的距离为1.82和1.88■,螯合环的五个原子几乎完全共面.

The crystal and molecular structure of{[(G_6H_5)_3P]_2Cu}_2B_(12)H_(12) has been determinedfrom three dimensional single-crystal X-ray data.The compound crystallizes in thetriclinic space group P(?),with α=12.134(3),b=15.521(3),c=11.236(3)(?);α=94.41(2)°,β=115.41(2)°,γ=103.47(2)° and Z=1.The structure was solved by the Patterson-heavy-atom and Fourier methods,and refined by block-diagonal least-squares techniquesto a final R of 0.084 for 3699 independent reflections.The B_(12)H_(12)^(2-) cage is situated at thecentre of symmetry and two bis(triphenylphosphine)copper(Ⅰ)are centrosymmetricabout the B_(12)H_(12)^(2-) cage.The B_(12)H_(12)^(2-) cage ligand binds to two centrosymmetric copperacorns by means of Gu—H—B—B—H chelate rings.Each copper atom is further bondedto two triphenylphosphine ligands and the coordination of the copper atom is nearlytetrahedral.The average distance of B—B within the B_(12)H_(12)^(2-) cage is 1.78(?) and theaverage value of B—H is 1.16(?).The average distances of Cu—P and Cu—B are 2.270(4)and 2.39(2)(?) respectively,which are in consistent with those published for the similarcomplexes.The distances of fwo Cu—H in the chelate rings Cu—H—B—B—H are 1.82and 1.88(?) respectively,and the five atoms of the chelated ring Cu—H—B—B—H arealmost coplaner.