Studies of oxalate-bridged MM quadruple bonds and their radical cations (M = Mo or W): on the matter of linkage isomers
作者:Malcolm H. Chisholm、Jason S. D'Acchioli、Christopher M. Hadad、Nathan J. Patmore
DOI:10.1039/b501938a
日期:——
Electronic structure calculations employing density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been carried out on the model complexes [(HCO2)3M2]2(mu-O2CCO2)}0/+(M=Mo or W) in D2h symmetry, where the oxalate bridge forms either five- or six-membered rings with the M(2) centres; the complexes are hereafter referred to as mu(5,5)0/+ and mu(6,6)0/+, respectively
已对模型复合物[((HCO2)3M2] 2(mu-O2CCO2)} 0 / +(M = Mo或W)在D2h对称性中,草酸盐桥与M(2)中心形成五元或六元环;该复合物在下文中分别称为mu(5,5)0 / +和mu(6,6)0 / +。计算结果表明,中性复合物应以mu(5,5)链接异构体形式存在,而自由基阳离子在大约ca时有利于mu(6,6)异构体。4-6 kJ mol-1。对于mu(5,5)异构体,对于M = Mo和W,草酸CC键的旋转势垒分别为15.9和27.2 kJ mol-1。对于阳离子mu(5,5)+异构体,势垒较高,M = Mo和W分别为36.8和50.6 kJ mol-1。将mu(5,5)0 / +和mu(6,6)0 / +的拉曼光谱和可见近红外光谱与[(tBuCO2)3M2] 2(mu-O2CCO2 )} 0 / +复合物,以下称为M4OXA0 / +(M = Mo或W)。实验数据与对mu(5