【摘要】 具有双桥氯基的Ti、Zr、Hf的双核簇合物的电子结构是通过量子化学中DV-Xa方法计算得到的,计算结果表明:锆和铪的双核簇合物有M-M键存在,为抗磁性化合物;而钛的双核络合物不存在M-M键,并且在经过一次二级Jahn-Teller效应后,HOMO与LUMO能级差还是那么小,电子云弥散到LUMO,LUMO和HOMO好象是简并轨道,电子基本上是单占据的,所以是顺磁性化合物,这些结论与磁共振实验结果是一致的。更多还原

【Abstract】 Electronic structures of dinuclear complexes of Ti,Zr and Hf with two bridging cholorides are studied by molecular orbital calculations on model systems emeploying the DV-Xα method. The results show that dinuclear complexes of Zr and Hf, Which are diamagnetic,contain M-M bond, While dinuclear complex of Ti does not contain M-M bond. After a the second-order Jahn-Teller effect of the dinuclear complex of Ti the energy gap between HOMO and LUMO is so small that tlectron can easily diffuse to LUMO,LUMO and HOMO seem to become the degenerate orbital. Producing paramagntic character of the complex,Those show good agreement with H-NMR spectroscopy.更多还原