三核锇羰基化合物的理论研究

Theoretical Study on Trinuclear Osmium Carbonyls

研究对第3长周期过渡金属配合物最优的理论计算方法,预测有可能被实验合成的新三核锇羰基化合物的结构.采用3种密度泛函方法和2种有效核势基组对中性三核锇羰基化合物Os3(CO)n(n=12,11,10,9)进行理论计算,优化出18个稳定异构体.通过Os3(CO)12理论计算与实验数据的比较,说明MPW1PW91密度泛函方法与有效核势基组相结合,在预测第3长周期过渡金属羰基化合物分子构型和振动频率方面具有很好的可靠性.用该计算方法得到了不饱和三核锇羰基化合物Os3(CO)n(n=11,10,9)的优化结构,并与相应的铁羰基化合物进行了比较.

In order to find the best method of theoretical calculation for the transition metal compounds of the sixth period and predict the structure of the new compounds that can be synthesized experimentally, a series of neutral trinuclear osmium carbonyls Os3 （CO）n （ n = 12, 11, 10, 9） have been studied by three selected density functional theory （DFT） methods with two effective core potential （ECP） basis sets. Eighteen stable isomers were found. Comparison of the theoretical and experimental structural parameters as well as v （CO） frequencies for Os3 （CO）12 suggest that the DFT MPW1PW91 method with a suitable ECP basis set including relativistic effects represent a reliable method .for predicting structures and vibrational frequencies of third row transition metal carbonyl derivatives. Using this method, structures of unsaturated trinuclear osmium carbonyl derivatives Os3 （CO）n （n = 11, 10, 9） have been investigated for comparison with their iron carbonyl analogues.