[Co(bamp)(pi)Cl][ZnCl_4]·H_2O一经式异构体的晶体结构及经式异构体的理论计算研究(英文)

Crystal Structure and Computational Study on the Isomers of mer[Co(bamp)(pi)Cl][ZnCl_4]·H_2O

用X射线单晶衍射法测定了CobamppiClZnCl4体系的一经式异构体m2的晶体结构bamp=26二氨基甲基吡啶pi=12氨基乙基哌啶晶体属于三斜晶系空间群#2a=11.3234b=11.7473c=10.6173α=115.452°β=113.322°γ=77.953°V=1169.763Dc=1.661g·cm-3Z=2F000=596.00μMoKα=23.20cm-1R=0.032Rw=0.044。用量子化学从头计算方法在赝势基组RHF/LANL2DZ的水平上对该体系的两经式异构体在不同介质中的稳定性进行比较其能量差分别为11.3kJ·mol-1气相和27.3kJ·mol-1水介质。从而解释了在水介质条件下难于合成分离出另一经式异构体m1。

The crystal structure of the m2 isomer of [Co(bamp)(pi)Cl] has been determined (bamp=2,6 bis(2 aminomethyl)pyridine;pi=1 (2 aminomethyl)piperidine) by single crystal X ray diffraction analysis. Crystal data: triclinic, (# 2),a=11.323(4)? ,b=11.747(3)? ,c=10.617(3)? ,α =115.45(2)° ,β =113.32(2)° ,γ =77.95(3)° ,V=1169.7(6)? 3,Dc=1.661g· cm- 3,Z=2,F000=596.00,μ (MoKα )=23.20cm- 1,R=0.032,Rw=0.044. A comparison of the crystal structure of the m2 [Co(bamp)(pi)Cl] complex with an ab initio computational result (RHF/LANL2DZ optimised structure) suggests why the m1 isomer has not been isolated or even observed. The energies of the two isomers are calculated, the results show that the m1 isomer is 11.3kJ· mol- 1 less stable than the m2 isomer in the gas phase, and 27.3kJ· mol- 1 less stable when the effect of solvent (water) is included using the Onsager model within the solvent continuum reaction field method.