[Co(N-(3-Aminopropyl)-1,3-propanediamine)(2-(Aminomethyl)pyridine) Cl][ZnCl_4]的一对差向异构体的合成及晶体结构

The Crystal Structures of a Pair of [Co(N-(3-Aminopropyl)-1, 3-propanediamine)(2-(Aminomethyl)pyridine)Cl][ZnCl4] Epimers

用过氧化物法合成了 [Co(3,3-tri)(amp)Cl][ZnCl4]的两个经式异构体，晶体结构解析表明两者互为差向异构体。其中反式异构体 (仲氢相对于 Cl)晶体属单斜晶系，空间群 C2/c， a=2.7663(7)nm， b=0.9505(1)nm， c=1.8288(4)nm，β =105.57(2)°， V=4.632(1)nm3， Dc=1.706g· cm-3， Z=8， F000=2432.00，μ (MoKα )=23.51cm-1， R=0.033， Rw=0.041；顺式异构体 (仲氢相对于 Cl)晶体属三斜晶系，空间群， a=1.0790(2)nm， b=1.1749(1)nm， c=0.8920(1)nm，α =90.73(1)°，β =109.573(9)°，γ =80.60(1)°， V=1.0500(2)nm3， Dc=1.71g· cm-3， Z=2， F000=548.00，μ (MoKα )=25.73cm-1， R=0.022， Rw=0.030。两异构体中 Co3＋为六配位，其差异仅表现在 3,3-tri仲胺上氢的取向不同。

：Two geometric meridional isomers in a new [Co(bamp)(cmen)Cl]2＋ (bamp=2,6-(Aminometh- yl)pyridine;cmen=1,2-diaminopropane) system were synthesised and isolated. The structures of the isomers were assigned by using 2D NMR techniques such as gCOSY. Comparing to the eluates from the chromatographic column, the first band contains the m2, the second band contains the m1. Also the crystal structure of the m2[ZnCl4] also were determized by X-ray diffraction determination. The stability of the isomers was studied by using ab initio method of quantum chemistry at RHF/LANL2DZ level. The calculation results shows that the difference of the ground energies of the two geometric isomers is 10.6kJ· mol-1 in water (E0m1 >E0m2), and the distribution of the two isomers is m1∶ m2=2∶ 3. A comparison the structural parameters of the [Co(bamp)(cmen)Cl]2＋ isomer shows that the errors between the calculated results and those from the X-ray diffraction determination are less than＋ 3％ generally.