过渡金属离子与Schiff碱配合物的研究——Ⅰ.双-[N-(4-甲基苯基)水杨醛亚胺]钴(Ⅱ)的晶体结构与电子结构

CRYSTAL AND ELECTRONIC STRUCTURES OF SCHIFF BASE COMPLEXES WITH TRANSITION METAL IONS——Ⅰ. BIS-(N-(4-METHYL-PHENYL)-SALICYLALDIMINATO) Co(Ⅱ)

过渡金属离子与Schiff碱配合物的合成与性质研究始自50年代,并已有不少论文发表。70年代发现Co(Ⅱ)与Schiff碱的配合物具有抗癌和抗肿瘤活性之后,这一领域的研究工作更加活跃,但对其结构和性质关系的研究多数尚通过谱学方法进行,对标题化合物也只有晶胞参数的报导。为了探讨该类化合物的分子结构与生理活性的关系,本文首先报导标题化合物的晶体与分子结构以及其电子结构的量子化学近似计算结果。

The molecular structure for the title complex has determined by single crystal X-ray analysis, using CAD4 diffractometer with Mo -Ka radiation. 3691 unique reflections were collected. The crystal data found were: monoclinic, space group C2/c, α= 21.755(4), b = 8.714(3),c=11.921(9)A, β= 96.42(6),V=2245.7A,Z = 4, M = 479.40, DC = 1.42g·cm-3. Open shell SCF calculation for the complex has been undertaken with M-160 computer and CNDO / 2 quantum chemistry program. The perspective drawing of the molecular structure is shown in Fig.1. General features of the structure displayed in Fig.l can be summarized as follows: two ligands attach to the central atom Co through their donor atoms N(1), O(1), N(1), and O(1) to form two six-membeted chelate rings, and Co atom is tetrahedrally coordinated by the four atoms mentioned above. The Co-N(1) bond distance is 1.978, Co-O(l), 1.892. Quantum chemistry calculation indicated that the 3d orbits of the central atom Co are involed in bonding formation, the bond orders, two center energies and net charge distributions are presented.