Regulation of the Structure of di-nuclear complexes and chromotropic behaviors of the complexes

点击翻译按钮获取中文摘要

We have newly synthesized various kinds of mono- and di-nuclear mixed ligand complexes with nickel (I 1) and copper (II) ions and also have reinvestigated the well-known mononuclear complexes studied by us for determining their crystal structures. For the mononuclear complexes, their general formulas are : M (dike) (diam) X, M (dike) (triam) X, M (dike) (tetam) X where M=Ni (i 1) or Cu (i 1), dike=beta-diketonate, diam=ethylenediamine derivatives, triam=diethylenetriamine, tetam=triethylenetetraamine which are all N-alkylated, and X=B (Ph)_4^-, CIO_4^-, NO_3^-, halide or pseudohalide anions. For the di-nuclear complexes, they are shown M_2 (teke) (polyam)_2X_2 as the general formula i n which teke means the branched tetraketonate ligand worked as the bridging group such as 1, 1, 2, 2-tetraacetylethanate ligandand polyam=N-alkylated diam, triam or tetam used before. Another types of di-nuclear complexes are M_2 (CO_3) (dike)_2 (diam)_2, M_2 (C_2O_4) (dike)_2 (diam)_2, or M_2 (X)_2 (dike)_2 (diam)_2, in which (CO_3), (C_2O_4)or(X)_2 ligand act as the bridging ligands.The important factor to form stable mixed ligand complexes is the suitable combination of the ligands, i. e., in this case we use the bulky polyamine and the less-sterically hindered diketonate or tetraketonate. The stereochemical regulation are resulted from the steric effect of the bulky polyamine, electronic effect of polyketonate and the coordinating ability of the anions used. In addition to these results, fortunately, these mixed ligand complexes are very soluble in various organic solvents and show the characteristic chromotropismes such as solvatochromism and thermochromism in solution. For crystals of di-nuclear complexes, we could observe the weak antiferromagnetic interactions which depends upon the nature of the bridging ligands used.