CuⅡ and CuⅠ Complexes of 1,1'-(Pyridin-2-ylmethylene)-bis3-(pyridin-2-yl)imidazo1,5-apyridine:in situ Generation of the Ligand via Acetic Acid-controlled Metal-ligand Reactions

摘要

Reaction of 3-(pyridin-2-yl)-imidazo[1,5-a]pyridine(HPIP), Cu Cl2·2H2O and picolinaldehyde in the mixture of CH3 COOH and Et OH under solvothermal conditions gave complexes [LCuCl][Cu2Cl3](1) and [HLCu Cl]2[Cu Cl2]2[Cu Cl3]·2H2O(2)(L = 1,1?-(pyridin-2-ylmethylene)bis[3-(pyridin-2-yl)imidazo[1,5-a]pyridine]) simultaneously. The ligand L was generated via in situ metal-ligand reaction between HPIP and picolinaldehyde. When Cu Cl2·2H2O was replaced by Cu Cl, the 2:1:1(HPIP:picolinaldehyde:Cu Cl) reaction afforded complex [Cu3L2Cl2][Cu Cl2]·2H2O(3) and the analogous 2:1:3 reaction generated compound [Cu3L2][Cu Cl2]3(4). Complexes 1 and 2 are CuⅡ/CuI mixed-valence compounds. Complexes 1~4 display four various structures. It is found that the formation of the L ligand is controlled by CH3 COOH. This work reveals that the structures of complexes 1~4 could be rationally tuned via the inclusion of CH3 COOH in the reaction systems, the proper selection of different starting materials and the dexterous adjustment of the ratio of the starting materials.