STUDIES OF STABILITY OF CO-N BOND ON THE VB12 MODEL MOLECULE

Vitamin B-12 model molecule, dicyano hexamethyl-N-(3-imidazoly) propyl amido cobyrinates perchlorate 4b-4f were synthesized and treated with acidic buffers in methanol, and the ring was opened to give compounds 5b-5f. UV-Vis spectra were determined in buffers with different pH val ues, and equilibrium constants of Co-N bonds were calculated, The stre ngth of coordination bonds between N atom in the side chain of cobyrin ates and Co atom was in the order of 4d>4f>4c>4e>4b.