Hydrolytic property and solution stability of NAMI derivative containing nicotinamide

Objective: To study the influence of ligand structure on hydrolysis and solution stability of NAMI derivatives.Method: NAMI type compound 1,trans-[RuCl4(DMSO)(nica)]Na·2DMSO(nica,nicotinamide) were prepared.Their hydrolytic mechanism,kinetics and stability were investigated by UV-Vis spectrophotometer.Result: Similar to NAMI,compound 1 undergoes two well-separated steps chloro-hydrolysis(I chloro-hydrolysis and II chloro-hydrolysis)(step reaction) in pH 7.4 buffer solution;while dimethyl sulfoxide(DMSO) hydrolyze in pH 5.00 acetic buffer solution.The kobs and t1/2 for each hydrolytic reaction were determined.Conclusion: The stability of compound 1 in acidic solution is much more stable than that of in neutral solution.Nicotinamide in place of imidazole can decrease chloro hydrolytic rate of NAMI derivatives obviously,while the influence on the DMSO hydrolytic process is not so remarkable.