摘要
This paper describes the catalytic performance of two manganese（III） complexes with mono-Schiff base ligands as artificial hydrolases towards the hydrolysis of p-nitrophenyl picolinate （PNPP）. Observations reveal that the one complex （ MnL22C1 ） containing morpholine pendants exhibits 1.2-1.7 fold kinetic advantage over the other one （MnL12C1） containing benzoaza-15-crown-5 group. Especially, optimum molecule structures using a Gaussian 03 software confirm that MnL2CI indeed possesses a relatively open linked site for the approaching of PNPP, result- ing in higher efficiency due to a convenient association between substrate （PNPP） and MnL2C1. In addition, the steric hindrance of two pendants, i.e., benzoaza-15-crown-5 and morpholine, may be a main influencing factor for tuning catalytic activities of the synthesized Mn（III） catalysts. Both Mn（III） catalysts used here were found to have fine tolerance to the operated temperature and pH. Related kinetic and thermodynamic analyses were also given to demonstrate their structure-activity relationships （SAR） of both catalysts used.
This paper describes the catalytic performance of two manganese（III） complexes with mono-Schiff base ligands as artificial hydrolases towards the hydrolysis of p-nitrophenyl picolinate （PNPP）. Observations reveal that the one complex （ MnL22C1 ） containing morpholine pendants exhibits 1.2-1.7 fold kinetic advantage over the other one （MnL12C1） containing benzoaza-15-crown-5 group. Especially, optimum molecule structures using a Gaussian 03 software confirm that MnL2CI indeed possesses a relatively open linked site for the approaching of PNPP, result- ing in higher efficiency due to a convenient association between substrate （PNPP） and MnL2C1. In addition, the steric hindrance of two pendants, i.e., benzoaza-15-crown-5 and morpholine, may be a main influencing factor for tuning catalytic activities of the synthesized Mn（III） catalysts. Both Mn（III） catalysts used here were found to have fine tolerance to the operated temperature and pH. Related kinetic and thermodynamic analyses were also given to demonstrate their structure-activity relationships （SAR） of both catalysts used.
