10.1016/j.ica.2011.06.024
The research presents the synthesis, characterization, and study of a new 2D copper(II)-Schiff base coordination polymer with magnetic and catalytic properties. The complex was prepared using the Schiff base ligand NN0-bis(salicylidene)-1,3-diaminopentane (H2L) and sodium dicyanamide (dca), resulting in a 2D hexagonal structure formed by helical chains connected through double 1,5-dca bridges. The complex exhibited strong antiferromagnetic coupling and was tested for its ability to catalyze the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ), showing catecholase-like activity. Various analyses were employed, including Fourier transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, cyclic voltammetry, electrospray ionization mass spectrometry (ESI-MS), X-ray crystallography, and magnetic susceptibility measurements, to characterize the complex and monitor the catalytic oxidation reaction. The study also involved kinetic studies to determine the catalytic activity and compared the complex's performance to that of natural catechol oxidase.
10.1021/ja00533a028
The research investigates the reaction mechanisms of oxygen transfer from the peroxy anion of N5-ethyl-4a-hydroperoxy-3-methyllumiflavin (4a-FlEtO2-) to various phenolate anions, aiming to understand the underlying processes and provide insights into biomimetic reactions of flavoenzyme dioxygenase. The study found that 4a-FlEtO2- can transfer both oxygen atoms to phenolate anions, leading to the formation of specific products and regeneration of reduced flavin. Key chemicals involved include 4a-FlEtO2-, phenolate anions such as 3,5-di-tert-butylcatechol (VIII), 10-methyl-9-phenanthrol (Ib), and 10-ethoxy-9-phenanthrol (Ia), and their respective products like 3,5-di-tert-butyl-o-quinone (IX), 10-hydroxy-10-methyl-9,10-dihydro-9-phenanthrone (IIIb), and 9,10-phenanthrenequinone (V). The research concludes that the oxygen-donating intermediate formed from 4a-FlEtO2- is likely a dioxetane or an oxygen molecule loosely associated with the flavin, and the reaction efficiency of 4a-FlEtO2- exceeds that of molecular oxygen by a significant margin, indicating a unique and efficient oxygen transfer mechanism.