Novel Michael Addition Products of Bis(amino acidato)metal(II) Complexes: Synthesis, Characterization, Dye Degradation, and Oxidation Properties

Abstract

Michael addition reactions of bis(amino acidato)metal(II) complexes (metal = copper, nickel, zinc; amino acid = glycine, dl-alanine, l-alanine) with acrylonitrile have been carried out under various experimental conditions in the absence of a base, resulting in mono- and disubstituted products in high yield, including partially hydrolyzed products. A reaction mechanism for the Michael addition on the nitrogen atom of the coordinated amino acid moiety, replacing the amino hydrogen atom(s), is proposed. All of the products have been characterized by Fourier transform infrared spectroscopy, electron paramagnetic resonance spectra, and elemental and electrochemical analyses. The single-crystal structures of bis( N-cyanoethylglycinato)copper(II) monohydrate ( 1a), diaquabis( N-cyanoethylglycinato)nickel(II), aquabis( N, N-dicyanoethylglycinato)copper(II) ( 2a), and bis[( N-propionamido- N-cyanoethyl)glycinato]copper(II) dihydrate ( 4a) have been confirmed by X-ray diffraction techniques. The products 1a, 2a, 4a, and bis( N-propionamidoglycinato)copper(II) monohydrate ( 3a) have been used as catalysts for the degradation of a phenol red dye and mild oxidation of various organic substrates in the presence of hydrogen peroxide. The monosubstituted complexes have been found to catalyze the reactions to a greater extent than the disubstituted complexes.

Oxidant-Controlled C-sp2/sp3–H Cross-Dehydrogenative Coupling of N-Heterocycles with Benzylamines

“…During the course of oxidant optimization studies, we surprisingly obtained benzoic acid 3aa from benzylamine 3a under TBHP/IL conditions (entry 3 of Table ). After conducting a literature search, it was observed that conversion of benzyl amine 3a to benzoic acid 3aa requires a metal catalyst, − dual oxidant, or bio-oxidation . Therefore, we explored the scope of this transformation for various substituted benzylamines.…”

Construction of a Hierarchical Structure of Bimetallic Oxide Derived from Metal–Organic Frameworks

“…Bimetallic oxide, as a metal oxide material composed of two different metals, has aroused extensive attention concerning many domains including photocatalysis, , dye degradation, , gas sensing, , and electrochemical sensing, − ascribed to the numerous accessible metal active sites and inherent physical–chemical properties. In addition, because different types of metals usually endow target materials with specific functionality, most of the bimetallic oxides lead to enhanced performance because of the synergistic effect between two metals. ,, The common strategies to prepare bimetallic oxides include the sol–gel method, , coprecipitation, , and solvothermal and electrochemical deposition .…”

Synthesis and structure of Zn(II) and Cu(II) complexes derived from 2-(aminomethyl)benzimidazole and glycine

“…Indeed, the broad signal at 672 cm −1 suggests the presence of H 2 O→Cu and H 2 N→Cu coordinated bonds in 3[35][36][37][38]. IR spectra of 2 and 3 have the characteristic of asymmetric (1603 cm −1 for 2 and 1602 cm −1 for 3) and symmetric (1402 cm −1 for 2 and 1401 cm −1 for 3) COO stretching frequencies.Separations between ν a (COO) and ν s (COO) vibrations (δ = 200 cm −1 for 2 and 191 cm −1 for 3) show that carboxylates are unidentate bonded to metal ions in 2 and 3[15,[38][39][40]. Broad signal at 543 cm −1 (for 3) and 528 cm −1 (for 2), previously assigned to ρ r (H 2 O), could include the ν(M-O) vibrations…”