Bis‐β‐(diketonates) Zn(II) complexes substituted with thiophene: Electropolymerization, homogeneous and heterogeneous catalysis for ring opening polymerization of lactide

Abstract

Two Bis‐β‐diketonate zinc (II) complexes were synthesized using 1‐(thiophen‐2‐yl)butane‐1,3‐dione and 1‐(thiophen‐2‐yl)‐3‐(thiophen‐3‐yl)propane‐1,3‐dione as ligands. By electropolymerization of their thiophenyl groups, the metallopolymers deposited on FTO electrodes were obtained. The main objective was to study the reactivity of these compounds as ROP catalysts for PLA synthesis, using directly the zinc complexes (homogeneous catalysis) and also the modified electrodes with metallopolymers (heterogeneous catalysis). The homogeneous catalysis studies allowed the optimization of the polymerization conditions, such as reaction time, catalyst concentration, and the use of benzyl alcohol as cocatalyst, as well as their influence on the conversion rate, average molecular weight and polydispersity of PLA, using rac‐LA and L‐LA as monomers. Also, the effect on tacticity and thermal properties were discussed. Finally, the ROP studies using immersed modified electrodes in the polymerization medium were carried out under optimized experimental conditions. These tests were positive for one of the studied compounds, reaching conversions of up to 67%. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 557–567

Spectroscopy, molecular structure, and electropolymerization of Ni(ii) and Cu(ii) complexes containing a thiophene-appending fluorinated Schiff base ligand

“…32,33 In addition, the electrochemical polymerization of Schiff base complexes containing 2-thienyl scaffolds has been leveraged in the fabrication of materials with applications in the fields of conducting metallopolymers, [34][35][36] non-linear optics, 37 transistors, 38 spincrossover, 39 and catalysis. 40,41 In recent years, our research team has been engaged in the preparation of metallopolymers using Schiff base complexes, specifically since they offer the ability to integrate catalytic properties 10,42 to be used as glucose sensor 43 or to modulate the non-linear optical responses in the preparation of mainand side-chain metal-containing polymers. [44][45][46] In this context, we have previously disclosed the preparation of a series of cobalt(II), nickel(II), and copper(II) complexes of a fluorinated Schiff base ligand formally resulting from the condensation of 2-thenoyltrifluoroacetone (TTA) with 1,2-diaminoethane; cyclic voltammograms of these complexes displayed oxidation waves indeed, but none of them formed polymer films upon repeated cycling.…”

“…4,5 Furthermore, the interest in metal-containing polymers (MCP) lies in their promising applicability in electrical, 6 optical, 7,8 biological, 9 and catalytic applications. 10 Conducting polymers can be easily obtained by the electrochemical oxidation of aromatic monomers on an electrode † This paper is dedicated to Professor Jean-Yves Saillard, our esteemed colleague and friend, not only on the occasion of his 75th anniversary but also in recognition of his profound engagement in our fruitful long-term collaboration and for his invaluable contribution to inorganic and cluster chemistry. ‡ Electronic supplementary information (ESI) available: Fig.…”

“…4,5 Furthermore, the interest in metal-containing polymers (MCP) lies in their promising applicability in electrical, 6 optical, 7,8 biological, 9 and catalytic applications. 10…”

Copolyesters of ε-caprolactone and l-lactide catalyzed by a tetrabutylammonium phthalimide-N-oxyl organocatalyst

“… 12 Aluminum complexes modified by varying the ligand were utilized to produce well-defined polymers with high catalytic efficiency and selectivity to ROP of lactones. 13,14 Zinc alkoxides were friendly substitution of Tin analogue due to their bioresorbable characteristic 15 and proved to be high effective for ROP of l -LA at room temperature with good control of polymer structure. 16 …”