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The ring opening copolymerization (ROCOP) of epoxides and cyclic anhydrides is one of the most important ways to synthesize polyesters both in industrial and academic fields. Herein, the zeolitic imidazolate framework‐67 (ZIF‐67) was used as a heterogeneous catalyst for the ROCOP of epoxides and cyclic anhydrides without co‐catalyst and initiator. Notably, the obtained polyesters with alternate structures were proved by the 1H NMR spectrum and FTIR spectrum, which indicate the ROCOP is alternatively copolymerized. Kinetic study of the ROCOP of cyclohexene oxide (CHO) and phthalic anhydride (PA) shows that the polymerization reaction is first‐order kinetics. The apparent activation energy (Ea) of the ROCOP of CHO and PA catalyzed by ZIF‐67 was found to be about 104.4 KJ/mol. A possible mechanism of ROCOP of CHO and PA is that the metal Co coordinates with the oxygen atom on the monomer to weaken the C‐O bond thereby opening the ring structure and initiating the copolymerization reaction. In this study, a new system for the copolymerization of epoxide and anhydride catalyzed by heterogeneous catalysts was discovered, which has important guiding significance. [ABSTRACT FROM AUTHOR]

The conversion of CO2 into value-added chemicals has become an imminent research topic and the cycloaddition of CO2 with a C1 resource to produce cyclic carbonates is a promising pathway for CO2 utilization. Herein, a series of POSS-based polyionic liquids (PILs) were synthesized by the copolymerization of octavinyl polyhedral oligomeric silsesquioxane (POSS) with an imidazolium ion linker. The prepared PILs have the characteristics of hydrogen bond donors, halogen atom sites, stable pore structures, and thermal stability, and are used as heterogeneous catalysts for the cycloaddition of epoxides with carbon dioxide. The effect of linkers on the cycloaddition is investigated by tuning the ratio of POSS units to imidazolium ions. Under the optimized conditions, the conversion of epichlorohydrin can reach 99.18% at atmospheric pressure with neither co-catalysts nor solvents. It is concluded that the reaction of the cycloaddition of epoxides with carbon dioxide follows pseudo-first-order kinetics. Moreover, the presence of the catalysis of PILs leads to a significant decrease in the activation energy barrier for cycloaddition. The catalyst can be facilely recovered due to its high stability, and only a slight decrease in conversion was observed after five successive runs. In addition, the mechanism of PILs catalyzing the cycloaddition reaction of epoxides with CO2 is proposed. This work not only provides a sustainable and green process for CO2 cycloaddition, but also highlights the potential of using PILs for CO2 utilization. [ABSTRACT FROM AUTHOR]

Photo-induced controlled radical polymerization (CRP) mediated by heterogeneous catalysts provides excellent spatiotemporal control and has been widely studied in view of green chemistry and potential biomedical applications. In this paper, an ionic heterogeneous catalyst (TD-I) was synthesised in a facile manner under mild conditions for inducing the reversible complexation-mediated polymerization (RCMP) of poly (polyethylene glycol monomethyl ether methacrylate) (PPEGMA) in an aqueous solution under white LED light irradiation. The obtained PPEGMA has a controllable molecular weight and a narrow molecular weight distribution. The spatio-temporal control of the catalytic system and the high chain end fidelity of the polymer have been successfully verified by on-off light experiments and chain expansion experiments. The activity and efficiency of TD-I remained essentially unchanged after being used for three cycles. Such a heterogeneous photocatalyst which can be easily separated and efficiently reused is promising for industrial applications. [ABSTRACT FROM AUTHOR]

The generation of cyclic carbonates by the cycloaddition of CO2 with epoxides is attractive in the industry, by which CO2 is efficiently used as C1 source. Herein, a series of catalysts were developed to efficient mediate the cycloaddition of CO2 with epoxides to generate carbonates. The catalysts were easily synthesized via the amine‐formaldehyde condensation of ethidium bromide with a variety of linkers. The newly prepared heterogeneous catalysts have high thermal stability and degradation temperatures. The surface of the catalysts is smooth and spherical in shape. The effect of temperature, pressure, reaction time and catalyst dosage on the cycloaddition of CO2 with epoxide were investigated. The results show that the catalyst with 1,3,5‐tris(4‐formylphenyl)benzene as the linker can achieve 97.4 % conversion efficiency at the conditions of 100 °C, reaction time of 12 h, and the reaction pressure of 1.2 MPa in a solvent‐free environment. Notably, the polymers serve as homogeneous catalysts during the reaction (reaction temperature above Tg) and can be separated and recovered easily as homogeneous catalysts at room temperature. In addition, the catalyst is not only suitable for a wide range of epoxide substrates, but also can be recycled many times. Furthermore, DFT calculations show that the coordination between the electrophilic center of the catalyst and the epoxide reduces the energy barrier, and the reaction mechanism is proposed based on the reaction kinetic studies and DFT calculations. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are a class of promising photocatalysts for conversing light energy into chemical energy. Based on the tunable building blocks, COFs can be well‐designed as photocatalyst for mediating reversible addition‐fragmentation chain‐transfer (RAFT) polymerization. Herein, 1,3,6,8‐tetrakis(4‐formylphenyl)pyrene (TFPPy) and 2,2″‐bipyridine‐5,5″‐diamine (Bpy) are chosen to construct imine‐based TFPPy‐Bpy‐COFs for catalyzing RAFT polymerization of methacrylates under white light irradiation. The well‐defined polymers with precise molecular weight and narrow molecular weight distribution are obtained. The switch on/off light experiments suggest excellent temporal control toward RAFT polymerization system and the chain‐extension reaction indicates high chain‐end fidelity of macro‐initiators. Mechanism study clarifies that the electron transfer between excited state of TFPPy‐Bpy‐COFs and RAFT agent can form living radicals to mediate polymerization. This methodology provides a novel platform for reversible‐deactivation radical polymerization using COFs as heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Tailoring cobalt phosphide electrocatalysts with a tunable phase and morphology is of great importance for the advancement of hydrogen evolution reaction (HER). The synthesis of phase‐ and morphology‐modulated hollow cobalt phosphide nanoparticles coupled with N, P, S co‐doped carbon (Co‐P@NPS‐C) polyhedrons through a facile three‐step method is reported. Benefiting from the cooperation of structural features, heteroatoms doping, and catalytic components (CoxP, a mixture of CoP and Co2P), the hollow CoxP@NPS‐C polyhedrons exhibit superior HER performance and long‐term stability in 1.0 m KOH solution, with a low onset potential value (18 mV), an overpotential of 80 mV at 10 mA cm−2, and a small Tafel slope of 57.6 mV dec−1. In addition, the CoxP@NPS‐C electrodes exhibit good electrochemical properties and stability in 0.5 m H2SO4 solution. These results suggest a novel and promising coating approach with poly(cyclotriphosphazene‐co‐4,4′‐sulfonyldiphenol (PZS) to fabricate other heterogeneous catalysts for various applications. [ABSTRACT FROM AUTHOR]

High crystallinity of fully sp2 COF, TCPB-DMTA-COFs , was constructed and served as heterogeneous photocatalyst for inducing atom transfer radical polymerization with the assist of ppm-level of Copper as co-catalyst under LED light irradiation, producing polymers with narrow molecular weight dispersity and highly chain-end fidelity. [Display omitted] • Fully-π conjugated covalent organic framework, TCPB-DMTA-COF , was successfully designed and synthesized. • TCPB-DMTA-COF was served as photocatalyst to mediate photo-induced ATRP with the assist of ppm-level copper under LED irradiation, producing polymers with uniform molecular weight and narrow molecular weight dispersity. • The switch on/off experiments and chain extension reaction proved the high chain-end fidelity of the obtained polymers and temporal control of polymerization processes. • Comparing with TCPB-DMTA-CMP , TCPB-DMTA-COF with high crystallinity presented better catalytic properties during polymerization, providing that the crystallization of COF strongly improves its catalytic polymerization. • Mechanism study of polymerization processes by EPR experiments reveal the formation of radical. Photo-induced atom transfer radical polymerization (ATRP) becomes a significant method for preparing well-defined polymers with pre-designable molecular weight and narrow molecular weight dispersity (M w / M n). Herein, a fully-π covalent organic framework (COF) was constructed and served as heterogeneous photocatalyst for photo-induced ATRP under LED irradiation. TCPB-DMTA-COF , which was constructed by Knoevenagel polycondensation of 1,3,5-tris(4-cynomethylphenyl)benzene (TCPB) and 2, 5-Dimethoxy-terephthalaldehyde (DMTA) and exhibited remarkable performance in mediating photo-induced ATRP of methyl methacrylates with the assist of ppm-level concentration of CuII under LED irradiation, producing polymers with high chain-fidelity and low value of M w / M n (1.10–1.35). The switch "on/off" experiment exhibits excellent temporal and spatial control toward polymerization system. Compared with TCPB-DMTA-CMP, the high crystallinity and stability of TCPB-DMTA-COF endows high monomer conversion and good recyclability performance for photo-induced ATRP. These results suggest COF can be served as a promising artificial photocatalyst for photo-induced ATRP. [ABSTRACT FROM AUTHOR]

A binuclear molybdenum Schiff-base complex was prepared under mild conditions, fully characterized and applied as a heterogeneous catalyst for efficient synthesis of the epoxidation of alkenes. [Display omitted] • The catalyst has excellent catalytic efficiency in epoxidation reaction with various olefin, including linear and cyclic alkenes. • The catalyst could separation from the reaction mixture mainly basing on filtration and centrifugation. • The catalyst could be successfully recycle after the reaction. • The catalyst has both the advantages of homogeneous catalyst and heterogeneous catalyst. Dimolybdenum Schiff-base complex (DMSBC) which contain O ,N- bidentate ligand was synthesized and characterized. The complex can be used as a promising catalyst in the epoxidation of olefins with tert-butyl-hydroperoxide (TBHP) as oxidant. The catalytic activity of the DMSBC was optimized by adjusting various parameters. Epoxidation of olefins by DMSBC indicated that the catalyst exhibited superb catalytic activity with high conversions up to 99.6%, high selectivity up to 100%, and high turnover frequency (TOF) of 208 h−1. Kinetic analysis provided that epoxidation of cyclooctene by DMSBC possessed moderate activation energy (95.3 ± 2 kJ·mol−1). Furthermore, the calculated pre-exponential factor (A) proved that strong collisions probability take place in the reaction. Additionally, the recycle experiments demonstrated that DMSBC could be recovered and repeatedly applied. [ABSTRACT FROM AUTHOR]