scholarly journals A New Dinuclear Cobalt Complex for Copolymerization of CO2 and Propylene Oxide: High Activity and Selectivity

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4095
Author(s):  
Wen-Zhen Wang ◽  
Kai-Yue Zhang ◽  
Xin-Gang Jia ◽  
Li Wang ◽  
Lei-Lei Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Catalytic Reaction ◽  
Density Functional ◽  
Cobalt Complex ◽  
Catalyst System ◽  
High Catalytic Activity ◽  
Weight Yield ◽  
Carbon Dioxide Co2

Based on the ligand H4Salen-8tBu (salen-4), a new dinuclear cobalt complex (salen-4)[Co(III)TFA]2 (salen-4 = 3,5-di-tert-butylsalicylaldehyde-3,3′-diaminobiphenylamine; TFA = trifluoroacetic acid) has been firstly synthesized and characterized. It shows high catalytic activity for the copolymerization of propylene oxide (PO) and carbon dioxide (CO2), yielding regioregular poly(propylene carbonate) (PPC) with little generation of propylene carbonate (PC) by-product. It has been found that (salen-4)[Co(III)TFA]2 shows higher activity at milder conditions, generating a polymer with maximum Mn of 293 kg/mol and a narrow molecular weight distribution PDI of 1.35. The influences of reaction time, CO2 pressure, reaction temperature, nature of the cocatalyst, catalyst dosage and substrate concentration on the molecular weight, yield and selectivity of the polymer were explored in detail. The results showed that the (salen-4)[Co(III)TFA]2/[PPN]TFA catalyst system demonstrated a remarkable TOF as high as 735 h–1. In addition, a hypothetical catalytic reaction mechanism was proposed based on density functional theory (DFT) calculations and the catalytic reaction results of the (salen-4)[Co(III)TFA]2.

Silica supported Schiff-base cobaltIII complex-Lewis base system: a highly selective catalyst for alternating copolymerization of CO2 and propylene oxide

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Yongsheng Niu ◽  
Hongchun Li
Keyword(s):  
Molecular Weight ◽  
Schiff Base ◽  
Reaction Time ◽  
Propylene Oxide ◽  
Cobalt Complex ◽  
Catalyst System ◽  
Cyclic Carbonate ◽  
Lewis Base ◽  
Molar Ratio ◽  
Base System

AbstractAn binary catalyst system of a silica supported Schiff-base cobalt complex SalenCoIII (OAC)-MCM-41 (Salen = 3-[N,N-bis-2-(3,5-di-tert-butylsalicylidenamino) ethyl] amine) was developed to generate the copolymerization of CO2 and propylene oxide in presence of (4-dimethylamino)-pyridine (DMAP). The influence of the molar ratio of catalyst components, the operating temperature, reaction time, and CO2 pressure on the yield as well as the molecular weight of polycarbonate was systematically investigated. The high selectivity of polycarbonate over cyclic carbonate at 40 °C was maintained after a longer reaction time to attain quantitative formation of the alternating copolymer. High molecular weight of 67 000 were achieved at an appropriate combination of all variables.

Aluminum porphyrin complexes via delicate ligand design: emerging efficient catalysts for high molecular weight poly(propylene carbonate)

RSC Advances ◽  
2014 ◽  
Vol 4 (96) ◽  
pp. 54043-54050 ◽  
Author(s):  
Xingfeng Sheng ◽  
Yong Wang ◽  
Yusheng Qin ◽  
Xianhong Wang ◽  
Fosong Wang
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Ligand Design ◽  
Poly Propylene ◽  
High Molecular Weight Poly

Due to the deep concern over residual, toxic cobalt or chromium, bifunctional aluminum porphyrin complexes were prepared to catalyze the copolymerization of propylene oxide and carbon dioxide.

Mesoporous carbon nitride grafted with n-bromobutane: a high-performance heterogeneous catalyst for the solvent-free cycloaddition of CO2 to propylene carbonate

2015 ◽  
Vol 5 (1) ◽  
pp. 447-454 ◽  
Author(s):  
Jie Xu ◽  
Fei Wu ◽  
Quan Jiang ◽  
Yong-Xin Li
Keyword(s):  
Catalytic Activity ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Mesoporous Carbon ◽  
High Performance ◽  
Carbon Nitride ◽  
Maximum Yield ◽  
Solvent Free ◽  
High Catalytic Activity ◽  
Mesoporous Carbon Nitride

Mesoporous carbon nitride grafted n-bromobutane shows high catalytic activity in the solvent-free cycloaddition of CO2 with propylene oxide to propylene carbonate, affording a maximum yield of 88% with a TOF up to 10.7 h−1.

Natural amino acids/H2O as a metal- and halide-free catalyst system for the synthesis of propylene carbonate from propylene oxide and CO2under moderate conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (78) ◽  
pp. 41266-41270 ◽  
Author(s):  
Jose Tharun ◽  
Kuruppathparambil Roshith Roshan ◽  
Amal Cherian Kathalikkattil ◽  
Dong-Heon Kang ◽  
Hyun-Mo Ryu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Propylene Carbonate ◽  
Catalytic System ◽  
Propylene Oxide ◽  
Catalyst System ◽  
Natural Amino Acids

Amino acid/H2O catalytic system (metal- and halide-free) for the synthesis of propylene carbonate from propylene oxide and CO2.

Graphene oxide immobilized with ionic liquids: facile preparation and efficient catalysis for solvent-free cycloaddition of CO2 to propylene carbonate

RSC Advances ◽  
2015 ◽  
Vol 5 (88) ◽  
pp. 72361-72368 ◽  
Author(s):  
Jie Xu ◽  
Mang Xu ◽  
Jing Wu ◽  
Hao Wu ◽  
Wei-Hong Zhang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Graphene Oxide ◽  
Catalytic Activity ◽  
Ionic Liquids ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Solvent Free ◽  
High Catalytic Activity ◽  
Graphene Oxides ◽  
Facile Preparation

Graphene oxides were grafted with functionalized ionic liquid and showed high catalytic activity in cycloaddition of CO2 with propylene oxide to propylene carbonate.

Electronic Structure Benchmark Calculations of Inorganic and Biochemical Carboxylation Reactions

2018 ◽  
Author(s):  
Oscar A. Douglas-Gallardo ◽  
David A. Sáez ◽  
Stefan Vogt-Geisse ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Electronic Structure ◽  
Chemical Reactions ◽  
Density Functional ◽  
Correlation Energy ◽  
Electronic Energy ◽  
Basis Sets ◽  
Electronic Correlation ◽  
Correct Description ◽  
Carbon Dioxide Co2 ◽  
High Level

<div><div><div><p>Carboxylation reactions represent a very special class of chemical reactions that is characterized by the presence of a carbon dioxide (CO2) molecule as reactive species within its global chemical equation. These reactions work as fundamental gear to accomplish the CO2 fixation and thus to build up more complex molecules through different technological and biochemical processes. In this context, a correct description of the CO2 electronic structure turns out to be crucial to study the chemical and electronic properties associated with this kind of reactions. Here, a sys- tematic study of CO2 electronic structure and its contribution to different carboxylation reaction electronic energies has been carried out by means of several high-level ab-initio post-Hartree Fock (post-HF) and Density Functional Theory (DFT) calculations for a set of biochemistry and inorganic systems. We have found that for a correct description of the CO2 electronic correlation energy it is necessary to include post-CCSD(T) contributions (beyond the gold standard). These high-order excitations are required to properly describe the interactions of the four π-electrons as- sociated with the two degenerated π-molecular orbitals of the CO2 molecule. Likewise, our results show that in some reactions it is possible to obtain accurate reaction electronic energy values with computationally less demanding methods when the error in the electronic correlation energy com- pensates between reactants and products. Furthermore, the provided post-HF reference values allowed to validate different DFT exchange-correlation functionals combined with different basis sets for chemical reactions that are relevant in biochemical CO2 fixing enzymes.</p></div></div></div>

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