Perfectly Alternating Copolymerization of CO and Epoxides to Aliphatic Polyester Oligomers via Cooperative Organoboron–Cobalt Complexes

2021 ◽  
Author(s):  
Yao-Yao Zhang ◽  
Li Yang ◽  
Rui Xie ◽  
Guan-Wen Yang ◽  
Guang-Peng Wu
Keyword(s):  
Cobalt Complexes ◽  
Aliphatic Polyester ◽  
Alternating Copolymerization

scholarly journals Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

2018 ◽  
Vol 14 ◽  
pp. 2779-2788 ◽  
Author(s):  
Yo Hiranoi ◽  
Koji Nakano
Keyword(s):  
Catalytic Activity ◽  
Cobalt Complex ◽  
Cobalt Complexes ◽  
High Catalytic Activity ◽  
Synthetic Method ◽  
Salen Complex ◽  
Salen Complexes ◽  
Mononuclear Cobalt ◽  
Cyclic Anhydrides ◽  
Alternating Copolymerization

The alternating copolymerization of epoxides with cyclic anhydrides (CAs) is a highly diverse synthetic method for polyesters as the polymers’ architectures and properties can be easily controlled depending on the combination of two monomers. Thus, a variety of catalyst designs has been reported to prepare the desired copolymers efficiently. We herein report dinuclear cobalt–salen complexes with a benzene ring as a linker and their activities in copolymerization reactions. The dinuclear cobalt complexes showed a higher catalytic activity for the copolymerization of propylene oxide with phthalic anhydride than the corresponding mononuclear cobalt–salen complex and achieved one of the highest turnover frequencies ever reported. A variety of epoxides and CAs were also found to be copolymerized successfully by the dinuclear cobalt complex with a high catalytic activity.

Cobaloxime-Based Double Complex Salts as Efficient and Versatile Catalysts for the Light-Driven Hydrogen Evolution Reaction

2020 ◽  
Author(s):  
Elisabeth Hofmeister ◽  
Jisoo Woo ◽  
Tobias Ullrich ◽  
Lydia Petermann ◽  
Kevin Hanus ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Systematic Study ◽  
Cobalt Complexes ◽  
Spectroscopic Studies ◽  
Double Complex ◽  
Double Complex Salts ◽  
Noble Metal Catalysts ◽  
Reduction Potentials ◽  
Complex Salts

Cobaloximes and their BF<sub>2</sub>-bridged analogues have emerged as promising non-noble metal catalysts for the photocatalytic hydrogen evolution reaction (HER). Herein we report the serendipitous discovery that double complex salts such as [Co(dmgh)<sub>2</sub>py<sub>2</sub>]<sup>+</sup>[Co(dmgBPh<sub>2</sub>)<sub>2</sub>Cl<sub>2</sub>]<sup>-</sup> can be obtained in good yields by treatment of commercially available [Co(dmgh)<sub>2</sub>pyCl] with triarylboranes. A systematic study on the use of such double complex salts and their single salts with simple counterions as photocatalysts revealed HER activities comparable or superior to existing cobaloxime catalysts and suggests ample opportunities for this compound class in catalyst/photosensitizer dyads and immobilized architectures. Preliminary electrochemical and spectroscopic studies indicate that one key advantage of these charged cobalt complexes is that the reduction potentials as well as the electrostatic interaction with charged photosensitizers can be tuned.

scholarly journals Paramagnetic solid-state NMR assignment and novel chemical conversion of the aldehyde group to dihydrogen ortho ester and hemiacetal moieties in copper(ii)- and cobalt(ii)-pyridinecarboxaldehyde complexes

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20216-20231
Author(s):  
Ayelén F. Crespi ◽  
Verónica M. Sánchez ◽  
Daniel Vega ◽  
Ana L. Pérez ◽  
Carlos D. Brondino ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Assignment ◽  
Cobalt Complexes ◽  
Chemical Conversion ◽  
Aldehyde Group ◽  
Ortho Ester ◽  
Complex Chemical ◽  
Chemical Functionalization

The complex chemical functionalization of the aldehyde group was elucidated in copper and cobalt complexes for 4- and 3-pyridinecarboxaldehyde ligands.

scholarly journals Structural, Magnetic, and Electrochemical Characterization of Iron(III) and Cobalt Complexes with Penta‐N 3 O 2 ‐dentate Ligands

2021 ◽  
Vol 2021 (15) ◽  
pp. 1498-1504
Author(s):  
Dominik Natke ◽  
Annika Preiss ◽  
Stephen Klimke ◽  
Takuya Shiga ◽  
Roman Boca ◽  
...  
Keyword(s):  
Cobalt Complexes ◽  
Electrochemical Characterization

Engineering 3D printed bioactive composite scaffolds based on the combination of aliphatic polyester and calcium phosphates for bone tissue regeneration

2021 ◽  
Vol 122 ◽  
pp. 111928
Author(s):  
Eduardo H. Backes ◽  
Emanuel M. Fernandes ◽  
Gabriela S. Diogo ◽  
Catarina F. Marques ◽  
Tiago H. Silva ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Tissue Regeneration ◽  
Calcium Phosphates ◽  
Bone Tissue Regeneration ◽  
Aliphatic Polyester ◽  
Composite Scaffolds ◽  
3D Printed

Chiral salenCo(iii) complexes with bulky substituents as catalysts for stereoselective alternating copolymerization of racemic propylene oxide with carbon dioxide and succinic anhydride

2021 ◽  
Vol 12 (12) ◽  
pp. 1776-1786
Author(s):  
Zhou Wang ◽  
Ying Mu
Keyword(s):  
Carbon Dioxide ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Succinic Anhydride ◽  
Poly Propylene ◽  
Alternating Copolymerization

Stereoregular poly(propylene carbonate)s and poly(propylene succinate-block-carbonate)s were synthesized with new chiral salenCo(iii) catalysts carrying bulky substituents.

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