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Cationic indium catalysts for ring opening polymerization: tuning reactivity with hemilabile ligands.

ABSTRACT: This is a comprehensive study of the effects of rationally designed hemilabile ligands on the stability, reactivity, and change in catalytic behavior of indium complexes. We report cationic alkyl indium complexes supported by a family of hemi-salen type ligands bearing hemilabile thiophenyl (2a), furfuryl (2b) and pyridyl (2c) pendant donor arms. Shelf-life and stability of these complexes followed the trend 2a < 2b < 2c, showing direct correlation to the affinity of the pendant donor group to the indium center. Reactivity towards polymerization of epichlorohydrin and cyclohexene oxide followed the trend 2a > 2b > 2c with control of polymerization following an inverse relationship to reactivity. Surprisingly, 2c polymerized racemic lactide without an external initiator, likely through an alkyl-initiated coordination-insertion mechanism.

SUBMITTER: Goonesinghe C

PROVIDER: S-EPMC8159295 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

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Cationic indium catalysts for ring opening polymerization: tuning reactivity with hemilabile ligands.

Goonesinghe Chatura C Roshandel Hootan H Diaz Carlos C Jung Hyuk-Joon HJ Nyamayaro Kudzanai K Ezhova Maria M Mehrkhodavandi Parisa P

Chemical science 20200422 25

This is a comprehensive study of the effects of rationally designed hemilabile ligands on the stability, reactivity, and change in catalytic behavior of indium complexes. We report cationic alkyl indium complexes supported by a family of hemi-salen type ligands bearing hemilabile thiophenyl (2a), furfuryl (2b) and pyridyl (2c) pendant donor arms. Shelf-life and stability of these complexes followed the trend 2a < 2b < 2c, showing direct correlation to th ...[more]

PMID: 34094114

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