Work

Latency and Immobilization in Silicone Resin by (NHC)Pt(dvtms) Complexes through a Partially Self-Consuming Ligand

Year: 2024

Type: article

Abstract: Silicones have a plethora of uses but have limitations in placement errors and continuous cross-linking. To address these challenges, we sought to develop a catalyst that would not only contain a latency period, thereby limiting placement errors but could be immobilized in an elastomer, thus thwarting continued cross-linking. Five new N -heterocyclic carbene ligands were synthesized to feature alkene pendant arms of various lengths, (1,3-di(pent-4-en-1-yl)-1 H -imidazol-3-ium bromide ([ C5 Im]Br ), 1,3-di(but-3-en-1-yl)-1 H -imidazol-3-ium bromide ( [ C4 Im]Br ), and sterics (1-(2,6-diisopropylphenyl)-3-(pent-4-en-1-yl)-1 H -imidazol-3-ium bromide ( [ C5 Im Dipp ]Br ), and 1-methyl-3-pent-4-en-1-yl)-1 H -imidazol-3-ium bromide ( [ C5 Im Me ]Br ) were targeted to understand how alkene length influences latency. An alkane version of the ligand (1,3-dipentyl-1 H -imidazol-3-ium bromide ( [ C5 sat Im]Br ) was also developed for comparison. Upon deprotonation and subsequent reaction of the ligand with Karstedt’s catalyst, a new family of Markó’s catalysts were developed. Stoichiometric reactions with silanes demonstrated that the pendant ligand arms can be hydrosilylated. Immobilization of the catalyst via intramolecular hydrosilylation effectively prevented post-cure cross-linking.

Source: Organometallics

DOI: 10.1021/acs.organomet.3c00456

Authors: Ericka L. Bruske, Nicholas D. Maldonado, Matthew S. Jeletic, Alison R. Fout

Institutions: University of Illinois Urbana-Champaign, Texas A&M University

Language: English

Topic: N-Heterocyclic Carbenes in Organic and Inorganic Chemistry

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Dow Chemical Company