Spectroscopic Identification of Carbamate Formation and Synergistic Binding in Amide-CO₂ Complexes.

ABSTRACT: Carbamate formation is an elementary step that governs nitrogen-centered nucleophilic CO₂ capture across diverse environments, yet a direct, structure-specific understanding has been lacking. Here, we report the first gas-phase characterization of closed-shell carbamate formation by deprotonated amides, using cryogenic ion trap vibrational spectroscopy combined with quantum chemical calculations. Reactions of deprotonated benzamide and isophthalamide anions with CO₂ form carbamate species, with the amide nitrogen serving as the nucleophilic site. Diagnostic, strongly red-shifted antisymmetric CO₂ stretching vibrational bands, supported by a bonding analysis, establish chemisorption with substantial charge transfer. In the multiamide system, an intramolecula

SUBMITTER: Han J 

PROVIDER: S-EPMC12720224 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature