Transition-State Stabilization by n→π* Interactions Measured Using Molecular Rotors
作者:Erik C. Vik、Ping Li、Perry J. Pellechia、Ken D. Shimizu
DOI:10.1021/jacs.9b08542
日期:2019.10.23
A series of 16 molecular rotors were synthesized to investigate the ability of n→π* interactions to stabilize transition states (TS) of bond rotation. Steric contributions to the rotational barrier were isolated using control rotors, which could not form n→π* interactions. Rotors with strong acceptor π* orbitals such as ketones, aldehydes, and nitriles had greatly increased rates of rotation. The TS
Analysis of the Orbital and Electrostatic Contributions to the Lone Pair–Aromatic Interaction Using Molecular Rotors
作者:Erik C. Vik、Ping Li、Daniel O. Madukwe、Ishwor Karki、Gabriel S. Tibbetts、Ken D. Shimizu
DOI:10.1021/acs.orglett.1c02878
日期:2021.11.5
The attractive interaction between carbonyl oxygens and the π-face of aromatic surfaces was studied using N-phenylimide molecular rotors. The C═O···Ar interactions could stabilize the transition states but were half the strength of comparable C═O···C═O interactions. The C═O···Ar interaction had a significant electrostatic component but only a small orbital delocalization component.