2-Nitrobenzylarsonium Compounds That Photorelease Heavy-Atom Cholinergic Ligands for Time-Resolved Crystallographic Studies on Cholinesterases

As heavy-atom analogues of caged cholinergic ligands, the arsonium compounds 1 – 3 were synthesized for potential time-resolved crystallographic studies on cholinesterases. Compounds 1 and 3 possess the desired properties for dynamic studies on the catalytic mechanism of cholinesterases: structural similarity with the N-homologue, strong X-ray diffracting effect of arsenic, inhibitory effects on cholinesterases, and excellent photofragmentation kinetics.