Photogeneration and Direct Observation of a 2H-phosphirene and a Closed-shell Singlet Arylphosphenium Ion.

Phosphenium ions are highly reactive species with the formula of RR'P. Although phosphenium ions were proposed as the invaluable intermediates of various important chemical processes, the methods to generate and characterize them were very limited. In this study, a novel photoprecursor to give rise to the arylphosphenium ions, 1-(naphthalen-2-yl)phosphirane, was synthesized and investigated by femtosecond to nanosecond transient absorption spectroscopies, photoproduct analysis, and density functional theory calculations.

Controllable Photocleavage of Blebbistatin Derivatives as Photoremovable Protecting Groups.

Blebbistatin was demonstrated as a promising two-photon near-infrared activated photoremovable protecting group of hydroxyl radicals with various potential applications. However, the photocleavage mechanism of the blebbistatin derivatives remains ambiguous. Herein, blebbistatin derivatives with various electronic characteristic leaving groups were synthesized and studied, and the photocleavage mechanism(s) and the tunable effect of the leaving groups were unveiled by combining photoproduct analysis, reactive oxygen radical species detection, femtosecond transient absorption spectroscopy, and density functional theory calculation.