The quantum yield for the release of leaving groups from o-nitrobenzyl “caged” compounds varies greatly with the nature of these leaving groups, for reasons that have never been well understood. We found that the barriers for the primary hydrogen-atom transfer step and the efficient nonradiative processes on the excited singlet and triplet surfaces determine the quantum yields. The...
To elucidate the multifaceted but poorly understood chemistry of the pivotal polysulfur−nitrogen heterocycle, tetrasulfur tetranitride (S₄N₄, 1), its photochemistry was studied in Ar matrices. Thereby two primary intermediates and a secondary one (2−4) were detected, and their UV−vis and IR spectra were identified through specific interconversions of...