To validate our molecular design concept, we synthesized photocleavable coumarin derivatives bearing silyl groups and examined their hydrolytic resistances and photocleavage efficiencies. We synthesized compound 3 (denoted as Si-Carb 3) with TMS groups located adjacent to the photolytic cleavage site, as well as the unmodified reference compound 2, denoted as Carb 2. In addition to the carbamate version of coumarin derivatives, we synthesized the ester version of coumarins 1 (also denoted as Ester 1) as the most widely used reference compound (Figure ).