Tunable meso-tetraphenyl-alkyloxazolo-chlorins and -bacteriochlorins

Alkyl-Grignard addition to meso-tetraphenylporpholactone generates monoalkyl- and gem-bis-alkyloxazolochlorins. Together with compounds made by further synthetic manipulations of these derivatives, a series of chlorin-type chromophores with modulated optical properties is generated. Furthermore, their OsO(4)-mediated dihydroxylations and subsequent functional group transformations generate a family of bacteriochlorins that possess substituent-dependent optical properties. Thus, the formal replacement of a pyrrolidine moiety in chlorins and bacteriochlorins by variously substituted oxazoles is a flexible methodology to generate novel and stable chromophores that are tunable over a considerable range of the optical spectrum.