Département de chimie moléculaire

This review deals with some identified consequences of excited-state conformational relaxations on photoinduced processes taking place within semi-rigid and potentially $π$-conjugated inorg. multicomponent systems. Planarization is the hallmark of structural upheavals herein considered. This ultrafast and widespread phenomenon is shown to occur upon various types of photoinduced charge redistributions at the intramol. level, which span from mere metal-to-ligand charge transfer (MLCT) to charge sepd. (CS) state formation. Having first being reminded of the various aspects which constitute the general context of this review, that is supramol. inorg. photochem., and put in perspective the plural status of intramol. conformation, we shall assess the possible substantial changes in the photophys. features of luminophores following from planarization. Then, the impact of the excited-state planarization on the interplay between functional subunits via the modification of intercomponent electronic coupling, is discussed. Special emphasis is put on (closely coupled) dyads comprised of a photoactive coordination compd. (typically of the ruthenium(II)-trisbipyridyl or osmium(II)-bisterpyridyl type) as both the photosensitizer and the primary light-triggered electron donor, and of a substituted pyridinium group as the electron acceptor. Implementation of conformational gating of photoinduced processes for mol. electronics or sensing devices is finally mentioned. [on SciFinder(R)]