Solar cell applications of fluorous dyes: a new paradigm for light-to-energy conversion devices

My interest in fluorous chemistry emanated when the classic paper "Facile Catalyst Separation without Water: Fluorous Biphase Hydroformylation of Olefins", was published in Science in 1994, by Horvath and Rabai. The picture of a deeply blue colored phthalocyanine metal complex made soluble in an inert, non-coordinating perfluorocarbon solvent, caught my imagination, and I convinced my mentor, Prof. F. Montanari, to let me investigate fluorous molecules. This rewarding research activity has been pursued since then with the competent help of many colleagues and students, who all deserve the author's gratitude. It started with the synthesis of fluorous nitrogen ligands designed to bind metals and generate easily recoverable and recyclable pre-catalysts, most of which, were actually beautiful colored species. At the same time, the stereoelectronic effects brought about by the insertion of fluoroponytails in the structure of chiral catalysts, and the influence of fluorous reaction media on enantioselective catalytic reactions were highlighted.1 In the course of these studies, it became clear that the experience gained by studying fluorous catalysts could be also relevant in other research fields, including the development of fluorinated materials for electronic and optoelectronic applications, where the design of fluoroponytails as structural motifs, and modifiers of organic, inorganic, and polymeric compounds has great potential. Following this line of reasoning, fluorous dyes are now being investigated by the Pozzi group, as fundamental components of light-to-energy conversion devices.2 This evolution will be outlined using fluorous phthalocyanines as model compounds. Finally, another family of fluorous dyes able to act as photosensitizers in mesoscopic solar cells, will also be presented.