Positive Electrofluorochromism\nof BODIPY–Ferrocene\nMonolayers on ITO

A borondipyrromethene (BODIPY)–ferrocene dyad\nwhere both\nunits are connected by an ethynylstyryl linker was synthesized, and\nits fluorescence and electrochemical and electrofluorochromic features\nwere analyzed first in solution and then as a surface-confined species.\nImmobilization was achieved by a siloxane derivatization at the meso\nposition of the BODIPY, which enabled covalent grafting onto the ITO\nsurface. The resulting monolayer showed high stability in the redox\nresponse and positive electrofluorochromism. Fluorescent emission\nwas indeed switched on upon oxidation and monitored electrochemically,\nwith good reversibility across cycles. This demonstrated that electrofluorochromic\nproperties could be transposed from solution to the surface in the\ncase of dyads whose emission is initially quenched.