화학공학소재연구정보센터
Inorganic Chemistry, Vol.51, No.15, 7957-7959, 2012
Metal Coordination Induced pi-Extension and Triplet State Production in Diketopyrrolopyrrole Chromophores
Triplet state photophysics has been generated in two distinct diketopyrrolopyrrole (DPP) chromophores terminated with either phenyl (1) or thienyl (2) spacers, when sandwiched between two Ir(III) complexes using bipyridyl linkers. Upon coordination of the bpy-DPP-bpy subunit resulting in its planarization, the pi-conjugation in the DPP chromophore formally extends and was manifested as a substantial red shift in the absorption and fluorescence profiles of 1 and 2. Low energy excitation of these dinuclear metal complexes produced strongly quenched singlet fluorescence, generated quite intense long-lived (tau similar to 3 mu s) absorption transients in the red, sensitized O-1(2) photoluminescence centered at 1270 nm in aerated solutions, and yielded low temperature near-IR phosphorescence in 1 centered at 950 nm.