Publication

Intramolecular Energy and Electron Transfers in Bodipy-Naphthalenediimide Triads

Intramolecular Energy and Electron Transfers in Bodipy-Naphthalenediimide Triads
Mushraf Hussain, Ahmed M. El-Zohry, Habtom B. Gobeze, Jianzhang Zhao, Francis D'Souza, Omar F. Mohammed
The Journal of Physical Chemistry A
Mushraf Hussain, Ahmed M. El-Zohry, Habtom B. Gobeze, Jianzhang Zhao, Francis D'Souza, Omar F. Mohammed
Förster Resonance Energy Transfer
2018


Borondipyrromethene (BDP) naphthalenediimide (NDI) triads (BDP-NDI) and Diiodo-BDP derivative (DiiodoBDP-NDI)) were synthesized to study the Förster Resonance Energy Transfer (FRET) and its impact on the triplet state formation and dynamics. In these triads, Diiodo-BDP and BDP are the energy donors and NDI is the energy accepter. Nanosecond transient absorption spectra of triads indicated that triplet state is localized on NDI moiety, either by selective photoexcitation of the Diiodo-BDP or NDI unit. The intersystem crossing (ISC) is attributed to intramolecular heavy atom effect. The triplet state quantum yield was found to be 54 % with a lifetime of 38 microseconds. On the other hand, no triplet state is observed for BDP-NDI system either by exciting BDP or NDI unit. Thus we confirmed that charge recombination does not produce triplet state. Interestingly, DiiodoBDP-NDI can be used as broadband excitable (500 ~ 620 nm) triplet photosensitizer and high triplet–triplet annihilation (TTA) upconversion quantum yield of 2.8 % was observed with 9,10-bis(phenylethynyl)-anthracene (BPEA) as a triplet accepter/emitter.​
DOI: 10.1021/acs.jpca.8b03884