Indexed by:期刊论文

Date of Publication:2017-03-01

Journal:JOURNAL OF LUMINESCENCE

Included Journals:SCIE、EI

Volume:183

Page Number:507-512

ISSN No.:0022-2313

Key Words:hexaphenylbiimidazole (HPBI); Photochromism; photoswitching; triplet-triplet annihilation (TTA) upconversion; triplet state

Abstract:Photoirradiation generated radical from hexaphenyl-biimidazole (HPBI) was used for reversible switching of triplet-triplet annihilation (TTA) upconversion, based on quenching of the photosensitizer triplet state by radical-triplet pair mechanism. Upon 365 nm irradiation, the TTA upconversion in a system composed by a boron-dipyrromethene (BODIPY) derivative and perylene, was completely switched off due to quenching of triplet state of photosensitizer by photogenerated radical from HPBI. The upconversion was recovered after leaving the samples in darkness, due to regeneration of HPBI Dimer. The photophysical process involved in the photochromism and photoswitching of TTA upconversion were studied with steady-state UVvis absorption spectroscopy, nanosecond transient absorption spectroscopy and EPR spectroscopy. (C) 2016 Elsevier B.V. All rights reserved.