Molecular light-upconversion: we have had a problem! When excited state absorption (ESA) overcomes energy transfer upconversion (ETU) in Cr(III)/Er(III) complexes.

ABSTRACT: Nine-coordinate [ErN9] or [ErN3O6] chromophores found in triple helical [Er(L)3]3+ complexes (L corresponds to 2,2',6',2''-terpyridine (tpy), 2,6-(bisbenzimidazol-2-yl)pyridine (bzimpy), 2,6-diethylcarboxypyridine (dpa-ester) or 2,6-diethylcarboxamidopyridine (dpa-diamide) derivatives), [Er(dpa)3]3- (dpa is the 2,6-dipicolinate dianion) and [GaErGa(bpb-bzimpy)3]9+ (bpb-bzimpy is 2,6-bis((pyridin-2-benzimidazol-5-yl)methyl-(benzimidazol-2-yl))pyridine) exhibit NIR (excitation at 801 nm) into visible (emission at 542 nm) linear light upconversion processes in acetonitrile at room temperature. The associated quantum yields 5.5(6) × 10-11 ≤ φuptot(ESA) ≤ 1.7(2) × 10-9 appear to be 1-3 orders of magnitude larger than those predicted by the accepted single-center excited-state absorption mechani

SUBMITTER: Golesorkhi B 

PROVIDER: S-EPMC8204332 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature