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Iridium(III) Complexes Bearing Pyrene‐Functionalized 1,10‐Phenanthroline Ligands as Highly Efficient Sensitizers for Triplet–Triplet Annihilation Upconversion
Author(s) -
Lu Yue,
Wang Junsi,
McGoldrick Niamh,
Cui Xiaoneng,
Zhao Jianzhang,
Caverly Colin,
Twamley Brendan,
Ó Máille Gearoid M.,
Irwin Bryan,
ConwayKenny Robert,
Draper Sylvia M.
Publication year - 2016
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201608442
Subject(s) - iridium , photon upconversion , pyrene , photochemistry , chemistry , excited state , phosphorescence , phenanthroline , sonogashira coupling , quantum yield , fluorescence , annihilation , crystallography , palladium , atomic physics , organic chemistry , physics , ion , quantum mechanics , catalysis
“Chemistry‐on‐the‐complex” synthetic methods have allowed the selective addition of 1‐ethynylpyrene appendages to the 3‐, 5‐, 3,8‐ and 5,6‐positions of Ir III ‐coordinated 1,10‐phenanthroline via Sonogashira cross‐coupling. The resulting suite of complexes has given rise to the first rationalization of their absorption and emission properties as a function of the number and position of the pyrene moieties. Strong absorption in the visible region (e.g. 3,8‐substituted Ir‐3 : λ abs =481 nm, ϵ=52 400 m −1 cm −1 ) and long‐lived triplet excited states (e.g. 5‐substituted Ir‐2 : τ T =367.7 μs) were observed for the complexes in deaerated CH 2 Cl 2 . On testing the series as triplet sensitizers for triplet–triplet annihilation upconversion, those Ir III complexes bearing pyrenyl appendages at the 3‐ and 3,8‐positions ( Ir‐1 , Ir‐3 ) were found to give optimal upconversion quantum yields (30.2 % and 31.6 % respectively).