title: Iridium(III) Complexes Bearing Pyrene-Functionalized 1,10-Phenanthroline Ligands as Highly Efficient Sensitizers for Triplet-Triplet Annihilation Upconversion.
abstract: "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 IrIII-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: λabs=481 nm, ϵ=52 400 m-1cm-1) and long-lived triplet excited states (e.g. 5-substituted Ir-2: τT=367.7 μs) were observed for the complexes in deaerated CH2Cl2. On testing the series as triplet sensitizers for triplet-triplet annihilation upconversion, those IrIIIcomplexes 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).
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Junsi
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Niamh
authors.initials: N
authors.lastname: McGoldrick
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China.
authors.forename: Xiaoneng
authors.initials: X
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China.
authors.forename: Jianzhang
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Colin
authors.initials: C
authors.lastname: Caverly
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Brendan
authors.initials: B
authors.lastname: Twamley
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Gearoid M
authors.initials: GM
authors.lastname: Ó Máille
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Bryan
authors.initials: B
authors.lastname: Irwin
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Robert
authors.initials: R
authors.lastname: Conway-Kenny
authors.affiliation: Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Sylvia M
authors.identifier: 0000-0003-1323-7245
authors.initials: SM
authors.lastname: Draper
keywords: iridium(III); phenanthroline; pyrene; triplet-triplet annihilation; upconversion