In:
Chemistry – A European Journal, Wiley, Vol. 29, No. 9 ( 2023-02-10)
Abstract:
A series of 2‐phenylquinoxaline ligands have been synthesised that introduce either CF 3 or OCF 3 electron‐withdrawing groups at different positions of the phenyl ring. These ligands were investigated as cyclometalating reagents for platinum(II) to give neutral complexes of the form [Pt(C^N)(acac)] (in which C^N=cyclometalating ligand; acac=acetyl acetonate). X‐ray crystallographic studies on three examples showed that the complexes adopt an approximate square planar geometry. All examples revealed strong Pt−Pt linear contacts of 3.2041(6), 3.2199(3) and 3.2586(2) Å. The highly coloured complexes display efficient visible absorption at 400–500 nm (ϵ ≈5000 M −1 cm −1 ) and orange red photoluminescent characteristics ( λ em =603–620 nm; Φ em ≤37 %), which were subtly tuned by the ligand. Triplet emitting character was confirmed by microsecond luminescence lifetimes and the photogeneration of singlet oxygen with quantum efficiencies up to 57 %. Each complex was investigated as a photosensitiser for triplet–triplet annihilation energy upconversion using 9,10‐diphenylanthracene as the annihilator species: a range of good upconversion efficiencies ( Φ UC 5.9–14.1 %) were observed and shown to be strongly influenced by the ligand structure in each case.
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.202203241
Language:
English
Publisher:
Wiley
Publication Date:
2023
detail.hit.zdb_id:
1478547-X
Permalink