Luminescent 2-phenylbenzothiazole cyclometalated Pt II and Ir III complexes with chelating P^O ligands
Two series of cyclometalated Pt and Ir complexes with general formulas [Pt(pbt){PPh (R)-κ , }] (2a-2c) and [Ir(pbt) {PPh (R)-κ , }] (3a-3c), where Hpbt is 2-phenylbenzothiazol and PPh (R) is a diphenylphosphino donor functionalized deprotonated acid (R = -C H CO a, -C H SO b, CH CH CO c) are present...
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Published in | Dalton transactions : an international journal of inorganic chemistry Vol. 51; no. 1; pp. 274 - 285 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
England
20.12.2021
|
Online Access | Get full text |
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Summary: | Two series of cyclometalated Pt
and Ir
complexes with general formulas [Pt(pbt){PPh
(R)-κ
,
}] (2a-2c) and [Ir(pbt)
{PPh
(R)-κ
,
}] (3a-3c), where Hpbt is 2-phenylbenzothiazol and PPh
(R) is a diphenylphosphino donor functionalized deprotonated acid (R =
-C
H
CO
a,
-C
H
SO
b, CH
CH
CO
c) are presented. The structures of 1, 2a-2c, 3a and 3b were confirmed by single X-ray diffraction analyses, and the intermolecular interactions in 2a were studied using Hirshfeld surface analysis and non-covalent interaction (NCI) methods on its X-ray structure. Their photophysical properties were investigated by absorption and emission analyses [CH
Cl
, solid (298, 77 K) and doped polystyrene (PS) films], supported by TD-DFT calculations on 1, 2a-2c and 3a. The Pt
complexes exhibit bright phosphorescence in the region 525-542 nm, ascribed to a mixed
IL/
MLCT excited state with a predominant
IL contribution. The Ir
derivatives (3a-3c) show orange photoluminescence (535-584 nm, 298 K), blue shifted at 77 K (527-560 nm), originated from the admixture of
IL/
MLCT/
LLCT excited states. Interestingly, the photoluminescence quantum yields of the Pt complexes 2a-2c (
= 46.5-66.5%) in PS films are remarkably higher than those of the corresponding iridium complexes (
= 17.3-32%) and the precursor 1 (
= 17%). The calculated
MC-
IL/
MLCT energy gap for 2a and 3a accounts for the higher quantum yield of the Pt in relation to the Ir complex. |
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ISSN: | 1477-9226 1477-9234 |
DOI: | 10.1039/D1DT03531B |