Energy Upconversion Using Platinum(II)-BPI Photosensitizers
Energy Upconversion Using Platinum(II)-BPI Photosensitizers
Five heteroleptic Pt(II) complexes structurally defined by a diethyl-substituted bis(2-pyridylimino)isoindoline (BPIEt) core and an ancillary alkynyl coligand are reported. Structural variation across Pt(BPIEt)(1–5) was achieved through different alkyne coligands: phenylacetylene (1), 4-ethynylanisole (2), 3-ethynylthiophene (3), 1-ethynyl-4-fluorobenzene (4), 1-ethynyl-4-dimethylaniline (5). Complexes were fully characterized using a range of spectroscopic and analytical techniques: 1H and 13C NMR, IR, UV–vis, luminescence, and transient absorption spectroscopies, HRMS, and cyclic voltammetry. Two X-ray structures revealed a subtle deviation from idealized square planar geometry where the Pt atom lies within the plane defined by the three nitrogen donors of BPIEt. The redox behavior of the complexes showed one irreversible oxidation between +0.61 and +0.82 V (attributed to Pt2+/3+ couple) and two well-defined ligand-based reductions with fully or quasi-reversible character between −1.70 and −2.09 V. Photophysical studies and supporting DFT calculations describe the phosphorescent nature of the complexes (λem = 625–644 nm in toluene) with strong metal-to-ligand charge transfer (MLCT) character and notable singlet oxygen photogeneration (up to 73%). Triplet–triplet annihilation energy upconversion (TTA-UC) investigations in toluene indicated that this class of triplet emitting complex are viable photosensitizers with an impressive maximum efficiency of ΦUC = 29.6% for Pt(BPIEt)(4).
24851-24864
Payce, Ellie N.
7e2ff043-655e-4499-98c1-4e934e1a8441
Wang, Dantong
340a9b9c-b954-4d8d-a9e5-7152f13f083d
Zhao, Jianzhang
08415724-251c-475a-97d7-bb21408eb959
Horton, Peter N.
154c8930-bfc3-495b-ad4a-8a278d5da3a5
Coles, Simon J.
3116f58b-c30c-48cf-bdd5-397d1c1fecf8
Platts, James A.
2df1575c-ebd8-4dac-af9e-1590b47f0a73
Pope, Simon J.A.
3004819f-2114-432d-a4b3-ce0c0d4eb4d8
22 December 2025
Payce, Ellie N.
7e2ff043-655e-4499-98c1-4e934e1a8441
Wang, Dantong
340a9b9c-b954-4d8d-a9e5-7152f13f083d
Zhao, Jianzhang
08415724-251c-475a-97d7-bb21408eb959
Horton, Peter N.
154c8930-bfc3-495b-ad4a-8a278d5da3a5
Coles, Simon J.
3116f58b-c30c-48cf-bdd5-397d1c1fecf8
Platts, James A.
2df1575c-ebd8-4dac-af9e-1590b47f0a73
Pope, Simon J.A.
3004819f-2114-432d-a4b3-ce0c0d4eb4d8
Payce, Ellie N., Wang, Dantong, Zhao, Jianzhang, Horton, Peter N., Coles, Simon J., Platts, James A. and Pope, Simon J.A.
(2025)
Energy Upconversion Using Platinum(II)-BPI Photosensitizers.
Inorganic Chemistry, 64 (50), .
(doi:10.1021/acs.inorgchem.5c04677).
Abstract
Five heteroleptic Pt(II) complexes structurally defined by a diethyl-substituted bis(2-pyridylimino)isoindoline (BPIEt) core and an ancillary alkynyl coligand are reported. Structural variation across Pt(BPIEt)(1–5) was achieved through different alkyne coligands: phenylacetylene (1), 4-ethynylanisole (2), 3-ethynylthiophene (3), 1-ethynyl-4-fluorobenzene (4), 1-ethynyl-4-dimethylaniline (5). Complexes were fully characterized using a range of spectroscopic and analytical techniques: 1H and 13C NMR, IR, UV–vis, luminescence, and transient absorption spectroscopies, HRMS, and cyclic voltammetry. Two X-ray structures revealed a subtle deviation from idealized square planar geometry where the Pt atom lies within the plane defined by the three nitrogen donors of BPIEt. The redox behavior of the complexes showed one irreversible oxidation between +0.61 and +0.82 V (attributed to Pt2+/3+ couple) and two well-defined ligand-based reductions with fully or quasi-reversible character between −1.70 and −2.09 V. Photophysical studies and supporting DFT calculations describe the phosphorescent nature of the complexes (λem = 625–644 nm in toluene) with strong metal-to-ligand charge transfer (MLCT) character and notable singlet oxygen photogeneration (up to 73%). Triplet–triplet annihilation energy upconversion (TTA-UC) investigations in toluene indicated that this class of triplet emitting complex are viable photosensitizers with an impressive maximum efficiency of ΦUC = 29.6% for Pt(BPIEt)(4).
Text
energy-upconversion-using-platinum(ii)-bpi-photosensitizers
- Version of Record
More information
Accepted/In Press date: 5 December 2025
e-pub ahead of print date: 10 December 2025
Published date: 22 December 2025
Additional Information:
Publisher Copyright:
© 2025 The Authors. Published by American Chemical Society
Identifiers
Local EPrints ID: 508659
URI: http://eprints.soton.ac.uk/id/eprint/508659
ISSN: 0020-1669
PURE UUID: 287d2bb6-0066-471f-b2cb-591bf64a82a3
Catalogue record
Date deposited: 28 Jan 2026 18:13
Last modified: 29 Jan 2026 02:48
Export record
Altmetrics
Contributors
Author:
Ellie N. Payce
Author:
Dantong Wang
Author:
Jianzhang Zhao
Author:
Peter N. Horton
Author:
James A. Platts
Author:
Simon J.A. Pope
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics