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Payce EN, Knighton RC, Platts JA, Horton PN, Coles SJ, Pope SJA. Luminescent Pt(II) Complexes Using Unsymmetrical Bis(2-pyridylimino)isoindolate Analogues. Inorg Chem 2024; 63:8273-8285. [PMID: 38656154 PMCID: PMC11080048 DOI: 10.1021/acs.inorgchem.4c00558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/26/2024]
Abstract
A series of ligands based upon a 1,3-diimino-isoindoline framework have been synthesized and investigated as pincer-type (N∧N∧N) chelates for Pt(II). The synthetic route allows different combinations of heterocyclic moieties (including pyridyl, thiazole, and isoquinoline) to yield new unsymmetrical ligands. Pt(L1-6)Cl complexes were obtained and characterized using a range of spectroscopic and analytical techniques: 1H and 13C NMR, IR, UV-vis and luminescence spectroscopies, elemental analyses, high-resolution mass spectrometry, electrochemistry, and one example via X-ray crystallography which showed a distorted square planar environment at Pt(II). Cyclic voltammetry on the complexes showed one irreversible oxidation between +0.75 and +1 V (attributed to Pt2+/3+ couple) and a number of ligand-based reductions; in four complexes, two fully reversible reductions were noted between -1.4 and -1.9 V. Photophysical studies showed that Pt(L1-6)Cl absorbs efficiently in the visible region through a combination of ligand-based bands and metal-to-ligand charge-transfer features at 400-550 nm, with assignments supported by DFT calculations. Excitation at 500 nm led to luminescence (studied in both solutions and solid state) in all cases with different combinations of the heterocyclic donors providing tuning of the emission wavelength around 550-678 nm.
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Affiliation(s)
- Ellie N Payce
- School of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, Cymru/Wales, U.K
| | - Richard C Knighton
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, England, U.K
| | - James A Platts
- School of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, Cymru/Wales, U.K
| | - Peter N Horton
- UK National Crystallographic Service, Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, England, U.K
| | - Simon J Coles
- UK National Crystallographic Service, Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, England, U.K
| | - Simon J A Pope
- School of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, Cymru/Wales, U.K
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Zeitler HE, Phearman AS, Gau MR, Carroll PJ, Cundari TR, Goldberg KI. Metal-Ligand-Anion Cooperation in C-H Bond Formation at Platinum(II). J Am Chem Soc 2022; 144:14446-14451. [PMID: 35881991 DOI: 10.1021/jacs.2c05096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermolysis of [H(BPI)Pt(CH3)][OTf] (BPI = 1,3-bis(2-(4-tert-butyl)pyridylimino)isoindole) to release methane and form (BPI)Pt(OTf) is reported. Kinetic, mechanistic, and computational studies point to an unusual anion-assisted pathway that obviates the need for a higher oxidation state intermediate to couple the metal-bound methyl group with the ligand-bound hydrogen. Leveraging this insight, a triflimide derivative of the (BPI)Pt complex was shown to activate benzene, highlighting the role of the counteranion in controlling the activity of these complexes.
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Affiliation(s)
- Hannah E Zeitler
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Alexander S Phearman
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Michael R Gau
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patrick J Carroll
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Thomas R Cundari
- Department of Chemistry and Center for Advanced Scientific Computing and Modeling, University of North Texas, Denton, Texas 76203, United States
| | - Karen I Goldberg
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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