Polycationic Ru(II) luminophores: syntheses, photophysics, and application in electrostatically driven sensitization of lanthanide luminescence
Polycationic Ru(II) luminophores: syntheses, photophysics, and application in electrostatically driven sensitization of lanthanide luminescence
A series of photoluminescent Ru(II) polypyridine complexes have been synthesized in a manner that varies the extent of the cationic charge. Two ligand systems (L1 and L2), based upon 2,2′-bipyridine (bipy) mono- or difunctionalized at the 5- or 5,5′-positions using N-methylimidazolium groups, were utilized. The resulting Ru(II) species therefore carried +3, +4, +6, and +8 complex moieties based on a [Ru(bipy)3]2+ core. Tetra-cationic [Ru(bipy)2(L2)][PF6]4 was characterized using XRD, revealing H-bonding interactions between two of the counteranions and the cationic unit. The ground-state features of the complexes were found to closely resemble those of the parent unfunctionalized [Ru(bipy)3]2+ complex. In contrast, the excited state properties produce a variation in emission maxima, including a bathochromic 44 nm shift of the 3MLCT band for the tetra-cationic complex; interestingly, further increases in overall charge to +6 and +8 produced a hypsochromic shift in the 3MLCT band. Supporting DFT calculations suggest that the trend in emission behavior may, in part, be due to the precise nature of the LUMO and its localization. The utility of a photoactive polycationic Ru(II) complex was then demonstrated through the sensitization of a polyanionic Yb(III) complex in free solution. The study shows that electrostatically driven ion pairing is sufficient to facilitate energy transfer between the 3MLCT donor state of the Ru(II) complex and the accepting 2F5/2 excited state of Yb(III).
19446-19456
Knighton, Richard C.
5a63128e-0ebd-466a-b327-3aee6e85a76d
Beames, Joseph M.
73b04545-4859-44ad-999e-551f82924c29
J.A. Pope, Simon
05baa6a4-34a2-428b-ae52-003e2c25c80e
4 December 2023
Knighton, Richard C.
5a63128e-0ebd-466a-b327-3aee6e85a76d
Beames, Joseph M.
73b04545-4859-44ad-999e-551f82924c29
J.A. Pope, Simon
05baa6a4-34a2-428b-ae52-003e2c25c80e
Knighton, Richard C., Beames, Joseph M. and J.A. Pope, Simon
(2023)
Polycationic Ru(II) luminophores: syntheses, photophysics, and application in electrostatically driven sensitization of lanthanide luminescence.
Inorganic Chemistry, 62 (48), .
(doi:10.1021/acs.inorgchem.3c02352).
Abstract
A series of photoluminescent Ru(II) polypyridine complexes have been synthesized in a manner that varies the extent of the cationic charge. Two ligand systems (L1 and L2), based upon 2,2′-bipyridine (bipy) mono- or difunctionalized at the 5- or 5,5′-positions using N-methylimidazolium groups, were utilized. The resulting Ru(II) species therefore carried +3, +4, +6, and +8 complex moieties based on a [Ru(bipy)3]2+ core. Tetra-cationic [Ru(bipy)2(L2)][PF6]4 was characterized using XRD, revealing H-bonding interactions between two of the counteranions and the cationic unit. The ground-state features of the complexes were found to closely resemble those of the parent unfunctionalized [Ru(bipy)3]2+ complex. In contrast, the excited state properties produce a variation in emission maxima, including a bathochromic 44 nm shift of the 3MLCT band for the tetra-cationic complex; interestingly, further increases in overall charge to +6 and +8 produced a hypsochromic shift in the 3MLCT band. Supporting DFT calculations suggest that the trend in emission behavior may, in part, be due to the precise nature of the LUMO and its localization. The utility of a photoactive polycationic Ru(II) complex was then demonstrated through the sensitization of a polyanionic Yb(III) complex in free solution. The study shows that electrostatically driven ion pairing is sufficient to facilitate energy transfer between the 3MLCT donor state of the Ru(II) complex and the accepting 2F5/2 excited state of Yb(III).
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Polycationic IC revision_RCK01
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knighton-et-al-2023-polycationic-ru(ii)-luminophores-syntheses-photophysics-and-application-in-electrostatically-driven
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Accepted/In Press date: 3 November 2023
e-pub ahead of print date: 20 November 2023
Published date: 4 December 2023
Additional Information:
Funding Information:
Financial support from the Leverhulme Trust (RPG-2021-003) is gratefully acknowledged. We acknowledge the use of the EPSRC-funded Physical Sciences Data-science Service hosted by the University of Southampton and STFC under grant no. EP/S020357/1.
Publisher Copyright:
© 2023 The Authors. Published by American Chemical Society.
Identifiers
Local EPrints ID: 485104
URI: http://eprints.soton.ac.uk/id/eprint/485104
ISSN: 0020-1669
PURE UUID: d9eb265f-385a-439a-ab41-708ca5591662
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Date deposited: 29 Nov 2023 17:52
Last modified: 18 Mar 2024 04:15
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Author:
Richard C. Knighton
Author:
Joseph M. Beames
Author:
Simon J.A. Pope
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