In:
Chemistry – A European Journal, Wiley, Vol. 21, No. 46 ( 2015-11-09), p. 16434-16447
Abstract:
Water‐soluble cationic alkynylplatinum(II) 2,6‐bis(benzimidazol‐2′‐yl)pyridine (bzimpy) complexes have been demonstrated to undergo supramolecular assembly with anionic polyelectrolytes in aqueous buffer solution. Metal–metal‐to‐ligand charge transfer (MMLCT) absorptions and triplet MMLCT ( 3 MMLCT) emissions have been found in UV/Vis absorption and emission spectra of the electrostatic assembly of the complexes with non‐conjugated polyelectrolytes, driven by Pt⋅⋅⋅Pt and π–π interactions among the complex molecules. Interestingly, the two‐component ensemble formed by [Pt(bzimpy‐Et){CCC 6 H 4 (CH 2 NMe 3 ‐4)}]Cl 2 ( 1 ) with para ‐linked conjugated polyelectrolyte (CPE), PPE‐SO 3 − , shows significantly different photophysical properties from that of the ensemble formed by 1 with meta ‐linked CPE, m PPE‐Ala. The helical conformation of m PPE‐Ala allows the formation of strong m PPE‐Ala– 1 aggregates with Pt⋅⋅⋅Pt, electrostatic, and π–π interactions, as revealed by the large Stern–Volmer constant at low concentrations of 1 . Together with the reasonably large Förster radius, large HOMO–LUMO gap and high triplet state energy of m PPE‐Ala to minimize both photo‐induced charge transfer (PCT) and Dexter triplet energy back‐transfer (TEBT) quenching of the emission of 1 , efficient Förster resonance energy transfer (FRET) from m PPE‐Ala to aggregated 1 molecules and strong 3 MMLCT emission have been found, while the less strong PPE‐SO 3 − – 1 aggregates and probably more efficient PCT and Dexter TEBT quenching would account for the lack of 3 MMLCT emission in the PPE‐SO 3 − – 1 ensemble.
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.201501804
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
1478547-X
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