Issue 36, 2025, Issue in Progress

Cucurbit[10]uril binding of heteroleptic iridium(iii) complexes: synthesis and photophysical characterization

Abstract

The supramolecular host–guest interaction between heteroleptic iridium(III) complexes and cucurbit[10]uril (Q[10]) in an aqueous medium was investigated in this work. Both studied iridium complexes, [Ir(ppy)2(bpy-(CHO)2)]+ (complex 1) and [Ir(ppy)2(bpy-(COOH)2)]+ (complex 2), possessed two phenylpyridine ligands and a single R-bipyridine ligand. The formation of the encapsulated species (Q[10]·1 and Q[10]·2) was demonstrated by 1H NMR and luminescence studies. A significant improvement was observed in the luminescence properties of both iridium complexes (emission intensity, quantum yield and lifetime) upon the addition of Q[10] in an aqueous medium. Results suggested a major effect of the hydrophobic cavity in the destabilization of the 3MLCT state (lowest excited state) of the iridium complexes. The binding study of both complexes with Q[10] revealed the formation of 1 : 1 and 1 : 2 host–guest species, with the binary complex dominating the emission behavior. The equilibrium between the emitting species was significantly influenced by the temperature, wherein the 1 : 1 inclusion complex was less favorable at elevated temperatures. The effect of pH on the emission profiles of the free and encapsulated iridium complexes was also investigated in this study. Density functional theory (DFT) calculations showed that introducing different substituent groups (CHO and COOH) on the bpy ligand had a negligible effect on the orientation of these complexes within the Q[10] cavity.

Graphical abstract: Cucurbit[10]uril binding of heteroleptic iridium(iii) complexes: synthesis and photophysical characterization

Supplementary files

Article information

Article type
Paper
Submitted
15 May 2025
Accepted
04 Aug 2025
First published
20 Aug 2025
This article is Open Access
Creative Commons BY-NC license

RSC Adv., 2025,15, 29414-29423

Cucurbit[10]uril binding of heteroleptic iridium(III) complexes: synthesis and photophysical characterization

L. Alrawashdeh, S. Almarabeh, K. I. Assaf, A. I. Day, L. Wallace and S. A. Bani-Atta, RSC Adv., 2025, 15, 29414 DOI: 10.1039/D5RA03425F

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements