Synthesis, supramolecular complexation and DFTstudies of a bis(pyrene)-appended ‘capped’ triazole-linked calix[4]arene as Zn²⁺ and Cd²⁺ fluorescent chemosensors

ABSTRACT

A new bimodal triazole-bridged pyrene-appended calix[4]arene 2g has been synthesised and characterised and complexation studies showed that the binding of Cd²⁺ and Zn²⁺ occurs as demonstrated by enhanced monomer and declining excimer emission fluorescence spectral changes. With several other metal ions, quenching of both monomer and excimer emissions occurred. The observed monomer formation in the fluorescence spectra seen with Zn²⁺ and Cd²⁺ is possibly linked not just to the diminished parallel orientations of the pyrene rings but with the magnitude of the resulting HOMO-LUMO gaps and other parameters measured by DFT calculations.

Graphical abstract

KEYWORDS:

• Calixarenes
• pyrene
• fluorescence spectroscopy
• supramolecular complexation
• DFT

Acknowledgments

PEG, SR and AA thank the Deanship of Scientific Research, King Saud University for funding of parts of this project through the Vice Deanship of Scientific Research Chairs. Dr. O. Stueker and Compute Canada are acknowledged for the ongoing support for the computational work. GJB and KSU thank NSERC (Canada) for on-going research financial support.

Disclosure statement

The authors declare no conflict of interest.

Supporting information

Experimental details and spectra of 2g, complexation and related DFT studies.

Supplementary material

Supplemental data for this article can be accessed here.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the NSERC (Canada) and the Deanship of Scientific Research, King Saud University.