ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Identification of a novel click-derived 1,2,3-triazole as selective Hg²⁺ ion detector: computational and experimental investigations

Rabail Ujan, Nasima Arshad, Fouzia Perveen, Pervaiz Ali Channar, Bhajan Lal, Mumtaz Hussain, Zahid Hussain, Aamer Saeed, and Syeda Aaliya Shehzadi

M. A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, Pakistan

E-mail: nasimaa2006@yahoo.com

Received: 26 April 2021  Accepted: 26 July 2021

Abstract:

A new triazole-substituted compound (7), namely {5-((2-methyl-4-(3-methyl-4-(prop-2-ynyloxy) benzyl) phenoxy) methyl)-1-(3-(nitrophenoxy) propyl)-1h-1, 2, 3-triazole}, was synthesized through the coupling of azido and propargylated precursors via click approach using 1,3-dipolar cycloaddition reaction. This compound was further explored for its selectivity and sensitivity toward mercury (Hg²⁺) ions detection. Quantum chemical DFT calculations were performed to examine the adsorption of Hg(OOCCH₃)₂ on the surface of compound 7. The charge distributions before and after adsorption showed charge transfer from 7 to Hg(OOCCH₃)₂ which indicated that 7 was sensitive to Hg(OOCCH₃)₂ molecule for Hg⁺² detection. The lowing in energy gap (ΔE), higher electrical conductivity and increased density of states (DOS) after Hg(OOCCH₃)₂ adsorption further depicted the potential of 7 as a chemical sensor for Hg⁺² sensing. The photophysical potential of compound (7) was examined by employing a range of cations (Ba²⁺, Ca²⁺, Co²⁺, Hg²⁺, K⁺, Mg²⁺, Mn²⁺, Na⁺, NH⁴⁺ and Pd²⁺). A significant hyperchromic shift in compound 7 spectrum (UV/ and fluorescence) upon equimolar addition of Hg²⁺ ions indicated that the triazole-based compound (7) has exhibited selective interaction with Hg²⁺ ion in preference to other cations. The maximum chelation of compound (7) with Hg²⁺ was observed at pH 5.1 (slightly acidic medium). The compound (7) capability to recognize Hg²⁺ was observed even at 0.1 µM detectable limit, indicating greater sensitivity of 7 toward Hg²⁺. No significant effect of competitive metal ions on 7 – Hg²⁺ complex further authenticated robust selectivity and sensitivity of 7 toward sensing Hg²⁺ions. Binding mechanism indicated the formation of 2:1 complex of 7 - Hg²⁺. DFT and spectral findings complimented each other and proving the promising chemosensor candidacy of the compound 7 for Hg²⁺ ions.

Graphic abstract

Keywords: Click-derived 1,2,3-triazole; Chemosensor; Selective Hg2+ detection; Computational DFT studies; Spectroscopic studies

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01804-7

Chemical Papers 75 (12) 6377–6388 (2021)