Jump to main content
Jump to site search


Effect of charge transfer and structural rigidity on divergent luminescence response of a metal organic framework towards different metal ions: luminescence lifetime decay experiments and DFT calculations

Author affiliations

Abstract

We have thoroughly studied the luminescence behaviour of a cadmium based MOF, [Cd(C12N2H8)(C7N1O4H3)] {C12N2H8 = 1,10-phenanthroline, C7N1O4H3 = 2,5-pyridine dicarboxylate}, 1. Both steady-state and time-resolved luminescence spectroscopic experiments were performed to understand the dissimilar responses of compound 1 towards different metal ions in aqueous medium. Upon excitation at 280 nm, compound 1 showed a luminescence spectrum centered at 365 nm, which exhibited a three-fold turn-on in the presence of a trace amount of Zn2+ in aqueous solution, whereas in the presence of Co2+, Hg2+, Ni2+, Fe2+ and Cu2+ the luminescence of compound 1 got largely quenched. Compound 1 did not show any response in the presence of other common metal ions such as K+, Mg2+, Na+, Mn2+, and Cr3+. By analysing all the experimental results, we successfully explained the versatile luminescence behaviour of compound 1. The turn-on of luminescence in the presence of Zn2+ ions was due to coordination bond formation and enhancement of the rigidity of compound 1 which resulted in the reduction of non-radiative decay processes to a large extent. The quenching of luminescence in the presence of transition metal ions was found to be static in nature, and was due to the possibility of ligand to metal charge transfer using the vacant d-orbital of the metal ions. In the case of Hg2+ which is a closed cell heavy metal ion, the quenching of luminescence was also static in nature and was due to a two-way charge transfer mechanism. We have also performed density functional theory calculations and obtained supportive results for the proposed mechanisms of luminescence turn-on and quenching. Moreover, compound 1 could be established as a selective and efficient sensor of Zn2+ in aqueous solution even in the presence of Cd2+ and other metal ions.

Graphical abstract: Effect of charge transfer and structural rigidity on divergent luminescence response of a metal organic framework towards different metal ions: luminescence lifetime decay experiments and DFT calculations

Back to tab navigation

Supplementary files

Publication details

The article was received on 15 Jan 2019, accepted on 28 Jan 2019 and first published on 29 Jan 2019


Article type: Paper
DOI: 10.1039/C9PP00024K
Citation: Photochem. Photobiol. Sci., 2019, Advance Article

  •   Request permissions

    Effect of charge transfer and structural rigidity on divergent luminescence response of a metal organic framework towards different metal ions: luminescence lifetime decay experiments and DFT calculations

    P. Majee, D. K. Singha, S. K. Mondal and P. Mahata, Photochem. Photobiol. Sci., 2019, Advance Article , DOI: 10.1039/C9PP00024K

Search articles by author

Spotlight

Advertisements