Issue 24, 2011

Selective colorimetric and fluorometric sensing of Cu(ii) by iminocoumarin derivative in aqueous buffer

Abstract

A new iminocoumarin based receptor L (C27H26N4OS) is synthesized with pyridyl and benzothiazolyl functionality. Synthesis of L is easy and it is isolated in good yield. L shows a selective and distinct color change from yellow to orange with Cu2+ over Li+, Na+, Ca2+, Mg2+, Cr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, and Ag+ whereas a slight change in color is also observed in the case of Hg2+ but L shows selective fluorescent quenching only in the presence of Cu2+ in aqueous HEPES buffer (pH 7.0). The naked eye detection limit of Cu2+ is determined at 2 μM whereas an emission experiment shows a lower detection limit at 200 nM. Selectivity studies of L in presence of 50 equivalents of other ion(s) by emission experiment show no interference toward the detection of 1 equivalent of Cu2+. Both UV-Vis and fluorescence studies in the presence of Cu2+-salts of different counter anions with various sizes and shapes (Cl, ClO4, NO3, CF3SO3, SO42 and BF4) show almost similar spectral output in buffer media irrespective of the nature of the counter anions. The detailed UV-Vis and fluorescence titration experiments suggest the existence of both 1 : 1 and 2 : 1 (L : Cu2+) complexation stoichiometry and EPR study shows dx2y2 ground state of the Cu(II) centre in the complex. Furthermore the formation of a mononuclear [Cu(L)(CH3CN)].2ClO4 complex and the flexible conformation of L in the solid state are confirmed by the single-crystal X-ray structural study.

Graphical abstract: Selective colorimetric and fluorometric sensing of Cu(ii) by iminocoumarin derivative in aqueous buffer

Supplementary files

Article information

Article type
Paper
Submitted
01 Feb 2011
Accepted
07 Apr 2011
First published
16 May 2011

Dalton Trans., 2011,40, 6411-6419

Selective colorimetric and fluorometric sensing of Cu(II) by iminocoumarin derivative in aqueous buffer

B. N. Ahamed and P. Ghosh, Dalton Trans., 2011, 40, 6411 DOI: 10.1039/C1DT10177C

To request permission to reproduce material from this article, 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 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