1‐(2‐Pyridyl)‐3‐ferrocenylpyrazoline‐Based Multichannel Signaling Receptors for Co2+, Cu2+, and Zn2+ Ions. Issue 35 (29th October 2013)

• Record Type: Journal Article
• Authors: Kumar, Chakka Kiran; Trivedi, Rajiv; Kumar, Kanaparthi Ravi; Giribabu, Lingamallu; Sridhar, Balasubramanian
• Is Part Of: European journal of inorganic chemistry. Issue 35(2013)
• Page Start: 6019
• Page End: 6027
• Publication Date: 2013-10-29
• Subjects: Ferrocene -- Pyridylpyrazoline -- Sensors -- Fluorescence -- Electrochemistry; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201300944
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: A simple one‐pot synthesis, the characterization, optoelectronic, and cation sensing properties of 1‐(2‐pyridyl)‐3‐ferrocenylpyrazolines4 –6 are described in this article. Reaction of ferrocenyl chalcones with 2‐hydrazinopyridine gave the target compounds in good yield. These compounds were characterized by general spectroscopic techniques and the structure of4 was determined by means of X‐ray crystallography. These ferrocene compounds behave as selective multichannel chemosensors (redox, chromogenic, and fluorescent) in the presence of Co 2+, Cu 2+, and Zn 2+ ions. The binding assay and recognition ability of these receptors towards the metal ions were explained by electrochemical and optical studies. A maximum cathodic shift in the redox potential of the ferrocenium couple was observed towards the Co 2+ ion (Δ E 1/2 = 99–156 mV), while a minimum shift was observed with the Zn 2+ ion (Δ E 1/2 = 72–129 mV) on complexation with these receptors. Disappearance of the high‐energy (HE) band and a red shift (Δ λ = 7–13 nm) of the low‐energy (LE) band in the absorption spectra of the receptors4 and5 was observed upon complexation with these metal ions. This change in absorption was accompanied by a color change from yellow to red/brown, which enabled potential "naked eye" detection. The emission spectra ( λ ex = 350 nm) of receptor4, in the presence of these cations, showed a 2–7‐fold increment in the chelation‐enhancement fluorescence (CHEF) and a 4–9‐fold increase in the quantum yield. Abstract : A series of three 2‐pyridylpyrazoline‐based ferrocene derivatives were prepared by a one‐pot method and these receptors behaved as selective multi‐channel sensors towards Co 2+, Cu 2+, and Zn 2+ ions. The recognition ability and binding assay for these receptors towards these metal ions were explained by redox (DPV) and optical (absorption and emission) studies.