A combined experimental and theoretical investigation on the Cu(II) sensing behavior of a piperazinyl moiety based ligand, and catecholase and biological activities of its Cu(II) complex in combination with pyridine 2,5-dicarboxylate

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• 作者：Soumen Mistri^a ; Aparup Paul^a ; Apurba Bhunia^a ; Rajesh Kumar Manne^b ; Manas Kumar Santra^b ; Horst Puschmann^c ; Subal Chandra Manna^a ; ^{scmanna@mail.vidyasagar.ac.in" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Copper(II) ; Electronic spectra ; DFT ; Fluorescence sensor ; Catecholase activity
• 刊名：Polyhedron
• 出版年：2016
• 出版时间：28 January 2016
• 年：2016
• 卷：104
• 期：Complete
• 页码：63-72
• 全文大小：2479 K

文摘

A Cu(II) fluorescent chemosensor, 6-methoxy-2-{[2-(1-piperazinyl)ethylimino]methyl}phenol (HL), has been synthesized and characterized by FT-IR, NMR, electronic absorption and emission spectral studies. HL shows high selectivity for Cu(II) over a range of other metal ions. HL has a 24.87 μM (R² = 0.9959) fluorometric detection limit for Cu(II), which is very close to the maximum allowable level of Cu(II) in drinking water as recommended by US EPA. Theoretical calculations at the B3LYP level revealed that the formation of a five-coordinated complex in solution is responsible for the observed sensing behavior. The binding constant for the 1:1 complex between Cu(II) and HL was determined using fluorescence titration, and the calculated value is 0.4 liter/mol. Using HL, {[Cu(HL)(pdc)(H₂O)]·[Cu(HL)(pdc)]·10.5(H₂O)} (1) (pdc = pyridine 2,5-dicarboxylate) has been synthesized and structurally characterized. Complex 1 is active for catalyzing aerobic oxidation of 3,5-di-tert butyl catechol (3,5-DTBC) to 3,5-di-tert butyl benzoquinone (3,5-DTBQ). Anticancer activity of 1 in human breast (MCF7) cancer cell lines reveals dose dependent suppression of cell viability with IC₅₀ value 47 ± 5.2 μM.