abstract
Variation of pyridyl based receptors around a Cu(II) center results in structural diversity allowing redox triggered Cu(II)/Cu(I) fluorescence switch for intracellular Cu(I) imaging. Single crystal X-ray structures of 2-hydroxy-6-methylnicotinic acid (L1), its mono nuclear Cu(II) complex, viz. [Cu(L1)(2)(H2O)(SO4)]center dot 2H(2)O (C1a), polymeric Cu(II) complex (C1b) and a dinuclear Cu(II) complex of 2-(naphthalen-2-ylmethylsulfanyl)nicotinic acid (L4), viz. [Cu-2(L4)(4)(H2O)(2)]center dot 1.12H(2)O (C4) with a Cu-Cu distance of 2.6028(7) angstrom are reported. Moreover, C1a interacts with calf thymus DNA, which is useful for disruption of normal DNA activity with plausible applications in biology (binding constant, K' = 1.56 x 10(4)). Chemical or electrochemical reduction of C1a generates a fluorescent Cu(I) complex. The lowest detection limit of L1 for Cu(I) is 50 mu M. The association constant of L1 for Cu+ is 7.09 x 10(2). Quenching constants of Cu(II) for L1, L2, L3 and L4 are 4 x 10(5), 4.2 x 10(6), 8.9 x 10(5) and 4.4 x 10(6), respectively. The magnetic behavior of C1b indicates a ferromagnetic one-dimensional solid.
keywords
CALF THYMUS DNA; PI-PI STACKING; CRYSTAL-STRUCTURE; COORDINATION POLYMERS; WILSON-DISEASE; COPPER; SENSOR; CELLS; CU+; ENHANCEMENT
subject category
Chemistry
authors
Adhlkari, S; Sahana, A; Kumari, B; Ganguly, D; Das, S; Banerjee, PP; Banerjee, G; Chattopadhyay, A; Fondo, M; Matalobos, JS; Brandao, P; Felix, V; Das, D
our authors
Paula Cristina Ferreira da Silva Brandão
Assistant Researcher
Vítor Félix
Associate Professor with Aggregationacknowledgements
Authors sincerely acknowledge CAS II (BU) and Sandip Mandal (BU) for assistance. DB is grateful to the UGC, New Delhi for fellowship under UGC Major Research Project [39-749/2010(SR)] to SD. DD and SD are grateful to DST, Govt. of India, New Delhi for a special grant to the Department of Chemistry, Jadavpur University in 2011 on the occasion of