title: Ligand dependent self-assembly of hydroxido-bridged dicopper units templated by sodium ion.
abstract: Crown-ether like interaction of two neutral [Cu2(μ-OH)(μ-L(1))] (H3L(1) = 2-(2'-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) fragments, around a central Na(+) cation as self-assembly template, led to the formation of [Na{Cu2(μ-OH)(μ-L(1))}2]ClO4 (1). Di-tert-butyl group substituted H3L(2) {2-(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-bis[4-(3,5-di-tert-butyl-2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine} conversely yields only [Cu2(μ-OH)(μ-L(2))]·1.5H2O (2), by discarding aggregation around the Na(+) ion. The crown-ether type aggregate 1 exhibits ferromagnetic interactions within the double oxido-phenoxido [Cu2] fragments and weak antiferromagnetic interactions are mediated by the ONa(+)O bridges. Complex 2 registers only weak antiferromagnetic interactions within the oxido-phenoxido bridged [Cu2] entity. UV-visible and emission titration spectroscopy establish the interaction of cationic complex 1 with calf thymus DNA in Tris buffer and it cleaves supercoiled pBR322 DNA from in situ generated ROS.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India.
authors.forename: Avijit
authors.initials: A
authors.lastname: Sarkar
authors.forename: Alok Ranjan
authors.initials: AR
authors.lastname: Paital
authors.forename: Rais Ahmad
authors.initials: RA
authors.lastname: Khan
authors.forename: Farukh
authors.initials: F
authors.lastname: Arjmand
authors.forename: Valerio
authors.initials: V
authors.lastname: Bertolasi
authors.forename: Corine
authors.initials: C
authors.lastname: Mathonière
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Clérac
authors.forename: Debashis
authors.initials: D
authors.lastname: Ray
mesh_terms: D000818:Animals; D002417:Cattle; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D007477:Ions / Q000737:chemistry; D008024:Ligands; D008280:Magnetics; D008968:Molecular Conformation; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000737:chemistry; D012964:Sodium / Q000737:chemistry*; D013696:Temperature
chemical_list: D056831:Coordination Complexes; D007477:Ions; D008024:Ligands; D017382:Reactive Oxygen Species; D003300:Copper; D004247:DNA; C427203:calf thymus DNA; D012964:Sodium