Ligand dependent self-assembly of hydroxido-bridged dicopper units templated by sodium ion

Avijit Sarkar (1) , Alok Ranjan Paital (1) , Rais Ahmad Khan (2) , Farukh Arjmand (2) , Valerio Bertolasi (3) , Corine Mathonière (4) , Rodolphe Clérac (5) , Debashis Ray (1)

1 Department of Chemistry, Indian Institute of Technology
2 Department of Chemistry, Aligarh Muslim University
3 Dipartemento di Science Chimiche e Farmaceutiche
4 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
5 CRPP - Centre de recherches Paul Pascal

Crown-ether like interaction of two neutral [Cu2(μ-OH)(μ-L1)] (H3L1 = 2-(2'-hydroxyphenyl)-1,3-bis[4- (2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) fragments, around a centralNa+ cation as self-assembly template, led to the formation of [Na{Cu2(μ-OH)(μ-L1)}2]ClO4 (1). Di-tert-butyl group substituted H3L2 {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-L2)]*1.5H2O (2), by discarding aggregation around the Na+ ion. The crown-ether type aggregate 1 exhibits ferromagnetic interactions within the double oxidophenoxido [Cu2] fragments and weak antiferromagnetic interactions are mediated by the O⋯Na+⋯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.

Mots clés: Ligand; Antiferromagnetic interactions

Domaines: Matériaux

Avijit Sarkar, Alok Ranjan Paital, Rais Ahmad Khan, Farukh Arjmand, Valerio Bertolasi, et al.. Ligand dependent self-assembly of hydroxido-bridged dicopper units templated by sodium ion. Dalton Transactions, 2013, 42, pp. 12495-12506. ⟨10.1039/c3dt51095f⟩. ⟨hal-00856636⟩