99748-36-4Relevant articles and documents
Copper complexes of a flexible binucleating ligand. Syntheses and spectroscopic, thermodynamic, and kinetic studies
Youinou, Marie-Thérèse,Osborn, John A.,Collin, Jean-Paul,Lagrange, Philippe
, p. 453 - 461 (2008/10/08)
The synthesis of the macrocyclic "earmuff" ligand 1,4-bis((1-oxa-4,10-dithia-7-azacyclododec-7-yl)methyl)benzene, L, and its mononucleating analogue L′ is reported. L and L′ react with copper(I) to form the dinuclear and mononuclear complexes [Cu2L]X2, [Cu2L′3]X2, and [CuL′]X (X = BF4, ClO4, PF6, OTf). Binding of the donor groups has been investigated by NMR spectroscopy in a donor solvent (acetonitrile, dimethyl sulfoxide). The accessibility of the copper(II) centers to reaction is demonstrated by the formation of a stable bis(triphenylphosphine) adduct [Cu2L(PPh3)2]X2 as well as the reversible addition of carbon monoxide in propylene carbonate to [Cu2L]X2. The synthesis of the binuclear copper(II) complexes [Cu2L]X4 and [Cu2(μ-OH)L]X3 and of the mononuclear species [CuL′]X2 as well as their characterization by spectroscopic methods is also reported. Finally the complexation of Cu(II) by L and L′ has been investigated by potentiometric and spectrophotometric means. Our results show the very high stability in water of [Cu2(μ-OH)L]3+, which can be rapidly protonated under the appropriate conditions to form [Cu2L]4+, thereby demonstrating the conformational flexibility of L.
