Structural, electrochemical and spectroscopic characterization of a new [Cu2L2([mu-Cl)(2)](2)[CuCl4](2) dimer complex

Author(s)

Scarpellini, Marciela ; Neves, Ademir ; Castellano, Eduardo E. ^[3] ; Franco, Douglas W.

• Document type: Journal article
• Source: Journal of Molecular Structure; v. 694, n. 1-3, p. 193-198, Jun. 2004.
• Field of knowledge: Physical Sciences and Mathematics - Physics

Abstract

The bis{(mu(2)-chloro)[2-(imidazol-4-yl)ethyl][(1-methylimidazol-2-yl)methyl]amine}dicopper(II) bis[tetrachloro-cuprate (II)] complex [Cu-2(HISMIMA)(2)Cl-2](2)(CuCl4)(2) (HISMIMA:[(2-(imidazol-4-yl)ethyl)(1-methylimidazol-2-yl)methyl)amine]) was obtained by serendipity during the reaction of the mononuclear [Cu(HISMIMA)Cl-2] complex and gaseous nitric oxide in methanolic solution. The title complex unit cell has the composition: an anion complex {[Cu-2(HISMIMA)(2)Cl-2][CuCl4](2)}(2-) (1) and a cation complex [Cu-2(HISMIMA)(2)Cl-2](2+) (2). Cation 2 displays a crystallographic centrosymmetric Cu2Cl2 core with each Cull atom coordinated to the tripodal ligand in a square pyramidal geometry (Addison parameter tau = 0.07). In 1, a distorted octahedral geometry is observed, in which the Cu-II ions are coordinated in a way similar to that in 2 but with an additional interaction with the [CuCl4](2-) ions. Cyclic voltammetric experiments reveal that the title complex does not dissociate in acetonitrile solution and has E-1/2 = -0.24 V vs NHE (DeltaE(p) = 0.19 V, i(pa)/i(pc) = 0.75) for the (CuCuII)-Cu-II to (CuCuI)-Cu-I process at the Cu(mu-Cl)(2)Cu core. (AU)

• FAPESP's process: 99/07109-9 - Thermal and photochemical reactivity of ruthenium nitrosyl complexes: knowledge and control of the nitric oxide coordinated reactivity
• Grantee: Douglas Wagner Franco
• Support Opportunities: Research Projects - Thematic Grants