artículo con referato
"Spectroscopic Evidence in Solid and Solution of a Discrete Copper (I) Tetrahedral Complex Dimer Supported by Supramolecular Interactions"
D.H. Jara, L. Lemus, L. Farías, E. Freire, R. Baggio and J. Guerrero
Eur. J. Inorg. Chem. 2012(10) (2012) 1579-1583
Abstract
The first study of the self-association of a copper(I) tetrahedral complex ([Cu(N-{4-nitrophenyl}pyridine-2-yl-methanimine)(PPh3)Br]) has been performed. The formation of a discrete dimer supported by supramolecular π–π stacking and C–H⋯Br interactions was established by X-ray diffraction techniques. 1D- and 2D NMR techniques were used for the structural characterization of this compound in solution. Unexpected 1H-1H NOE effects are coherent with the presence of a dimer in solution, whose structure replicates that found in the crystal. Dimerization constants obtained by VT-1H NMR spectroscopy allowed the determination ofthe thermodynamic parameters for the self-association process, namely ΔS = -0.67±0.21 cal mol-1K-1, ΔH = -2.00±0.05 kcal mol-1 and ΔG(298 K) = -1.79 kcal mol-1. Consequently, this association process is enthalpy driven.
DEPARTAMENTO FISICA DE LA MATERIA CONDENSADA