Spectroscopic Evidence in Solid and Solution of a Discrete Copper(I) Tetrahedral Complex Dimer Supported by Supramolecular Interactions

DANILO JARA; LUIS LEMUS; LILIANA FARÍAS; ELEONORA FREIRE; RICARDO BAGGIO; JUAN GUERRERO

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2012 p. 1579 - 1583

1434-1948

The first study of the self-association of a copper(I) tetrahedralcomplex ([Cu(N-{4-nitrophenyl}pyridine-2-yl-methanimine)(PPh3)Br]) has been performed. The formation of adiscrete dimer supported by supramolecular π–π stackingand C–H···Br interactions was established by X-ray diffractiontechniques. 1D- and 2D NMR techniques were used forthe 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 thatfound in the crystal. Dimerization constants obtained by VT-1H NMR spectroscopy allowed the determination ofthe thermodynamic parameters for the self-association process,namely ΔS = –0.670.21 calmol–1K–1, ΔH =–2.000.05 kcalmol–1 and ΔG(298 K) = –1.79 kcalmol–1.Consequently, this association process is enthalpy driven.-