Characterisation and structure of two Cu(II) mononuclear compounds with 7-azaindole as a ligand that display interesting H-bond properties

Two Cu(II) compounds with the ligand 7-azaindole (abbreviated as Haza) have been synthesized and fully characterized by spectroscopy, EPR and X-ray structure analysis. The first compound, Cu2Cl4(Haza)6 (1), consists of two different Cu(II) sites, i.e. [Cu(Haza)2Cl3]+ and [Cu(Haza)3Cl]−, both with a distorted square-pyramidal geometry for the Cu(II) ion. A hydrogen bond network exists between N-Cl atoms in each unit and also between the two units. The second compound, [Cu(Haza)4F](BF4)(H2O) (2), in which the fluoride anion is generated from decomposition of BF4− anions, has also a distorted square-pyramidal geometry. The structure is stabilized by hydrogen bonds between the N-H groups and the F ions. The water is at a disordered lattice position. Further characterization has been performed using IR, LF and EPR spectroscopy.