Coordination studies of 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine towards Zn2+ cation.: Synthesis and characterization by X-ray diffraction and spectroscopic methods

The two Zn(II) complexes Zn(dppt)Cl(2)(.)0.5 H2O (1) and Zii(dppt)(2)Cl(2)(.)2 H2O (2) were obtained by reaction of 5,6-diphenyl3-(2-pyridyl)- 1,2,4-triazine (dppt) with zinc chloride. Complex (2) could be obtained from (1) by addition of an excess of dppt. These complexes have been characterized by ID and 2D H-1 NMR spectroscopy, mass spectrometry, and in the solid state by IR and X-ray diffraction. In (1), the Zinc atom is bound to one ligand through the N atom of the pyridyl ring and one of the N atoms of the triazine ring, and to two chlorine atoms in a distorted tetrahedral coordination geometry. Instability of crystals of compound (2) (namely, the lost of crystallization solvent molecules) did not allow their analysis by X-ray diffraction. Structure and stoichiometry of (2) were determined by 2D COSY H-1 NMR and mass spectrometry. Two magnetically equivalent ligands (dppt) are coordinated to the metal center. (c) 2005 Academie des sciences. Published by Elsevier SAS. All rights reserved.