The Crystal and Molecular Structures of 2,5-Bis(2'-pyridyl)-pyrazine (BPPZ) and Some 3d Transition-Metal Complexes

Abstract

The symmetrical ligand 2,5-bis(2'-pyridyl)pyrazine (BPPZ) exists in the extended form with a dihedral angle between the pyrazine and the pyridine rings of 7.88°. BPPZ forms symmetrical bis(bidenate) complexes with Mn^II, Fe^II, and Cu^II. The dihedral angles between the best planes through the planar pyrazine ring and the pyridine ring are 2.6° in the Mn^II complex, 4° in the Fe^II complex, and 8.5° in the Cu^II complex. The metal-N_py bond distances are shorter than standard values and similar in length to the metal-N_pz distances.