NEW SYNTHESIS OF BIS(3,3'-DIMETHYL-2,2'-DIPYRIDYLAMINE)COPPER(II) AND THE CRYSTAL-STRUCTURE OF THE COMPLEX

The copper(II) complex (1) of the deprotonated form of 3, 3ʹ-dimethyl-2, 2ʹ-dipyridylamine has been prepared by reacting the ligand with freshly prepared copper(II) hydroxide. The crystal and molecular structure have been determined. Crystal data: space group P212121 Z = 4, a = 8.639 (1) Å, b= 14.358 (4) Å, c = 17.510 (3) Å, V = 2172 Å 3, R = 3.9% for 1875 reflections. The copper environment is pseudotetrahedral, with a dihedral angle of 57.4° between the two CuN2 ligand planes. This accurate structure provides a new and somewhat better calibrant for the correlation between the spectra and structures of pseudotetrahedral copper(II) complexes than the known [Cu(HDPA)2](ClO4)2 complex (2) (R = 9.4%), where HDPA = 2, 2ʹ-dipyridylamine. The differences between complexes 1 and 2 include a slightly closer approach to tetrahedral configuration of copper(II) in complex 1 and far greater deviation of the ligands from planarity in 2, as well as a major displacement of the metal atom from one of the ligand planes. Although the difference between the dihedral angles in the two complexes is small (57.4 and 55.6°), the trend is in the right direction when compared to spectral assignments. © 1979, American Chemical Society. All rights reserved.