Reaction of 2picolylmethylamine with CuBrz in water in an open vessel gives, together with other products, green crystals of the title compound
, the structure of which has been determined by a threedimensional X-ray structural analysis. Crystals were monoclinic with a = 8.38(l), b = 27.60(3), c = 7.69(l) A, and 0 = 114.6(l)", space group P2,/c and Z = 4. The structure was solved by conventional Patterson and Fourier techniques, and was refined aniso tropically by least-squares methods, using 1098 unique reflections to a final R of 0.070. Data were obtained
photographically, with intensities determined on an integrating microdensitometer. The analysis shows each copper atom to be five-coordinate [Cu(NJBrJ , intermediate in structure between the square pyramidal and trigonal bipyramidal extremes. The metal is bonded to a terdentate ligand which is an unusual carbinolamine formed by the condensation of one mol of 2-picolylmethylamine with a mol of pyridine-2-aldehyde, formed by oxidative de-amination of the amine. Bond lengths in the co-ordination polyhedron are: CL-Br(l) 2..598(3), CL-Br(2) 2.436(3), Cu-N(pyridy1) 1.98(l) (au), and Cu-N (tertiary amine) 2.07(l) A. The water molecule is hydrogen-bonded to the alcohol group of the [N3] ligand, and joins adjacent molecules through H-bonds to their Br(1) s.