Precursors of hexa-azamacrocycles. Synthesis and X-ray structure of 2,9-diaminophenanthroline-bisacetate-Co(II) and 6,6 '-diaminobipyridine-bisacetate-M(II) (M = Ni, Cu)

The synthesis, conventional characterisations and x-ray structures of the f ollowing monomeric complexes are given for 2,9-diaminophenanthroline-bisace tate-cobalt(II) ((A) under bar) and 6,6'-diaminobipyridine-bisacetate-M(II) (M = nickel((C) under bar) and copper((B) under bar)). Complex (A) under b ar crystalizes in the monoclinic, C2/c space group with a = 12.813(6), b = 10.218(3), c=13.811(5), Angstrom; beta = 118.17(2)degrees; Z = 4; V = 1549( 2) Angstrom (3). A total of 1787 unique reflections with F > 6 sigma (F) we re refined to values of R and R-w 0.0461 and 0.0774, respectively. Complex <(<beta>)under bar> crystallizes in the triclinic, P-1 space group with a = 10.099(5), b = 10.257(5), c = 8.015(11), Angstrom; alpha,= 112.98(2), beta = 93.13(2), gamma = 92.960(2),degrees; Z = 2; V = 761(1), Angstrom (3). A total of 2603 unique reflections with F > 3.00 sigma (F) were refined to va lues of R and R-w 0.0764 and 0.1022, respectively. Complex (C) under bar cr ystallizes in the monoclinic, P2(1)/n space group with a = 8.124(5), b = 10 .343(6), c = 18.724(11), beta = 98.36(2),degrees; Z = 4; V = 1556(1), Angst rom (3). A total of 2537 unique reflections with F > 3.00 sigma (F) were re fined to values of R and R-w 0.0689 and 0.0975, respectively. The structure s consist of six-coordinate [M(CH3COO)(2)(L)] (L = 2,9-diaminophenanthrolin e or 6,6'-diaminobipyridine) discrete monomeric neutral species, although i n the Cu(II) compound the elongation of two long Cu-O bonds, due to the Jah n-Teller effect, makes the metal essentially four-coordinate. In the Ni and Co compounds the acetate acts as a bidentate ligand. The diamino ligands a re coordinated by the pyridine nitrogen atoms. The IR spectra of the comple xes have been recorded and are discussed in relation to the crystal structu re and the acetate coordination mode.