SYNTHESIS AND SPECTROSCOPIC PROPERTIES OF N-ACETYL-DL-PHENYL-GLYCINATO COMPLEXES OF COBALT(II), NICKEL(II) AND COPPER(II) - CRYSTAL-STRUCTURES OF GLYCINATO)DIAQUOBIS-(N-METHYLIMIDAZOLE)COBALT(II), -DL-PHENYLGLYCINATO)DIAQUOBIS(IMIDAZOLE)COBALT(II) AND NICKEL(II)

A series of complexes of N-acetyl-DL-phenylglycine and Co-II, Ni-II an d Cu-II containing heterocyclic bases as imidazoles, phen, bipy and te rpy were prepared and characterized by conventional methods, IR spectr a and, for [Co(OH2)(2)(mimi)(2)(Ac-phgly)(2)] (1), [Co(OH2)(2)(imi)(2) (Ac-phgly)(2)] (2) and [Ni((OH2)(2)(imi)(2)(Ac-phgly)(2) (3), by X-ray crystal structure. The structure of these complexes consists of discr ete [M(OH2)(2)(mimi/imi)(2)(Ac-phgly)(2)] units in which the metal sho ws nearly ideal centrosymmetrical trans-octahedral geometry bonding tw o imidazole nitrogens, two carboxylic oxygens and two water molecules. In all cases the amino acid behaves as monodentate via carboxylic oxy gen, the second carboxylic oxygen; the NH and CO peptide groups are in volved in hydrogen bonds which are responsible for the packing in the crystal.