CHLOROMERCURATES OF TWO AMINECARBOXYLATE COBALT(III) COMPLEXES. Kerry D. Robinson and Izya F. Burshtein, Siemens Energy and Automation, Inc., 6300 Enterprise Ln., Madison, WI 53719-1173, USA, Anatolii L. Poznyak, Institute of Molecular and Atomic Physics, 220072, Minsk, Belarus

For the first time , compounds of two cobalt(III) complexes, C¹ and C² are synthesized (C¹=[Co(en)L¹]²⁺, C²=[Co(dien)L²]²⁺, L¹ and L² N,N-bis(2-aminoethyl) amino-3-propionate or S-ornithinate ions respectively). L¹ anions were prepared by the Hofmann destruction of corresponding amide, N,N-bis(2-carbamoylethyl)amino-3-propionate, prepared, in its turn, from b-alanine and acrylamide.

The crystal and molecular structures of the C² perchlorate, [C²] (ClO₄)₂. 1/2H₂O, and chloromercurates of both cations characterized by general formulae [C]HgCl₄ and [C]Hg₂Cl₆ are determined by x-ray analysis. Chloromercurates of both types are deposited simultaneously from solutions of the corresponding perchlorates or chloride after addition of mercuric chloride in excess.

Both cations are low-spin octahedral cobalt(III) complexes of the Co(N)₅(O) type of the C¹ cations, three N atoms of the L¹ ligand are arranged facially, whereas in the C² cations middle N atom of the dien ligand lies in trans position to N atom of the ornithinate side chain.

The crystals of [C]HgCl₄ compounds contain discrete tetrahedral tetracloromercurate(II) anions. Anionic parts of [C]Hg₂Cl₆ crystals are built of a variety of species. In some of them, there is interaction of Hg atoms with carboxylate O atoms of the complex cations. Three Hg-containing species are found in [C¹]Hg₂Cl₆ crystals: a) HgCl₃ anions coupled to O atom (tetrahedral HgCl₃O species); b) Cl₃Hg(m-Cl)HgCl₂ dimers; c) centrosymmetric Cl₂Hg(m-Cl)₂HgCl₂ dimers. The [C²]Hg₂Cl₆ crystals contain two crystallographically unequivalent HgCl₃ and HgCl₃O ions as well as Cl₃Hg(m-Cl)HgCl₂O dimers.