PREPARATION AND X-RAY CRYSTAL-STRUCTURES OF LI-4[HG-2(EDTA)(2)]CENTER-DOT-8H(2)O AND BA-2[HG-2(TETA)(2)]CENTER-DOT-9H(2)O (TETA = N,N,N',N'-DIAMINOBUTANETETRAACETATE)

The Hg(II) complexes of the N,N,N',N'-tetraacetate of 1,2-diaminoethan e (edta) and 1,4-diaminobutane (teta) were crystallized from concentra ted aqueous solutions. The first ligand gave crystals of Li-4[Hg-2(edt a)(2)]. 8H(2)O. Its single crystal X-ray structure determination (tric linic space group P (1) over bar with a = 9.369(3), b = 9.354(3), c = 11.584(4) Angstrom, alpha = 67.90(2), beta = 67.50(2), gamma = 80.42(3 )degrees and Z = 1) showed that each mercury(II) is mainly bound to si x donor atoms of the same ligand anion. The coordinated anionic ligand is strained and leaves sufficient space for a seventh donor atom, i.e . a coordinated oxygen atom of the nearest complex ion bound with a mu ch shorter Hg-O distance. The second ligand gave Ba-2[Hg-2(teta)(2)]. 9H(2)O (space group C2/c with a = 17.840(2), b = 15.243(2), c = 18.962 (6), beta = 113.84(1)degrees and Z = 4) containing two equivalent liga nd anions giving the simplest polymeric structure, i.e. a dimer. These results are in agreement with the data obtained from equilibrium stud ies. (C) 1998 Elsevier Science S.A. All rights reserved.