SYNTHESIS, CHARACTERIZATION AND CRYSTAL-STRUCTURES OF BISMUTH(III) COMPLEXES WITH TRIETHYLENETETRAAMINEHEXAACETIC ACID AND TRANS-CYCLOHEXANE-1,2-DIAMINETETRAACETIC ACID

Two new water-soluble bismuth(III) complexes with polyaminocarboxylate ligands have been prepared, characterized by IR spectroscopy and crys tal-structure analysis. The complex with triethylenetetraaminehexaacet ic acid (H(6)ttha) has the stoichiometry Bi(H(3)ttha). 3H(2)O 1. It cr ystallizes in the space group P2/c with two independent 1/2 (H(3)ttha . Bi) units in which the cations are located on the crystallographic t wo-fold axis. It is the first example of a polyaminocarboxylate comple x of Bi-III displaying a co-ordination number of ten, through four nit rogen atoms and six oxygens belonging to the acetates. The ligand is w rapped round the cation in a bicapped square-antiprismatic geometry. I n the complex with trans-cyclohexane-1,2-diaminetetraacetic acid (H(4) cydta), Bi(Hcydta). 5H(2)O 2, the co-ordination number is eight with a square-antiprismatic geometry around the Bi. For each Bi atom two of the co-ordinated oxygen atoms belong to neighbouring molecules; these bridging oxygen atoms are different in the two subunits and connect th e complexed entities in a polymeric network.