SYNTHESES AND STRUCTURES OF BISMUTH(III) COMPLEXES WITH NITRILOTRIACETIC ACID, ETHYLENEDIAMINETETRAACETIC ACID, AND DIETHYLENETRIAMINEPENTAACETIC ACID

The reactions of bismuth subcarbonate with nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and diethylenetriaminepentaacetic acid (DTPA) were used to synthesize the respective bismuth complexes: (nitrilotriacetato)bismuth(III) dihydrate (1), (hydrogen ethylenediaminetetraacetato)bismuth(III) dihydrate (2), and bis(guanidinium) (diethylenetriaminepentaacetato)bismuthate(III) tetrahydrate (3). The structures of all three complexes were determined by single-crystal X-ray studies. In 1 the ligand is completely deprotonated, so that the resulting complex is neutral. The bismuth is eight-coordinate, the coordination sphere being completed by two water molecules and the 02 and 03' oxygens from an adjacent BI(NTA) molecule. The best description appears to be that of a bicapped trigonal prism. In the Bi(HEDTA) complex, 2, the ligand is singly protonated to give 3-charge. The EDTA ligand coordinates in a hexadentate fashion involving the two nitrogen atoms and four of the carboxylate oxygen atoms of the EDTA ligand. The Bi atom is eight-coordinate in a bicapped trigonal prism arrangement. There are no coordinated water molecules. The Bi(DTPA) complex, 3, was isolated as the guanidinium(l+) salt. In 3 the Bi atom is nine-coordinated with a monocapped square antiprism arrangement, using the three nitrogens and five oxygen atoms from the DTPA ligand and one 0 from an adjacent molecule. There are no coordinated water molecules. The BI(DTPA) is the most soluble of the three complexes. Valence bond sums were calculated and are given for all three complexes. The antibacterial activities of the three complexes 1-3 were determined, and the least soluble complex, 1, was found to be the most active. Crystallographic data: 1, C6H6NO6Bi.2H(2)O, monoclinic, P2(1)/n,a=6.242(1)Angstrom,b=20.927(3)Angstrom,c=8.307(1)Angstrom,beta=102.49(1)degrees,Z=4;2,C10H13N2O8Bi.2H(2)O, monoclinic, Cc,a=17.196(2)Angstrom,b=6.837(1)Angstrom,c=13.277(2)Angstrom,beta=105.74(1)degrees,Z=4;3,C16H30N9O10Bi.4H(2)O, monoclinic,P2(1)/n,a=15.113(3)Angstrom,b=10.720(2)Angstrom,c=17.091(3)Angstrom,beta=102.72(2)degrees,Z=4.