Complexes of bismuth(III) with aminopolycarboxylic acids. Crystal structures of guanidinium aqua(ethylenediamineteraacetato)bismuthate(III) and aminoguanidinium ethylenediaminetetraacetatobismuthate(III)

In the crystal structure of guaninidium aqua(ethylenediaminetetraacetato)bi smuthate(III), the ethylenediaminetetraacetato tetraanion chelates to the b ismuth atom through its two amino and four carboxyl oxygen atoms. A carboxy late bridge [Bi-O = 2.694(4) Angstrom] links adjacent water-coordinated [Bi -O-water = 2.673(4) Angstrom] ethylenediaminetetraacetatobismuthate(III) an ions into a helical linear chain. The bismuth atom is eight-coordinate in a square-antiprismatic environment. The bismuth atom shows dodecahedral coor dination in aminoguanidinium ethylenediaminetetraacetatobismuthate(III). Th e crystal structure features a short carboxyl bridge [Bi-O = 2.657(4) A] th at links the bismuthate anions into a dinuclear entity; adjacent entities a re linked by a long carbonyl bridge [Bi-O = 2.931(4) Angstrom] into a linea r chain. In both ethylenediaminetetraacetatobismuthates(III), the lone-pair of electrons is stereochemically inert.