CRYSTAL-STRUCTURE OF HEXA(3,5-DICARBOXYPYRIDINE)POTASSIUM TETRABROMOAURATE(III)

The title complex has been prepared, and characterized by X-ray crystallography. The crystals are rhombohedral, space group R32, with a=20.954(5), c=9.753(1) Å, Z=3, and RF=0.070 for 680 observed Mo Kα reflections. The structure consists of a packing of hexa(3,5-dicarboxypyridine) potassium cations and tetrabromoaurate(III) anions. The potassium atom is surrounded by equivalent oxygen atoms to form a KO6 octahedron with a very short K-O distance of 2.56(1) Å. The AuBr4- group exhibits orientational disorder with a mean bond length of 2.38(1) Å. Two symmetric strong hydrogen bonds (linear O⋯H⋯O and bent N⋯H⋯N) are found in the crystal structure. The nearly planar organic ligands are interlinked by hydrogen bonds to form parallel sheets which approximately correspond to the (003) family of planes. The potassium atoms lying in between these sheets connect them into a three-dimensional network. © 1990 Plenum Publishing Corporation.