The hydrogen bonding effect on the halobismuthate(III) geometry: thermal, spectroscopic and structural properties of halobismuthate complexes of 4,6-dimethylpyrimidine-2(1H)-thione

Reactions involving Bi(III) halides and 4,6- dimethylpyrimidine-2(1H)-thione (L) in HX solution result in the formation of [HL]3[BiX6]·2H2O (X=C1, Br) and [HL]3[Bi2I9]. These compounds together with the organic molecule in the form of the hydrochloride, (HLCl) were characterized by means of spectroscopic and thermogravimetric measurements. For HLCl·H2O (1) and [HL]3[BiCl6]·2H2O (2), X-ray structures were determined. In 1, which crystallizes in the space group Pca21, with four molecules in the cell, the structure consists of roughly planar protonated organic molecules stacked along the [100] axis and built up by hydrogen bonds involving chlorine atoms and water molecules. For 2, the space group is P21/n, Z=4, the structure contains [BiCl6]3- anions, protonated organic molecules stacked along the [010] axis and water molecules which form strong hydrogen bonds with the [BiCl6]3- anions. The final R indices are 0.0320 and 0.0465 for 1 and 2, respectively. © 1986