Does hydrogen bonding matter in crystal engineering? Crystal structures of salts of isomeric ions.

The preparation and structure determinations of the crystalline salts [3,3'-H(2)bipy][PtCl(4)] (2), [2,2'-H(2)bipy][PtCl(4)] (3) and [1,4'-Hbipy][PtCl(4)] (4) and [3,3'-H(2)bipy][SbCl(5)] (6) and [1,4'-Hbipy][SbCl(5)] (8) are reported. In addition a redetermination of the structure of the metastable salt [4,4'-H(2)bipy][SbCl(5)] (5 b) in the corrected space group Pbcm is described. These structures are compared to those of the known salt [4,4'-H(2)bipy][PtCl(4)] (1), the stable triclinic form of [4,4'-H(2)bipy][SbCl(5)] (5 a) and [2,2'-H(2)bipy][SbCl(5)] (7).