Coordination Architectures of Large Heavy Metal Cations (Hg 2+ and Pb 2+ ) with Bis‐tridentate Ligands: Solution and Solid‐State Studies

Solution and solid state studies of the complexation of Hg 2+ and Pb 2+ by the homologous bis‐tridentate ligands 1 and 2 H 2 obtained by condensation of bis(methylhydrazino)phenylpyrimidine and bis(hydrazino)phenylpyrimidine, respectively, with pyridine‐2‐carboxaldehyde, have provided evidence for the formation of both grid and rack species. With Hg 2+ , there is little indication for other than grid species, the grid complex [Hg 4 ( 2 H 2 ) 4 ](CF 3 SO 3 ) 8 being characterised crystallographically. With Pb 2+ , the only crystalline species readily isolated are rack complexes of the ligands 1 and 2 H 2 .