Crystal and molecular structure of two tetradentate "oxime-and-amide" ligands

Syntheses and X-ray structure analyses of two new tetradentate ligands with "oxime-and-amide" donor systems (N,N'-bis(2-hydroiminopropionyl)-1,2-diami noethane and N,N'-bis(2- hydroxyiminopropionyl)-1,4-diaminobutane) were per formed. The overall conformation of both ligands is distinctly different fr om that reported earlier for N,N'-bis(2-hydroxyiminopropionyl)-1,2-diaminop ropane. The number of methylene groups critically influences the ligand geo metry and may have distinct impact on the co-ordinating ability of the liga nds.