Viewpoints Concerning Crystal Structure from Recent Reports on Schiff Base Compounds and Their Metal Complexes

Schiff bases are organic compounds that are often used as ligands in metal complexes. In addition to the C=N double bond, which is characteristic of Schiff bases, intermolecular hydrogen bonds are frequently observed in both the twisting of planar substituents in organic compounds and the geometric structure of the coordination environment in metal complexes. The results of the crystal structure analyses are stored in databases, which can be used to assess three-dimensional structures. To examine the important structural aspects for novel molecular and material designs, this review examines the important discussion of crystal structure “features” from various viewpoints based on papers on Schiff bases and Schiff base metal complexes from recent years.