The book describes the syntheses and crystal structures of Cu(II) and Ni(II) complexes with some N and N,O donor ligands along with coligands like pseudohalides, perchlorate, chloride, hydroxo etc. The structural diversity of the species, which is dependent on the metal ion as well as on the anionic coligands, has been rationalized. The variable temperature magnetic properties of the some complexes have also been included to get a thorough understanding of the coupling between the metal ions and their expected magnetic behavior. The book consists of four chapters of which Chapter I deals with an overview on the Cu(II) and Ni(II) complexes with some N and N,O donor ligands along with coligands like pseudohalides, perchlorate, chloride, hydroxo etc., and Chapters II-IV describe details of syntheses, crystal structures and different physical properties of complexes. In keeping with the general practice of reporting scientific observations, due acknowledgements have been made of the findings of other investigators. I take the responsibility of any unintentional oversights and errors, which might have crept in despite precautions.