The synthesis, structural characterization and reactivity of transition metal phenoxides is rapidly expanding field of study. The phenoxide ion is an important ligand in inorganic chemistry because it provides not only a strong metal-oxygen bond but a flexible organic moiety having an advantage over analogous alkoxide ligands in that electronic properties can easily be varied by changing the substituents in the phenyl ring and steric effects in close proximity to metal can be modified by varying the bulk of substituents at ortho and para positions of the ring. Recent research in the field of metal aryloxides has grown rapidly not only because of their structural properties but also due to their potential applications . This book is divided into four chapters. Each chapter covers different aspects of mixed ligand complexes of zirconium like synthesis, characterization, reactivity, thermal analysis etc. this book is intended to give insight into transition metal phenoxides especially zirconium(IV) and is helpful for students/ researchers who want to pursue research in the area of transition metal chemistry land thermal analysis.