The book entitled "Geometrical structures and thermal studies of azo rhodanine complexes" comprises six main Chapters. The objectives of the present book are: (1) The synthesis, characterization and electronic absorption spectra of mixed ligand of azo rhodanine derivatives, methyl acetoacetate and VO(IV) complexes. (2) Geometrical structures and quantum chemical parameters of the azo rhodanine were discussed and calculated. (3) The synthesis and characterization of complexes of palladium(II) electron donors mixed ligand derived from bis(1,3-diketonato) palladium(II) (4) The synthesis of 5-(4'-derivatives phenylazo)-2-thioxo-4-thiazolidinone (HLn) and their Cu(II) complexes (5) The thermogravimetric analysis (TGA) and differential scanning calorimetry analysis (DSC) studies for HLn. (6) The structure of the isolated complexes is elucidated using elemental analysis, IR spectral, magnetic moment, ESR and thermogravimetric analysis. (7) The activation thermodynamic parameters were calculated using Coats-Redfern and Horowitz-Metzger methods.