The study emphasized azomethine coordination compounds of Pt(II), Cu(II), and Ni(II) having tetracoordinate geometry around the metal ions with the general formula, [MLCl]Cl, where L, azomethine have been isolated in the solid state. All the ligands were identified by spectroscopic methods and elemental analysis. The synthesized coordination compounds have been characterized by FTIR, magnetic measurements, elemental analysis, electrical conductance, and thermal analysis. Square planar structures have been proposed for the Ni(II) and Pt(II) complexes. Magnetic susceptibility measurements and electronic spectra of the complexes sustain the proposed square planer structures. The complexes thermally stable and this thermal stability is discussed in terms of ligands donor atoms, geometry and central metal ions. Azomethine complexes have a similar thermal behavior for the selected metal ions. The TG analyses suggest high thermal stability for most complexes followed by thermal decomposition in different steps. The decomposition processes were observed as water elimination, chloride anion removal, and degradation of the organic ligands. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file.