The distorted square pyramidal structures of the Pt(II) and Pd(II) complexes with cyclometallated 2-phenylbenzothiazole and flexible 1,4,7-trithiocyclononane are shown by X-ray diffraction analysis, IR spectroscopy, and ¹Н, ¹³С{¹H{, and ¹⁹⁵Pt NMR spectroscopy. The axial interaction of the d_Z2 orbital of Pt(II) and Pd(II) with the S atom of 1,4,7-trithiocyclononane results in the temperature quenching of the intraligand phosphorescence of the cyclometallated complexes in a solution and the one-electron ligand- and metal-centered reduction and oxidation of the complexes with the formation of the relatively stable Pd(III) complex (CIF file CCDC no. 1483011).