Cyclometalated Platinum Compounds from Competing C–H/C–X Bond Activation Pathways

X–CNN (X = Br, Cl) ligands were reacted with Pt2Me4 (μ-SMe2) 2, 1, resulting in a six-coordinate cyclometalated platinum (IV) compound containing an anionic CNN ligand when X = Br and both a platinum (IV) and a platinum (II) product when X = Cl. The platinum (II) species was formed by C–H activation, followed by reductive elimination of methane. The platinum compounds were characterized by multinuclear NMR spectroscopy and single-crystal X-ray diffraction (SCXRD). Photophysical properties were explored by using UV/vis, emission, and transient absorption (TA) spectroscopies. DFT and TDDFT calculations were performed to examine the competition between C–H activation and C–X oxidative addition and compared to experimental results.