Acyclic Diaminocarbene Platinum(IV) Complexes Synthesized by the Oxidative Addition of MeI and I2

The oxidative addition of methyl iodide or molecular iodine to the bis(& Scy;,N-chelate) deprotonated diaminocarbene platinum(II) complexes [Pt{C(N(H)Ar)(NC(N(H)Ph)N(Ph)}(2)] (Ar = C6H3-2,6-Me-2 (Xyl), C6H2-2,4,6-Me-3 (Mes), and C6H4-4-Me (pTol)) affords the corresponding platinum(IV) derivatives in a yield of 89-99%. The addition of CF3CO2H is accompanied by the protonation of the nitrogen atoms of the diaminocarbene fragment to form the cationic complexes [PtI(X)-{C(N(H)Ar)(NC-(N(H)Ph)N(Ph)}(2)]CF3CO2H (X = Me, I). The structures of the compounds are determined by elemental analysis; high resolution mass spectrometry with electrospray ionization (ESI HRMS); IR spectroscopy; H-1, C-13{H-1}, F-19{H-1}, and Pt-195{H-1} NMR spectroscopy; 2D NMR spectroscopy (H-1,(1)& Ncy; COSY, H-1,(1)& Ncy; NOESY, H-1,C-13 HSQC, H-1,C-13 HMBC, H-1,N-15 HSQC, H-1,N-15 HMBC), and X-ray diffraction (XRD) and thermogravimetric analyses. The synthesized platinum(IV) complexes are thermally stable to 200-260 degrees C and are electroneutral molecules with the octahedral coordination sphere formed by two deprotonated diaminocarbene C,N-chelate substituents and iodine and methyl or two iodine atoms localized in the apical positions.