Reactivity of SiMe3-and SnR3-functionalized Bis(7-azaindol-1-yl)methane with [PtR2(μ-SMe)] (R = Me, Ph) and the resulting Pt(II) and Pt(IV) complexes

new bis(7-azaindol-1-yl)methane (BAM) derivative ligands Me ₃Si-BAM (1a), Me₃Sn-BAM (1b), and Ph₃Sn-BAM (1c) have been synthesized, and their reactivities with [PtR₂(μ- SMe2)] _n (R = Me, Ph) have been examined. Two Pt(II) complexes Pt(Me₃Si-BAM)R₂₀ (R = Me, 2; Ph, 3) were obtained from the reactions of 1a. The reactions of 1b with [PtR₂ (μ-SMe2)] _n (R = Me, Ph) produced unexpected novel N,C,N-BAM Pt(IV) complexes Pt(N, C,N-BAM)(SnMe₃)R₂ (R = Me, 4; Ph, 6) likely via oxidative cleavage of the C_BAM-Sn bond in 1b. 1c reacted with [PtPh2(μ-SMe2)] _n (n = 2, 3) yielding the anticipated Pt(II) complex Pt(Ph3Sn-BAM)Ph2 (7), whereas its reaction with [PtMe₂ (μ-SMe₂)]₂ resulted in unusual Ptn-Me and SnIV-Ph metathesis, yielding also 7 as one of the products. Mechanistic investigation was carried out to understand this phenomenon. The reactivities of 2 with MeI, MeOTf, and I2 were examined. Its reaction with I2 gave rise to Pt(Me3Si-BAM)I2 (9) along with CH3I, indicating the possibility of functionalizing PtII-Me via iodinolysis. The reaction of Pt(N,C,N-BAM)(SnMe3)Me2 (4) with I2 produced a number of unusual N,C,N-BAM Pt(IV) complexes including Pt(N,C,N-BAM)Me(I) (SnI2Me) (13) and Pt(N,C,N-BAM)Me(I)(I3)(14) due to the electrophilic cleavage of the Sn-Me, Pt-Me and/or Pt-Sn bond(s) by I2. For comparison, we also investigated the reaction of Pt(N,C,N-BAM)Me3 (M1) with I2 which was found to exhibit a high regioselectivity for the axial Pt-Me group, resulting in Pt(N,C,N-BAM)Me2(I3)(15) with the two Pt-Me being cis to each other. The reactions of 4 and M1 with I2 are rare examples of PtIV- CH3 bond cleavage by the elimination of CH3I. The structures of 1a and complexes 2, 7, 9, and 13- 15 were determined by X-ray diffraction analyses.