METALATION OF THE CROWN THIOETHER LIGAND 2,6,10-TRITHIA[11]-META-CYCLOPHANE (TT[11]MC) - SYNTHESIS, STRUCTURE, AND REACTIVITY OF [PT(TT[11]MC)][BF4] AND STRUCTURES OF [PT(PPH2ME)(TT[11]MC)][BF4] AND [PTI2(TT[11]MC)][BF4]

The reaction of PtCl2(1,5-COD) with the 1,3-xylyl-containing crown thioether 2,6,10-trithia[ll]-m-cyclophane TT[ll]MC) in the presence of 1 equiv of AgBF4 yielded [Pt(TT[ll]MC)][BF4]. H-1 and (C{H})-C-13-H-1 NMR spectroscopy indicated that metalation of the ligand at the 2-position of the aromatic ring had and this was verified by an X-ray crystal structure. The complex [Pt(TT[ll]MC)][BF4] Crystallized in the space group P2(1)/c with a = 8.373 (1) angstrom, b = 21.784 (7) angstrom, c = 9.517 (4) angstrom, beta = 95.09 (2)-degrees, V = 1729.1 (16) angstrom3, and Z = 4. The structure was refined to R = 6.93% and R(w) = 6.99% for 1885 reflections with F(o)2 > 3-sigma(F(o)2). The Pt atom is in a square-planar environment, bonded to the three S atoms and the aromatic C atom of the macrocycle. In the presence of strong donors such as PPh2Me, [Pt(TT[ll]MC)][BF4] undergoes substitution reactions for the S donor trans to the Pt-C bond. The product [Pt(PPh2Me)-(TT[11]MC)][BF4] was characterized by H-1, (C{H})-C-13-H-1, and (P{H})-P-31-H-1 NMR spectroscopy as well as an X-ray crystal structure. The complex [Pt(PPh2Me)(TT[11]MC)][BF4] crystallized in the space group P2(1)/n with a = 9.933 (2) angstrom, b = 20.163 (3) angstrom, c = 14.490 (2) angstrom, beta = 94.88 (2)-degrees, V = 2891.6 (16) angstrom3, and Z = 4. The structure was refined to R = 5.91% and R(w) = 6.14% for 2841 reflections with F(o)2 > 3-sigma(F(o)2). The Pt atom is in a square-planar environment, bonded to the two mutually trans S atoms, the PPh2Me ligand, and the aromatic C atom of the macrocycle. The remaining S atom is oriented away from the metal center with the aliphatic chain perpendicular to the square plane. [Pt(TT[11]MC)][BF4] also undergoes oxidative-addition reactions with I2 and CuCl2 to produce octahedral Pt(IV) complexes of the type [PtX2(TT[11]MC)][BF4]. These complexes were characterized by H-1 and (C{H})-C-13-H-1 NMR spectroscopy and an X-ray crystal structure of [PtI2(TT[11]MC)][BF4]. The complex [PtI2(TT[11]MC)][BF4] Crystallized in the space group P2(1)/n with a = 11.253(4) angstrom, b = 11.120(2) angstrom, c = 16.558(4) angstrom, beta = 99.53(3)-degrees, V = 2043 (2) angstrom3, and Z = 4. The structure was refined to R = 6.50% and R(w) = 6.95% for 2464 reflections with F(o)2 > 3-sigma(F(o)2). The Pt atom is in an octahedral environment, comprised of the three S atoms, the xylyl C atom of the macrocycle, and the two added I atoms, which are mutually cis in positions trans to C and trans to the central S atom.