SYNTHESIS, X-RAY-DIFFRACTION ANALYSIS, AND MULTINUCLEAR NMR-STUDY OF (Z)-3,4,4-TRIMETHYL-1-(TRIPHENYLSTANNYL)-1-PENTEN-3-OL AND ITS MONOIODINATED DERIVATIVE

The syntheses of (Z)-3,4,4-trimethyl-1-(triphenylstannyl)-1-pentene-3-ol (1) and (Z)-3,4,4-trimethyl-1-(iododiphenylstannyl)-1-penten-3-ol (2) are reported. The solid-state structures of these tetra- and triorganotin compounds were determined by X-ray diffraction methods. The tin atom in 1 exists in a tetrahedral geometry distorted toward a trigonal bipyramidal one, with the distortion due to the close approach of the OH atom, i.e. 2.772(5) angstrom. A trigonal bipyramidal geometry is found in 2 where the oxygen atom, which forms significant O-->Sn interactions of 2.498(4) and 2.550(4) angstrom for the two independent molecules, respectively, is in an apical position as is the iodine atom. The different strengths of the HO-->Sn interactions are related to the Lewis acidities of the respective tin centers. Crystals of 1 are triclinic, space group P1BAR, with a = 11.120(6) angstrom, b = 11.652(6) angstrom, c = 9.998(5) angstrom, alpha = 110.15(5)-degrees, beta = 106.39(4)-degrees, gamma = 87.74(6)-degrees, V = 1164(1) angstrom 3, and Z = 2. Crystals of 2 are triclinic, space group P1BAR, with a = 12.631(4) angstrom, b = 13.887(1) angstrom, c = 12.252(4) angstrom, alpha = 95.91(2)-degrees, beta = 107.00(3)-degrees, gamma = 74.67(2)-degrees, V = 1981(1) angstrom 3, and Z = 2. The structures were refined to final R = 0.048 for 1 and R = 0.038 for 2. These compounds were characterized in solution by H-1, C-13, and Sn-119 NMR spectroscopy. The existence of an intramolecular HO-->Sn coordination in solution was assessed by C-13 and Sn-119 secondary isotope multiplet of partially labeled entities (SIMPLE-NMR) experiments.