136805-00-0Relevant academic research and scientific papers
Synthesis, reactivity, and characterization of the first donor-stabilized silylene complexes of osmium meso-tetra-p-tolylporphyrin (TTP)Os=SiR2·THF (R = Me, Et, iPr) and the molecular structure of (TTP)Os=SiEt2·2THF
Woo, L. Keith,Smith, Daniel A.,Young Jr., Victor G.
, p. 3977 - 3982 (2008/10/08)
The preparation and characterization of the first donor-stabilized silylene complexes of osmium meso-tetra-p-tolylporphyrin are described. The silylene complex (TTP)Os=SiMe2·THF (1·THF) is prepared by the reaction of [Os(TTP)]2 with hexamethylsilacyclopropane. Treating K2[Os(TTP)] with Cl2SiR2 also generates the silylene complexes (TTP)Os=SiR2·THF [R = Me (1·THF), Et (2·THF), iPr (3·THF)]. 1H NMR spectroscopy indicates that, in solution, one molecule of THF is coordinated to the silicon in all of these complexes. This has been verified by 2D-NOESY experiments. In 2·THF, the methylene protons are diastereotopic, indicating that the silicon is pyramidalized. Addition of 1 equiv of pyridine to 1·THF or 2·THF replaces the THF on silicon with pyridine. Coordination of pyridine to silicon was also confirmed by a 2D-NOESY experiment The structure of 2·THF was determined by a single-crystal X-ray diffraction experiment. The diethyl complex 2·2THF crystallizes with two additional THF molecules as solvates in the monoclinic space group P21/c with a = 21.649 (5) A?, b = 13.829 (3) A?, c = 19.526 (3) A?, β = 98.08 (2)°, V = 5788 (4) A?3, Z = 4, R = 5.0%, and Rw = 5.7%. The Os-Si distance (2.325 (8) A?) is the shortest observed to date. Other metrical parameters of this complex are discussed.
