| 138606-15-2

• 分子结构分类: 有机化合物 - 有机杂环化合物
• CAS: 138606-15-2
• 化学式: C₄₄H₃₂O₄Ti
• 分子量: 672.616
• InChiKey: LWUUDYMXLUBMCF-UHFFFAOYSA-J

反应信息

• 作为产物：
  描述：

  、 四氯化钛 以 乙醚 为溶剂， 生成
  参考文献：
  名称：

  钛（IV）双邻苯二甲酸酯配合物中分子内和分子间重排的动力学和热力学

  摘要：

  3,3'-Disubstituted-1,1'-bi-2-naphthols (H2R2BINO where R = Me or SiMe2-t-Bu) react with Ti(O-i-Pr)4 to produce molecules of empirical formula [(R2BINO)Ti(O-i-Pr)2]n. Analytical methods including NMR spectroscopy, molecular weight cryoscopy, and X-ray crystallography were used to identify the (t-BuMe2Si)2BINO-substituted complex as a monomer and the Me2BINO-substituted complex as a dimer. This dinuclear complex possesses a highly distorted edge-fused trigonal-bipyramidal structure, whose 1,3-Ti2O2 core is bridged by two naphthoxide units. There is a distinct thermodynamic preference for the incorporation of ligands of like chirality into the dimer. A second set of complexes having empirical formula (R2BINO)Ti2(O-i-Pr)6 (R = Me, SiMe2-t-Bu) are accessible through either the reaction of 2 equiv of Ti(O-i-Pr)4 with H2R2BINO or a reaction between [(R2BINO)Ti(O-i-Pr)2]n and Ti(O-i-Pr)4. The (Me2BINO)Ti2(O-i-Pr)6 complex possesses C1 symmetry at the low-temperature limit, implying that the molecule adopts an edge-fused trigonal-bipyramidal structure bridged by one naphthoxide and one isopropoxide ligand. At higher temperatures, a fluxional process, (DELTA-G double-ended dagger 240 = 10.8 kcal/mol) generates time-averaged C2 symmetry consistent with the rupture of the isopropoxide bridge to produce a binaphtholate ligand bound to two ''Ti(O-i-Pr)3'' units. {(t-BuMe2Si)2BINO}Ti2(O-i-Pr)6 adopts this C2-symmetric structure in both solution and the solid state. Both the (Me2BINO)Ti2(O-i-Pr)6 and {(t-BuMe2Si)2BINO}Ti2(O-i-Pr)6 complexes display temperature-dependent equilibria in solution between Ti(O-i-Pr)4 and either [(Me2BINO)Ti(O-i-Pr)2]2 or {(t-BuMe2Si)2BINO}Ti(O-i-Pr)2, respectively. The thermodynamic characteristics of these equilibria follow: Me2BINO, DELTA-H-degrees = -12.5 +/- 0.6 kcal/mol, DELTA-S-degrees = 38 +/- 2 eu; (t-BuMe2Si)2BINO, DELTA-H-degrees = -12.0 +/- 0.8 kcal/mol, DELTA-S-degrees = -44 +/- 4 eu. The (Me2BINO)Ti2(O-i-Pr)6 complex also engages in an independent intermolecular exchange processes in which a ''Ti(O-i-Pr)4'' unit is exchanged with free Ti(O-i-Pr)4 in solution (DELTA-H double-ended dagger = 14.1 +/- 0.9 kcal/mol, DELTA-S double-ended dagger = -2 +/- 2 eu). When compared with the previously observed fluxional process in (Me2BINO)Ti2(O-i-Pr)6, this observation demonstrates that polynuclear titanium complexes can engage in distinct intramolecular and intermolecular exchange processes. Crystal data for {(t-BuMe2Si)2BINO}Ti(O-i-Pr)2 at 113 K: a = 10.866 (3) angstrom, b = 15.572 (4) angstrom, c = 23.059 (4) angstrom, beta = 93.76 (2)-degrees, Z = 4, D(calc) = 1.152, space group P2(1)/c, R(F) = 0.037, R(W)(F) = 0.051 for 3861 reflections. Crystal data for [(Me2BINO)Ti(O-i-Pr)2]2 at 106 K: a = 17.728 (3) angstrom, b = 11.079 (4) angstrom, c = 26.232 (4) angstrom, beta = 101.00 (3)-degrees, Z = 4, D(calc) = 1.257, space group P2(1)/c, R(F) = 0.069, R(W)(F) = 0.077 for 3231 reflections. Crystal data for {(t-BuMe2Si)2BINO}Ti2(O-i-Pr)6 at 113 K: a = 14.444 (2) angstrom, b = 18.676 (3) angstrom, c = 20.788 (4) angstrom, beta = 98.76 (2)-degrees, Z = 4, D(calc) = 1.143, space group C2/c, R(F) = 0.059, R(W)(F) = 0.091 for 2860 reflections.

  DOI：

  10.1021/om00039a017