dibromo(dihydrido)osmium;tri(propan-2-yl)phosphane | 192191-36-9

• 分子结构分类: 有机化合物 - 有机盐 - 有机金属盐
• 英文名称: dibromo(dihydrido)osmium;tri(propan-2-yl)phosphane
• CAS: 192191-36-9；159903-28-3；159992-39-9
• 化学式: C₁₈H₄₄Br₂OsP₂
• 分子量: 672.503
• InChiKey: YXVJRSRXKCXKQY-UHFFFAOYSA-L

计算性质

• 辛醇/水分配系数(LogP)：
  8.54
• 重原子数：
  23.0
• 可旋转键数：
  8.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为反应物：
  描述：

  dibromo(dihydrido)osmium;tri(propan-2-yl)phosphane 、 氢气 以 not given 为溶剂， 生成
  参考文献：
  名称：

  Dihydrogen addition to (PiPr3) 2OsX H4−

  摘要：

  Reaction of H-2 with L2Os(X)(Y)(H)(2) (L=(PPr3)-Pr-i; X, Y = Cl, Br, I) slowly (minutes) gives a 1:1 'adduct'. The X-ray structure of L2OsH4Br2 shows, like the chloride analog, a substantial change in geometry upon reaction with H-2, to give a heavy atom OsX2L2 skeleton of C-2v geometry, with cis halides and trans phosphines. Attempts are made to distinguish between Os(H)(4), Os(H-2)(2) and Os(H)(2)(H-2) structures using J(HD) and T-1min criteria. Study of L2OsXnH4-n species shows no monotonic trend in the Delta G(double dagger) for H-2 loss, being higher for both n=0 and n=2 than for n=1. Studied as a function of X(=Cl, Br, I), H-2 binding to L2Os(H)(2)X-2 is favored enthalpically but disfavored entropically for the larger, least electronegative halide. The X-ray structure of L2OsDCl3 shows this unsaturated species to have significant angular distortions from octahedral geometry, consistent with its diamagnetic character. (C) 1997 Elsevier Science S.A.

  DOI：

  10.1016/s0022-328x(96)06914-8
• 作为产物：
  描述：

  三甲基溴硅烷 、 OsH₂Cl₂(P(C₃H₇)3)2 以 二氯甲烷 为溶剂， 生成 dibromo(dihydrido)osmium;tri(propan-2-yl)phosphane
  参考文献：
  名称：

  Structural and Dynamic Properties of OsH2X2L2 (X = Cl, Br, I; L = PiPr3) Complexes: Interconversion between Remarkable Non-Octahedral Isomers

  摘要：

  Proton and P-31 NMR data reveal that the molecules Os(H)(2)X(2)L(2) (X = halide, L = (PPr3)-Pr-i) exist in solution as two rapidly interconverting isomers, one having C-2 symmetry (as seen in the solid-state structure) and one having no symmetry. Three distinct intramolecular rearrangements were detected and quantified (Delta G(double dagger)), and P/H coupling constants were employed to estimate P-Os-H angles in the nonsymmetric isomer. The geometries of these two isomers were determined at the MP2 level by gradient method with effective core potential ab initio calculations. The geometry calculated for the symmetric isomer is a distorted octahedron with C-2v symmetry; The solid-state structure, which resembles the calculated symmetric structure, is shown to be the result of opposing forces: steric interactions between phosphine and chlorine ligands and bonding preference of the chlorine ligands. The structure of the nonsymmetric isomer is related to the structure calculated for the symmetric isomer by exchange of one hydride for one chloride together with further slight geometric distortions. Using the calculated structures, physical mechanisms for all observed fluxionality are proposed.

  DOI：

  10.1021/ja00106a031

文献信息

• Site Selectivity in Electrophilic (H⁺, CH₃⁺) Abstraction on Os(H)₂X₂(PⁱPr₃)₂
  作者：Roger Kuhlman、William E. Streib、John C. Huffman、Kenneth G. Caulton

  DOI：10.1021/ja960369h

  日期：1996.1.1

  by MeOTf into L2Os(H)2(OTf)I, then L2Os(H)2(OTf)2, a non-octahedral Lewis acid which binds H2O to form the intramolecularly hydrogen bonded L2Os(H)2(OTf)2(H2O), whose intramolecular fluxionality has been characterized (1H and 31P NMR). The complexes L2Os(H)2(ORf)2 (ORf = OCH2CF3 and OCH(CF3)2) are synthesized from L2Os(H)2Cl2 and TlORf. The X-ray structure of L2Os(H)2(OCH2CF3)2 shows evidence for O→Os

  虽然 Os(H)2X2L2 (L = PiPr3, X = Cl, Br) 的质子化 (HBF4 或 HO3SCF3 = HOTf) 或甲基化 (MeOTf) 提取卤化物并导致聚集形成 (L2OsH2)2(μ-X)3+， Os(H)2I2L2 质子化形成一种物质，其 -7.5 ppm 1H NMR 化学位移具有 H2 复合物的短 T1min 特征（或短 H/H 接触）。这也得到了 OsH3I2L2+ 共振的显着同位素扰动的支持，尽管在 OsHD2I2L2+ 中没有观察到 J(HD)。相比之下，Os(H)2I2L2 被 MeOTf 转化为 L2Os(H)2(OTf)I，然后 L2Os(H)2(OTf)2，一种非八面体路易斯酸，它与 H2O 结合形成分子内氢键的 L2O (H)2(OTf)2( )，其分子内流动性已被表征（1H 和 31P NMR）。复合物 L2Os(H)2(ORf)2 (ORf
• Quantum Exchange Coupling:  A Hypersensitive Indicator of Weak Interactions
  作者：Roger Kuhlman、Eric Clot、Claude Leforestier、William E. Streib、Odile Eisenstein、Kenneth G. Caulton

  DOI：10.1021/ja970603j

  日期：1997.10.1

  Os(H)(3)ClL2 (L = (PPr3)-Pr-i) forms a 1:1 adduct with L' = PEt3, NH3, MeCN, acetone, methanol, and THF. The case L' = PEt3 permits the dearest identification of adduct structure as pentagonal bipyramidal. For NH3 and MeCN, the respective kinetics of L' loss are measured as Delta H-double dagger = 20.7(3) and 17.6(3) kcal/mol and Delta S-double dagger = 16(1) and 14.7(9) cal/(mol K). For acetone, methanol, and THF, the following respective Delta H degrees and Delta S degrees values for L' binding are measured: Delta H degrees = -10.4(1), -6.66(8), and -5.8(2) kcal/mol; Delta S degrees = -41.8(5), -25.5(3), and -33(1) cal/(mol K). Decoalesced H-1 NMR spectra are reported for several of these Os(H)(3)ClL2L' species, and they show a variety of examples of quantum exchange coupling among the hydride ligands. The values of J(e)x are higher when L' is a more weakly-binding ligand. The quantum exchange coupling constants of Os(H)(3)XL2 (X = Cl, Br, I, OCH2CF3, OCH(CF3)(2)) in CD2Cl2, in toluene, and in methylcyclohexane show an unprecedented decrease of J with increasing temperature, which is attributed to weak formation of Os(H)(3)Cl(solvent)L-2 adducts at low temperature. For L' = CO, adduct formation leads to liberation of coordinated H-2. Excess L' = MeCN or NH3 slowly leads to formation of [Os(H)(3)L'L-2(2)]Cl; the X-ray structure for L' = NH3 is reported. Crystal data (-171 degrees C): a = 11.561(4) Angstrom, b = 14.215(5) Angstrom, c = 8.851(3) Angstrom, alpha = 97.51(2)degrees, beta = 107.73(2)degrees, gamma = 104.47(2)degrees, with Z = 2 in space group . The potential energy was calculated for exchange of 2H of OsH3X(PH3)(2)L (X = Cl with L = no ligand and PH3, X = I with L = no ligand) using effective core potential ab initio methods at the MP2 level. The site exchange is found to be energetically easier for Cl than for I, in agreement with experiment. The hydride site exchange in the seven-coordinate species OsH3Cl(PH3)(3) (a model for coordination of either ligand or solvent to Os) is found to be easier than that in the 16-electron species. No dihydrogen ligand is located on the reaction path for site exchange. The current theory which relates quantum exchange to a tunneling effect was used for calculating J(ex) as a function of temperature. The dynamic study was done using several sets of coordinates, in particular the rotation angle phi and the internuclear distance r between the exchanging H. The vibrational levels have been calculated and the symmetry of each level assigned within the permutation group in order to determine the nature of the nuclear spin function associated with each level. It is found that the rotation, phi, gives rise to the largest tunneling effect but that r cannot be neglected. The influence of the temperature, J(ex)(T), was included by a Boltzmann distribution. The results are in qualitative agreement with experiment in that quantum exchange coupling is larger in the case of Cl than in the case of I. Additional ligand L increases the value of the quantum exchange coupling mostly by lowering the activation energy for pairwise exchange.