[HNiFe(1,3-propanedithiolate)(1,2-bis(diphenylphosphino)ethane)(PPh2Py)(CO)2][BF4] | 1253891-55-2

• 英文名称: [HNiFe(1,3-propanedithiolate)(1,2-bis(diphenylphosphino)ethane)(PPh2Py)(CO)2][BF4]
• CAS: 1253891-55-2
• 化学式: BF₄*C₄₈H₄₅FeNNiO₂P₃S₂
• 分子量: 1026.29
• InChiKey: KZTBVXSYAJJPCT-UHFFFAOYSA-L

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
  None
• 环数：
  None
• sp3杂化的碳原子比例：
  None
• 拓扑面积：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为反应物：
  描述：

  [HNiFe(1,3-propanedithiolate)(1,2-bis(diphenylphosphino)ethane)(PPh2Py)(CO)2][BF4] 、 三氟乙酸 以 二氯甲烷 为溶剂， 生成 [HNiFe(1,3-propanedithiolate)(1,2-bis(diphenylphosphino)ethane)(PPh2PyH)(CO)2][CF3CO2]2
  参考文献：
  名称：

  Hydride-Containing Models for the Active Site of the Nickel−Iron Hydrogenases

  摘要：

  The [NiFe]-hydrogenase model complex NiFe(pdt)(dppe)(CO)(3) (1) (pdt = 1,3-propanedithiolate) has been efficiently synthesized and found to be robust. This neutral complex sustains protonation to give the first nickel-iron hydride [1H]BF4. One CO ligand in [1H]BF4 is readily substituted by organophosphorus ligands to afford the substituted derivatives [HNiFe(pdt)(dppe)(PR3)(CO)(2)]BF4, where PR3 = P(OPh)(3) ([2H]BF4); PPh3 ([3H]BF4); PPh2Py ([4H]BF4, where Py = 2-pyridyl). Variable temperature NMR measurements show that the neutral and protonated derivatives are dynamic on the NMR time scale, which partially symmetrizes the phosphine complex. The proposed stereodynamics involve twisting of the Ni(dppe) center, not rotation at the Fe(CO)(2)(PR3) center. In MeCN solution, 3, which can be prepared by deprotonation of [3H]BF4 with NaOMe, is about 10(4) stronger base than is 1. X-ray crystallographic analysis of [3H]BF4 revealed a highly unsymmetrical bridging hydride, the Fe-H bond being 0.40 angstrom shorter than the Ni-H distance. Complexes [2H]BF4, [3H]BF4, and [4H]BF4 undergo reductions near -1.46 V vs Fc(0/+). For [2H]BF4, this reduction process is reversible, and we assign it as a one-electron process. In the presence of trifluoroacetic acid, proton reduction catalysis coincides with this reductive event. The dependence of i(c)/i(p) on the concentration of the acid indicates that H-2 evolution entails protonation of a reduced hydride. For [2H](+), [3H](+), and [4H](+), the acid-independent rate constants are 50-75 s(-1). For [2H](+) and [3H](+), the overpotentials for H-2 evolution are estimated to be 430 mV, whereas the overpotential for the N-protonated pyridinium complex [4H(2)](2+) is estimated to be 260 mV. The mechanism of H-2 evolution is proposed to follow an ECEC sequence, where E and C correspond to one-electron reductions and protonations, respectively. On the basis of their values for its pK(a) and redox potentials, the room temperature values of Delta G(H center dot) and Delta G(H center dot) are estimated as respectively as 57 and 79 kcal/mol for [1H](+).

  DOI：

  10.1021/ja105312p
• 作为产物：
  描述：

  二苯基-2-吡啶膦 、 [(dppe)Ni(pdt)(μ-H)Fe(CO)₃]BF₄ 以 四氢呋喃 为溶剂， 以59%的产率得到[HNiFe(1,3-propanedithiolate)(1,2-bis(diphenylphosphino)ethane)(PPh2Py)(CO)2][BF4]
  参考文献：
  名称：

  Hydride-Containing Models for the Active Site of the Nickel−Iron Hydrogenases

  摘要：

  The [NiFe]-hydrogenase model complex NiFe(pdt)(dppe)(CO)(3) (1) (pdt = 1,3-propanedithiolate) has been efficiently synthesized and found to be robust. This neutral complex sustains protonation to give the first nickel-iron hydride [1H]BF4. One CO ligand in [1H]BF4 is readily substituted by organophosphorus ligands to afford the substituted derivatives [HNiFe(pdt)(dppe)(PR3)(CO)(2)]BF4, where PR3 = P(OPh)(3) ([2H]BF4); PPh3 ([3H]BF4); PPh2Py ([4H]BF4, where Py = 2-pyridyl). Variable temperature NMR measurements show that the neutral and protonated derivatives are dynamic on the NMR time scale, which partially symmetrizes the phosphine complex. The proposed stereodynamics involve twisting of the Ni(dppe) center, not rotation at the Fe(CO)(2)(PR3) center. In MeCN solution, 3, which can be prepared by deprotonation of [3H]BF4 with NaOMe, is about 10(4) stronger base than is 1. X-ray crystallographic analysis of [3H]BF4 revealed a highly unsymmetrical bridging hydride, the Fe-H bond being 0.40 angstrom shorter than the Ni-H distance. Complexes [2H]BF4, [3H]BF4, and [4H]BF4 undergo reductions near -1.46 V vs Fc(0/+). For [2H]BF4, this reduction process is reversible, and we assign it as a one-electron process. In the presence of trifluoroacetic acid, proton reduction catalysis coincides with this reductive event. The dependence of i(c)/i(p) on the concentration of the acid indicates that H-2 evolution entails protonation of a reduced hydride. For [2H](+), [3H](+), and [4H](+), the acid-independent rate constants are 50-75 s(-1). For [2H](+) and [3H](+), the overpotentials for H-2 evolution are estimated to be 430 mV, whereas the overpotential for the N-protonated pyridinium complex [4H(2)](2+) is estimated to be 260 mV. The mechanism of H-2 evolution is proposed to follow an ECEC sequence, where E and C correspond to one-electron reductions and protonations, respectively. On the basis of their values for its pK(a) and redox potentials, the room temperature values of Delta G(H center dot) and Delta G(H center dot) are estimated as respectively as 57 and 79 kcal/mol for [1H](+).

  DOI：

  10.1021/ja105312p