{κP,κC,κP-2,6-(i-Pr₂PO)₂-3,5-t-Bu₂-C₆H₂}NiBr | 1415229-50-3

• 英文名称: {κP,κC,κP-2,6-(i-Pr₂PO)₂-3,5-t-Bu₂-C₆H₂}NiBr
• CAS: 1415229-50-3
• 化学式: C₂₆H₄₇BrNiO₂P₂
• 分子量: 592.199
• InChiKey: CQQYPONZSKQXHU-UHFFFAOYSA-M

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：

  {κP,κC,κP-2,6-(i-Pr₂PO)₂-3,5-t-Bu₂-C₆H₂}NiBr 、 silver trifluoromethanesulfonate 、 乙腈 反应 3.0h， 以87%的产率得到
  参考文献：
  名称：

  镍的POCOP型钳式配合物：新型阳离子乙腈加合物的合成，表征和配体交换反应性。

  摘要：

  This report describes the synthesis, characterization, and ligand exchange studies of a family of cationic acetonitrile adducts of nickel featuring resorcinol-based, pincer-type POCOP ligands. The compounds [(R-POCOPR')Ni(NCMe)][OSO2CF3] (R-POCOPR' = 2,6-(R'2PO)(2)(RnC(6)H(3)n); R' = i-Pr: R = H (1), p-Me (2), p-OMe (3), p-CO2Me (4), p-Br (5), m,m-t-Bu2 (6), m-OMe (7), m-CO2Me (8); R' = t-Bu: R = H (9), p-CO2Me (10)) were prepared in 80-93% yields by reacting the corresponding charge-neutral bromo derivatives with Ag(OSO2CF3) in acetonitrile. The impact of the R- and R'-substituents on electronics and structures of 1-10 have been probed by NMR, UVvis, and IR spectra, X-ray crystallography, and cyclic voltammetry measurements. The observed nu(C=N) values were found to increase with the increasing electron-withdrawing nature of R, i.e., in the order 7 < 3 similar to 2 similar to 6 < 1 < 5 similar to 8 < 4 and 9 < 10. This trend is consistent with the anticipation that enhanced electrophilicity of the nickel center should result in an increase in net MeCN -> Ni sigma-donation. That this transfer of electron density from acetonitrile to the nickel center does not adequately counteract the impact of electron-withdrawing substituents was evident from the measured redox potentials: the MeO2C-substituted cations showed the highest oxidation potentials. Moreover, all cationic adducts showed greater oxidation potentials compared with their corresponding charge-neutral bromo precursors. Equilibrium studies conducted with selected [(R-POCOPR')Ni(NCMe)][OSO2CF3] and (R-POCOPR')NiBr (R' = i-Pr) have confirmed facile MeCN/Br exchange between these derivatives and show that the cationic adducts are stabilized with MeO-POCOP, whereas the charge-neutral bromo species are stabilized with MeO2C-POCOP. The potential implications of these findings for the catalytic reactivities of the title cationic complexes have been discussed.

  DOI：

  10.1021/acs.organomet.5b00272
• 作为产物：
  描述：

  4,6-二叔丁基间苯二酚 在 三乙胺 作用下， 以 四氢呋喃 为溶剂， 反应 1.0h， 生成 {κP,κC,κP-2,6-(i-Pr₂PO)₂-3,5-t-Bu₂-C₆H₂}NiBr
  参考文献：
  名称：

  镍的POCOP型钳式配合物：新型阳离子乙腈加合物的合成，表征和配体交换反应性。

  摘要：

  This report describes the synthesis, characterization, and ligand exchange studies of a family of cationic acetonitrile adducts of nickel featuring resorcinol-based, pincer-type POCOP ligands. The compounds [(R-POCOPR')Ni(NCMe)][OSO2CF3] (R-POCOPR' = 2,6-(R'2PO)(2)(RnC(6)H(3)n); R' = i-Pr: R = H (1), p-Me (2), p-OMe (3), p-CO2Me (4), p-Br (5), m,m-t-Bu2 (6), m-OMe (7), m-CO2Me (8); R' = t-Bu: R = H (9), p-CO2Me (10)) were prepared in 80-93% yields by reacting the corresponding charge-neutral bromo derivatives with Ag(OSO2CF3) in acetonitrile. The impact of the R- and R'-substituents on electronics and structures of 1-10 have been probed by NMR, UVvis, and IR spectra, X-ray crystallography, and cyclic voltammetry measurements. The observed nu(C=N) values were found to increase with the increasing electron-withdrawing nature of R, i.e., in the order 7 < 3 similar to 2 similar to 6 < 1 < 5 similar to 8 < 4 and 9 < 10. This trend is consistent with the anticipation that enhanced electrophilicity of the nickel center should result in an increase in net MeCN -> Ni sigma-donation. That this transfer of electron density from acetonitrile to the nickel center does not adequately counteract the impact of electron-withdrawing substituents was evident from the measured redox potentials: the MeO2C-substituted cations showed the highest oxidation potentials. Moreover, all cationic adducts showed greater oxidation potentials compared with their corresponding charge-neutral bromo precursors. Equilibrium studies conducted with selected [(R-POCOPR')Ni(NCMe)][OSO2CF3] and (R-POCOPR')NiBr (R' = i-Pr) have confirmed facile MeCN/Br exchange between these derivatives and show that the cationic adducts are stabilized with MeO-POCOP, whereas the charge-neutral bromo species are stabilized with MeO2C-POCOP. The potential implications of these findings for the catalytic reactivities of the title cationic complexes have been discussed.

  DOI：

  10.1021/acs.organomet.5b00272

文献信息

• Impact of Backbone Substituents on POCOP-Ni Pincer Complexes: A Structural, Spectroscopic, and Electrochemical Study
  作者：Boris Vabre、Denis M. Spasyuk、Davit Zargarian

  DOI：10.1021/om3009475

  日期：2012.12.24

  When treated at room temperature and in the presence of NEt3 with (i-PrCN)NiBr2}(n), the pincer-type ligands R-(POCOPR')-O-H undergo direct C-H nickellation to give the pincer complexes (R-POCOPR')NiBr in 45-92% yields (R-POCOP = kappa(P),kappa(C),kappa(P)-R-n-2,6-(R'2PO)(2)C6H3-n}; R-n = 4-OMe, 4-Me, 4-CO2Me, 3-OMe, 3-CO2Me, 3,5-t-Bu-2; R' = i-Pr, t-Bu). These complexes have been characterized by multinuclear NMR and UV-vis spectroscopy as well as single-crystal X-ray diffraction studies to delineate the impact of R and R' on Ni-ligand interactions. The solid-state structural data have revealed slightly shorter Ni-Br bonds in the complexes bearing a 4-CO2Me substituent, shorter Ni-P bonds in the complex bearing t-Bu substituents at the 3- and 5-positions, and longer Ni-P bonds in complexes featuring OP(t-Bu)(2) donor moieties. The UV-vis spectra indicate that a 4-CO2Me substituent causes a red-shift in the frequency of the MLCT bands (330-365 nm), whereas the ligand field transitions appearing in the 380-420 nm region are influenced primarily by the P-substituents. Cyclic voltammetry measurements have shown that the oxidation potentials of the title complexes are affected by P- and ring-substituents, oxidation being somewhat easier with t-Bu2PO (vs i-Pr2PO), OMe and Me (vs CO2Me), and t-Bu (vs Cl). Moreover, oxidation potentials are affected more by the aromatic substituents at the 4-position vs those at the 3- and 5-positions.