[(CO)5MnRe(CO)3(2,3-bis(2-pyridyl)pyrazine)] | 167277-30-7

• 英文名称: [(CO)5MnRe(CO)3(2,3-bis(2-pyridyl)pyrazine)]
• CAS: 167277-30-7
• 化学式: C₂₂H₁₀MnN₄O₈Re
• 分子量: 699.488
• InChiKey: NXDWZOUHAIMJJI-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
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• 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：

  [(CO)5MnRe(CO)3(2,3-bis(2-pyridyl)pyrazine)] 、 fac-bis(acetonitrile)bromotricarbonylrhenium(I) 以 四氢呋喃 为溶剂， 生成 [(CO)5MnRe(CO)3(2,3-bis(2-pyridyl)pyrazine)Re(Br)(CO)3]
  参考文献：
  名称：

  Synthesis and Characterization of New Dinuclear Complexes (CO)5MnRe(CO)3(L) (L = 2,2'-Bipyrimidine, 2,3-Bis(2-pyridyl)pyrazine) and Trinuclear Compounds (CO)5MnRe(CO)3(L)R (R = Re(Br)(CO)3, W(CO)4). Evidence for Asymmetric Distortion of the Bridging 2,2'-Bipyrimidine Ligand (L) in (CO)5MnRe(CO)3(L)Re(Br)(CO)3 from the Crystal Structure and 1H-NMR and Resonance Raman Spectra

  摘要：

  This article describes the synthesis and spectroscopic (H-1-NMR, UV/vis, resonance Raman) properties of the new complexes (CO)(5)MnRe(CO)(3)(L), (CO)(5)MnRe(CO)(3)(L)Re(Br)(CO)(3) (L = 2,2'-bipyrimidine (BPYM), 2,3-bis(2-pyridyl)pyrazine (DPP)), and (CO)(5)MnRe(CO)(3)(BPYM)W(CO)(4) and the single-crystal X-ray structure of (CO)(5)MnRe(CO)(3)(BPYM)Re(Br)(CO)(3). The crystals are triclinic, space group P $($) over bar$$ 1, with cell dimensions a = 11.819(3) Angstrom, b = 14.957(9) Angstrom, c = 15.792(7) Angstrom, alpha = 64.09(4)degrees, beta = 88.88(7)degrees, gamma = 88.22(8)degrees, and Z = 4. Least-squares refinement on F, for 4620 observed reflections, converged to R = 0.127. The two different metal fragments (CO)(5)MnRe(CO)(3) and Re(Br)(CO)(3) are coordinated to BPYM via Re with Mn(CO)(5) and Br- in a mutually trans position perpendicular to the BPYM plane. An important aspect of this structure is the asymmetric bonding within the bridging BPYM ligand. From the C-N bonds connected to the inter-ring C-C bond, those involving N atoms coordinated to the Re-0 atom of the (CO)(5)MnRe(CO)(3) moiety are longer than those involving the N atoms coordinated to the Re-1 atom of the Re(Br)(CO)(3) fragment. This asymmetry of BPYM is also evident from the H-1-NMR spectrum and is responsible for the occurrence of two absorption bands in the visible region belonging to separate transitions from the two metal fragments to BPYM. It even manifests itself in the resonance Raman spectra by showing resonance enhancement of intensity for BPYM vibrations with slightly different frequencies upon excitation into either of these MLCT bands. This asymmetry is not observed for the corresponding DPP-bridged complex and also not for (CO)(5)MnRe(CO)(3)(BPYM)W(CO)(4). The resonance Raman spectra of the latter compound point to a reversal of the order of the a(u) and b(2u) pi* orbitals of BPYM as compared with the free ligand. The distortion of the BPYM ligand appears to be responsible for a very weak electronic pi interaction between the two metal fragments in (CO)(5)MnRe(CO)(3)(BPYM)Re(Br)(CO)(3) which may thus be viewed as a mixed-valence complex.

  DOI：

  10.1021/ic00123a007

文献信息

• Photochemistry and Emission of the Dinuclear Complexes (CO)5MnRe(CO)3(L) (L = 2,2'-Bipyrimidine, 2,3-Bis(2-pyridyl)pyrazine) and Bridged Trinuclear Complexes (CO)5MnRe(CO)3(L)Re(Br)(CO)3 and (CO)5MnRe(CO)3(BPYM)W(CO)4: Effect of the Remote Metal Center on the Photodissociation of the Mn-Re Bond
  作者：J. W. M. van Outersterp、D. J. Stufkens、A. Vlcek

  DOI：10.1021/ic00125a016

  日期：1995.10

  Photochemical and emission properties of the dinuclear (CO)(5)MnRe(CO)(3)(L) and trinuclear (CO)(5)MnRe(CO)(3)(L)Re(Br)(CO)(3) and (CO)(5)MnRe(CO)(3)(BPYM)W(CO)(4) complexes (L = 2,2'-bipyrimidine (BPYM), 2,3-bis(2-pyridyl)pyrazine (DPP)) are described. All these compounds undergo photochemical homolysis of the Mn-Re bond upon excitation into their MLCT absorption band(s) in the visible spectral region. Mn(Cl)(CO)(5) and Re(Cl)(CO)(3)(L) or Re(Cl)(CO)(3)(L)Re(Br)(CO)(3) are formed in chlorinated solvents (CH2Cl2, CCl4) from the former two types of complexes, respectively. In THF, photolysis produces Mn-2(CO)(10), together with [Re(CO)(3)(L)](.), [Re(CO)(3)(L)Re(Br)(CO)(3)](.), or [Re(CO)(3)(BPYM)W(CO)(4)](.) radicals, respectively, which presumably contain also a coordinated THF molecule. Photoreactions of the dinuclear complexes occur with high quantum yields (0.36 for BPYM and 0.54 for DPP), which are independent of the temperature and of the excitation wavelength. The attachment of the Re(Br)(CO)(3) group to the potentially bridging ligand L in (CO)(5)MnRe(CO)(3)(L) to form the L-bridged trinuclear species strongly influences the excited state dynamics involved in the photochemistry. Thus, the photochemical quantum yields of the trinuclear complexes are both temperature and excitation wavelength dependent. The apparent activation energy, together with the overall quantum yield, decreases upon changing the excitation from the high- to the low-energy MLCT absorption band. The Mn-Re bond homolysis is about 6 times more efficient for bridging DPP than for bridging BPYM. The dinuclear complexes exhibit, in a 2-MeTHF glass at 80 K, an emission from thermally unequilibrated states, whereas double emission, extending into the near-IR spectral region, was observed for (CO)(2)MnRe(CO)(3)(DPP)Re(Br)(CO)(3). Its BPYM analogue is nonemissive. To account for this complex photobehavior, an excited state diagram and a qualitative dynamics model are proposed. The reaction is assumed to occur from a 3 sigma pi* state that is nonradiatively populated from the higher MLCT state(s). The main effects of the attachment of the Re(Br)(CO)(3) group, which is responsible for the changed photochemical behavior, are the profound stabilization of the pi* LUMO of the bridging ligand L and the introduction of another MLCT excited state into the trinuclear molecule.