| 320345-22-0

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• CAS: 320345-22-0
• 化学式: C₇H₁₆N₄O₄Re*Cl*H₂O
• 分子量: 459.904
• InChiKey: FQLFSIDKGWOKPY-UHFFFAOYSA-K

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

• 作为产物：
  描述：

  盐酸 、 [ReOCl3(OPPh3)(SMe2)] 、 N,N'-bis(2-aminoethyl)malonamide 、 水 在 triethylamine 作用下， 以 乙醇 、 水 为溶剂， 以39%的产率得到
  参考文献：
  名称：

  Re(V) Complexes with an Open-Chain Quadridentate Ligand Containing Two Amine and Two Amido Donors. Synthesis, Characterization, and Solution Equilibria of Re₂O₃(dioxo-tetH₄)₂ and [ReO(H₂O)(dioxo-tetH₄)]Cl (dioxo-tetH₆ = 1,4,8,11-tetraazaundecane-5,7-dione)

  摘要：

  We are interested in identifying mononuclear cationic [M(V)=O](3+) (M = Tc, Re) complexes for radiopharmaceutical applications. The open-chain ligand, 1,4,8,11-tetraazaundecane-5,7-dione (dioxo-tetH(6)) with two amine and two amide donors, was selected for investigation since the literature led us to expect that a five-coordinate [Re(V)=O(dioxo-tetH(4))](+) cation would dominate. Instead, the neutral mu -oxo bridged dinuclear complex, Re2O3-(dioxo-tetH(4)](2) (1), and a salt of the six-coordinate mononuclear cation, [ReO(H2O)(dioxo-tetH(4))](+) (2), were isolated; the structure of each was determined by X-ray crystallography. The cation (2) is unusual because it has a trans-oxo/aqua core. Such aqua compounds are rarely isolated, and the Re-OH2 distance is relatively short (2.185 Angstrom). The cation has two pK(a) values, 4.1 and 8.7, determined with visible spectroscopy. Since the Re-OH2 bond is short, the coordinated water is likely to be acidic. Thus the two pK(a)'s are assigned to the stepwise deprotonation of the water ligand to give a trans-oxo/hydroxo neutral form and a trans-dioxo anion. Although 1 was the first product isolated following ligand exchange of ReOCl3(Me2S)(OPPh3) with dioxo-tetH(6) under neutral conditions, it probably formed from the hydroxo mononuclear complex. Under concentrated conditions (similar to 300 mM) the dinuclear complex deposited from solution, but the H-1 NMR spectra of 2 (similar to 20 mM) were consistent with the presence of only monomeric forms in D2O, pH 3-12. H-1 NMR experiments demonstrated that in DMSO-d(6) 2 converts to 1 upon addition of base, consistent with the proposal that two units of the hydroxo monomer condense to give the dinuclear form. In addition, all spectra of pure 1 dissolved in DMSO-d(6) included extra low intensity signals that were characteristic of the monomer. Thus, although 1 is favored over the neutral monomer in DMSO-d(6), the two complexes exist as a mixture of equilibrating forms. Our results do not support the previous findings for the Re(V) complex with a macrocyclic diamine-diamide ligand related to dioxo-tetH(6). The data indicate that the ability of an amido group to donate electron density to a Re(V) center is moderately greater than the donating ability of a neutral amine group.

  DOI：

  10.1021/ic000173p