Lu(II) texaphyrin complex radical anion | 221239-67-4

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: Lu(II) texaphyrin complex radical anion
• 英文别名: Lu-Tex(1+) radical
• CAS: 221239-67-4
• 化学式: C₄₈H₆₆LuN₅O₁₀
• 分子量: 1048.05
• InChiKey: ABYLNXZXIUEUBO-CWLLKONLSA-N

反应信息

• 作为产物：
  描述：

  Lu(III) texaphyrin complex 在 2,3,5-trimethyl-p-benzoquinone 作用下， 以 水 为溶剂， 生成 Lu(II) texaphyrin complex radical anion
  参考文献：
  名称：

  Pulse Radiolytic Studies of Metallotexaphyrins in the Presence of Oxygen:  Relevance of the Equilibrium with Superoxide Anion to the Mechanism of Action of the Radiation Sensitizer Motexafin Gadolinium (Gd−Tex²⁺, Xcytrin)

  摘要：

  Pulse radiolytic studies of aqueous solutions of four representative metallotexaphyrin complexes M-Tex(2+) (M = Gd(III), Lu(III), Dy(III), and Y(III)), carried out in the presence of either dioxygen, or trimethyl-p-benzoquinone (TMQ). It was found that all four of these M-Tex(2+) species set up an equilibrium with superoxide and the singly reduced TMQ (TMQ(.-)) on the pulse radiolytic time scale. Rate constants for the forward (k(1)) and back (k(-t)) reactions of Gd-Tex(2+) with superoxide anions, at pH 8.5, were determined to be (9.8 +/- 1.5) x 10(6) M-t s(-1) and (3.4 +/- 0.5) x 10(6) M-1 analogous rate constants were found to be (1.5 +/- 0.2) x 10(7) M-1 s(-1) and (3.7 +/- 0.6) x 10(6) M-1 s(-1) respectively. Equilibrium constants (K-kin,), calculated from these kinetic parameters, were found to be 2.9 and 4.1 for Gd-Tex(2+) reacting with O-2(.-) (to produce Gd-Tex(.+) and O-2) and TMQ(.-) (to produce Gd-Tex(.+) and TMQ), respectively. Equilibrium constants for the M-Tex(2+) species reacting with O-2(.-) and TMQ(.-) were also determined from analysis of the absorption following establishment of the equilibrium. The resulting values for Gd-Tex(2+) were found to be 6.8 and 10.7, respectively. From these equilibrium constants, the redox potential for the M-Tex(2+)/M-Tex(.+) couples at pH 8.5 were estimated and found to be ca. -110 mV vs s(-1) and (3.4 +/- 0.5) x 10(6) M-1 NHE in the case of Gd-Tex'S s(-1), respectively. From these equilibrium constants, the redox potential for the M-Tex(2+)/M-Tex(.+) couples at pH 8.5 were estimated and found to ba ca. -110 mV vs NHE in the case of Gd-Tex(2+).

  DOI：

  10.1021/jp0035131

文献信息

• One-Electron Reduction and Oxidation Studies of the Radiation Sensitizer Gadolinium(III) Texaphyrin (PCI-0120) and Other Water Soluble Metallotexaphyrins
  作者：Jonathan L. Sessler、Nicolai A. Tvermoes、Dirk M. Guldi、Tarak D. Mody、William E. Allen

  DOI：10.1021/jp9838588

  日期：1999.2.1

  The radiation sensitizer gadolinium(III) texaphyrin 2 (XYTRIN; PCI-0120; Gd-Tex(2+)) and several other water soluble metallotexaphyrin complexes were prepared and studied using pulse radiolysis. All of the metallotexaphyrins were found to react with solvated electrons and hydroxyl radicals, yielding the corresponding one-electron reduced and oxidized metallotexaphyrins, respectively. The rates of the reduction processes range from 3.7 x 10(10) to 6.8 x 10(10) M-1 s(-1) (+/-10%), while those involving oxidation range from 2.5 x 10(9) to 7.4 x 10(9) M-1 s(-1) (+/-10%). The spectral characteristics of the transformed metallotexaphyrins produced by these reactions, e.g., a broad absorption band with a lambda(max) centered around 830 nm, are consistent with ligand-centered redox processes. Reaction of the metallotexaphyrins with solvated electrons affords species which exhibit metal dependent behavior. In the absence of hydroxyl radicals, the decay of the reduced metallotexaphyrins produced by reaction with electrons involves an initial protonation event followed by either a dimerization process or a disproportionation step. These latter transformations are followed by a second protonation event.