Donzello Maria Pia, Viola Elisa, Ercolani Claudio, Fu Zhen, Futur David, Kadish Karl M
Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" , P.le A. Moro 5, I-00185 Roma, Italy.
Inorg Chem. 2012 Nov 19;51(22):12548-59. doi: 10.1021/ic301989a. Epub 2012 Nov 2.
Heteropentanuclear porphyrazines having the formula [(PtCl2)4LM] where L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato dianion and M = Zn(II), Mg(II)(H2O), Pd(II), Cu(II) or Co(II) were characterized by elemental analyses, IR-UV-visible spectroscopy and electrochemistry and the data compared to new and previously published results for the corresponding homopentanuclear compound [(PtCl2)4LPt]. This latter species has four external N2(py)PtCl2 coordination sites which closely resemble cis-platin, (NH3)2PtCl2, the potent chemotherapeutic anticancer drug, and is able to act as a photosensitizer for the generation of (1)O2, the cytotoxic agent in photodynamic therapy (PDT). UV-visible spectra and half wave potentials for reduction of [(PtCl2)4LM], [(PtCl2)4LPt], the parallel series of mononuclear [LM] compounds and the pentanuclear [(PdCl2)4LM] compounds were examined in the nonaqueous solvents dimethyl sulfoxide, pyridine, and dimethylformamide. The complete set of available data indicate that external coordination of the PtCl2 and PdCl2 units significantly increases the level of the electron-deficiency of the entire molecular framework despite the fact that these groups are far away from the central porphyrazine π-ring system and have coordination sites nearly orthogonal to the plane of the macrocycle. The pentanuclear species [(M'Cl2)4LM] (M' = Pt(II), Pd(II)) undergo multiple one-electron transfers and exhibit an easier reducibility as compared to related electrode reactions of the parent compounds [LM] having the same central metal. Aggregation phenomena and reducibility of the porphyrazines to their monoanionic form (prevalently in DMF) are observed for some of the examined compounds and were analyzed and accurately taken into account. Quantum yields of (1)O2 (ΦΔ), of interest in PDT, were measured for [(PtCl2)4LM] with M = Zn(II), Mg(II)(H2O), or Pd(II) and the related macrocycles [(PdCl2)4LM] and [LM] in dimethylformamide (DMF) and/or DMF preacidified with HCl (DMF/HCl, [HCl]: 1-2 × 10(-4) M). Excellent ΦΔ values (0.5-0.6) which qualify the compounds as potent photosensitizers in PDT were obtained for the pentanuclear species having Zn(II) or Pd(II) as central metal ions. The [(PtCl2)4LZn] and [(PtCl2)4LPd] complexes are of special interest as potential bimodal anticancer agents because of the incorporated four cis-platin-like functionalities.
通式为[(PtCl2)4LM]的异戊核卟啉嗪，其中L = 四 - 2,3 - [5,6 - 二(2 - 吡啶基)吡嗪并]卟啉二价阴离子，M = Zn(II)、Mg(II)(H2O)、Pd(II)、Cu(II)或Co(II)，通过元素分析、红外 - 紫外 - 可见光谱和电化学进行了表征，并将数据与相应的同戊核化合物[(PtCl2)4LPt]的新结果和先前发表的结果进行了比较。后一种物质有四个外部N2(py)PtCl2配位位点与顺铂（(NH3)2PtCl2，一种有效的化疗抗癌药物）非常相似，并且能够作为产生单线态氧（1O2，光动力疗法（PDT）中的细胞毒性剂）的光敏剂。在非水溶剂二甲基亚砜、吡啶和二甲基甲酰胺中研究了[(PtCl2)4LM]、[(PtCl2)4LPt]、单核[LM]化合物的平行系列以及戊核[(PdCl2)4LM]化合物的紫外 - 可见光谱和还原半波电位。完整的可用数据表明，尽管PtCl2和PdCl2单元远离中心卟啉嗪π - 环系统且配位位点几乎与大环平面正交，但它们的外部配位显著提高了整个分子框架的缺电子水平。与具有相同中心金属的母体化合物[LM]的相关电极反应相比，戊核物种[(M'Cl2)4LM]（M' = Pt(II)、Pd(II)）经历多次单电子转移并表现出更容易的还原性。对于一些所研究的化合物，观察到了卟啉嗪聚集体现象及其还原为单阴离子形式（主要在DMF中），并进行了分析和准确考虑。在二甲基甲酰胺（DMF）和/或用HCl预酸化的DMF（DMF/HCl，[HCl]：1 - 2×10(-4) M）中，测量了M = Zn(II)、Mg(II)(H2O)或Pd(II)的[(PtCl2)4LM]以及相关大环[(PdCl2)4LM]和[LM]的单线态氧（1O2）量子产率（ΦΔ），这在PDT中是令人感兴趣的。对于以Zn(II)或Pd(II)作为中心金属离子的戊核物种，获得了优异的ΦΔ值（0.5 - 0.6），这使这些化合物成为PDT中的有效光敏剂。[(PtCl2)4LZn]和[(PtCl2)4LPd]配合物作为潜在的双功能抗癌剂特别受关注，因为它们含有四个类似顺铂的官能团。
