Department of Mandatory Lessons, Division of Chemistry, Gulhane Medical Academy, (GATA), 06018, Etlik, Ankara, Turkey.
Dalton Trans. 2010 Nov 7;39(41):9801-14. doi: 10.1039/c0dt00641f. Epub 2010 Sep 17.
The phthalodinitrile derivative 3 was prepared by the reaction of 1,4-dithioerythritol 1 and 4-nitrophthalonitrile 2 in dry DMF as the solvent in the presence of K(2)CO(3) as the base by the method of nucleophilic substitution of an activated nitro group in an aromatic ring. The template reaction of compound 3 with the corresponding metal salts gave the novel binuclear MPcs of ball-type (M = Zn 4, Co 5, Cu 6) and their water soluble phthalocyanines 7-9 were obtained from refluxing a suspension of the compounds bearing eight OH side groups, in aqueous NaOH (%30) solution. Newly synthesized compounds were characterized by elemental analysis, UV/VIS, IR, MALDI TOF mass and (1)H-NMR spectroscopy techniques. The electronic spectra exhibit an intense π→π* transition of characteristic Q and B bands of the phthalocyanine core. The electrochemical measurements showed the formation of various mixed-valence oxidation and reduction species of 4 and 6 due to weak intramolecular interactions between the two MPc units. Complex 5 displayed a much higher catalytic activity than those of 4 and 6. It was found that oxygen reduction on the 5-based catalyst occurs through a direct 4-electron transfer pathway with a high water selectivity. However, the overpotential for oxygen reduction is high, probably due to a long distance between the two CoPc units in 5. A.c. and d.c. conductivity measurements were performed as a function of temperature (300-543 K) and frequency (40-10(5) Hz). It was found from d.c. measurements that the values of the pre-exponential factor σ(0) for the investigated samples are in the interval from 1.36 × 10(-3) to 6.20 × 10(2)Ω(-1) cm(-1), inferring that the conduction occurs most probably by hopping between the localized states in band tails. Based on the existing theory of a.c. conduction, it has been concluded that for the low frequency region the dominant conduction mechanism is multihopping at high temperatures (>390 K) whereas for the high frequency region the correlated barrier hopping model is the dominant mechanism. The sensing properties of the films for CO(2) gas were also investigated.
1,4-二硫代赤藓糖醇 1 和 4-硝基邻苯二甲腈 2 在干燥 DMF 中反应，在 K(2)CO(3)作为碱的存在下，通过芳环中活化硝基的亲核取代反应制备了邻苯二甲腈衍生物 3。化合物 3 与相应金属盐的模板反应得到了新型双核 MPc 的球型（M = Zn 4、Co 5、Cu 6），并通过回流含有八个 OH 侧基的化合物在水性 NaOH（30%）溶液中得到了它们的水溶性酞菁 7-9。新合成的化合物通过元素分析、UV/VIS、IR、MALDI TOF 质谱和（1）H-NMR 光谱技术进行了表征。电子光谱显示出酞菁核心特征 Q 和 B 带的强烈π→π*跃迁。电化学测量表明，由于两个 MPc 单元之间的弱分子内相互作用，4 和 6 形成了各种混合价态的氧化还原物种。与 4 和 6 相比，复合物 5 表现出更高的催化活性。发现基于 5 的催化剂上的氧还原通过具有高水选择性的直接 4 电子转移途径发生。然而，氧还原的过电位很高，可能是由于 5 中两个 CoPc 单元之间的距离较长。作为温度（300-543 K）和频率（40-10(5) Hz）的函数，进行了交流和直流电导率测量。从直流测量中发现，所研究样品的前指数因子 σ(0)的值在 1.36×10(-3)到 6.20×10(2)Ω(-1)cm(-1)之间，这表明传导最有可能通过带尾中的局域态之间的跳跃发生。基于交流传导的现有理论，可以得出结论，对于低频区域，在高温（>390 K）下主要的传导机制是多跳跃，而对于高频区域，相关势垒跳跃模型是主要的机制。还研究了薄膜对 CO(2)气体的传感性能。
