Nanoporous gold functionalized macrocyclic metal complexes for highly efficientphotocatalytic oxidations

在本项目中，将大环金属络合物作为光敏剂固定在高比表面积的金属载体上，即纳米多孔金(NpAu)。这种新型材料组合在多相光催化领域具有广阔的应用前景。首次实验结果表明，与惰性氧化物载体相比，金属衬底对光催化活性有明显的增强作用。为此，树脂可能是这种金属载体材料独特的光学性质，并将在本研究项目中进一步研究。以下目标和工作包将是主要手段：a)制备不同结构尺寸(孔和韧带)的npAu底物。这种材料提供了微调毛孔和韧带大小的可能性，范围从大约30纳米一直到微米。这使得我们能够在光敏剂的高孔隙率和面积浓度与反应物的质量传输之间取得平衡。b)合成不同取代的大环金属络合物、金属酞菁(MPC)、亚酞菁(MsubPc)和甲基四苯基卟啉(MTPP)，它们可以以不同的吸收特性和几何形状键合在npAu底物上，作为研究敏化剂与底物相互作用的中心手段。C)将有机实体固定在npAu底物上：使用金属中心和底物之间具有不同间距的一步或两步合成程序(硫醇连接体和间隔体单元)。D)所制备的多相体系用于光氧化反应的催化研究：(I)不同体系产生单线态氧的效率(量子产率)的测定(Ii)考察该体系对不同(工业上重要的)光反应的氧化活性，香茅醇和苯酚的氧化。

In this project macrocyclic metal complexes as photosensitizer will be immobilized onto a high surface area metallic support, the nanoporous gold (npAu). This novel materials combination offers promising applications in the field of heterogeneous photocatalysis. First experimental results indicate an enhancing effect of the metallic substrate onto the photocatalytic activitiy, very much in contrast to inert oxidic supports. Resins for this might be unique optical properties of this metallic support material and will be further investigated in this research project.The following objectives and work packages will be central means:a) Preparation of npAu substrates with different structural sizes (pores and ligaments). This material provides the possibility to finely tune the pore and ligament size between about 30 nm all the way up to microns. This enables us to balance a high porosity and areal concentration of photosensitizer and the mass transport of reactants.b) Synthesis of differently substituted macrocyclic metal-complexes, metallo phthalocyanines (MPc), -subphthalocyanines (MsubPc), and ms-tetraphenylporphyrines (MTpp) which can be bonded onto the npAu substrate with different absorption characteristics and geometries as a central means of studying the interaction between sensitizer and substrate. c) Immobilization of organic entities onto the npAu substrate: Using one- or two-step synthetic procedures (thiol-linker and -spacer units) with different spacing between the metallic centre and the substrate. d) Catalytic investigation of the prepared heterogeneous systems for photooxidation reactions: (I) determination of the efficiency for generating singlet oxygen (quantum yield) for different systems (II) investigating the activity of the system for oxidation of different (industrially important) photoreactions, the oxidation of citronellol and phenol.