修饰NADH模拟物的金属-有机三元环光催化制氢

将含有不同还原型烟酰烟腺嘌呤二核苷酸(NADH)活性中心模拟物的有机配体H2L1和H2L2与钴离子配位自组装获得2例具有氧化还原活性且带有正电荷的金属-有机大环Co-L1和Co-L2.选择阴离子型钌基光敏剂[Ru(dcbpy)3]4-(dcbpy=2,2'-联吡啶-4,4'-二羧酸)作为光敏中心,金属-有机大环结构作为...

Metal-Organic Triangles with NADH Mimics for Photocatalytic Hydrogen Production

By incorporating two different reduced nicotinamide adenine dinucleotide(NADH)mimics within the ligand backbone,two positively charged cobalt-based metal-organic triangular hosts Co-L¹and Co-L²(H₂L¹-5′-(benzo[d]thiazol-2-yl)-N⁴,N^{′′′′′4"}-bis((E)-pyridin-2-ylmethylene)-[1,1′:3′,1"-terphenyl]-4,4"-dicarbohydrazide,H₂L²=5′-(benzo[d]imidazol-2-yl)-N^′4,N^{′′′′′4"}-bis((E)-pyridin-2-ylmethylene)-[1,1′:3′,1"-terphenyl]-4,4"-dicar bohydrazide)have been prepared in high yield and characterized as a redox vehicle for the construction of an artificial photosynthesis(AP)system.By taking advantage of electrostatic interaction to facilitate the formation of host-guest complexes,anionic ruthenium-based photosensitizer[Ru(dcbpy)₃]^4-(dcbpy=2,2′-bipyridine-4,4′-dicarboxylic acid)was encapsulated into the suitable cavity of hosts to improve photoinduced electron transfer(PET)processes and to promote photocatalytic hydrogen production.Compared with metal-organic triangular Co-L³without NADH mimics(H₂L³=5′-methyl-N^′4,N^{′′′′′4"}-bis((E)-pyridin-2-ylmethylene)-[1,1′:3′,1"-terphenyl]-4,4"-dicarbohydrazide)and mononuclear catalyst Co-L⁴(HL⁴=(E)-N′-(pyridin-2-ylmethylene)benzohydrazide)containing the same coordination environment and without NADH mimics,photocatalytic hydrogen production efficiency of the host-guest supramolecular photosynthetic systems could increase 1.6 and 6 times,respectively.The higher catalytic activity is attributed to the formation of host-guest complex between catalyst Co-L¹and Co-L²and photosensitizer[Ru(dcbpy)₃]^4-and the introduction of NADH mimics benefiting the PET process between the catalyst and photosensitizer.