利用钴-氨基硫脲类配合物作为氧化还原催化剂光分解水制备氢气

通过将磷配体与氨基硫脲结合进一步增加螯合配体的配位能力,并引入磺酸根增强其水溶性,合成了一个钴配合物Co-NSP(配体HNSP:4-2-(2-二苯基膦-苯烯基)-氨基硫脲腙]苯甲酸),利用其氧化还原特性开展均相体系的光驱动从水中制备氢气的研究。新的NSP三齿配体能够稳定低价的金属中心,有助于提升催化剂的催化性能。利用其与荧光素所构筑的光催化体系,在电子牺牲剂三乙胺存在下显示出良好的性能,光照6h其TON(turnover number)可达2000molH₂每摩尔催化剂。为了研究和比较其性能特点,对这一光催化体系的荧光滴定和氧化还原性能也进行了较细致的研究。

Photocatalytic Hydrogen Production from Water Using Cobalt-Thiosemicarbazone Complex as Redox Catalyst

By incorporating a phosphine donor within a thiosemicarbazone moiety to enhance the coordinated ability of the chelators, a cobalt complex Co-NSP (HNSP: 4-2-(2-diphenylphosphino-benzylidene) thiosemicar-bohydrazone]benzenesulfonate) was obtained as the proton reduction catalyst for light driven H₂ evolution in homogeneous environment with fluorescein as the photosensitizer. The presence of NSP tridentate chelator benefits the formation of low oxidized species to increase the catalytic efficiency, and the incorporation of a sulfonate group enhances the water solubility of the catalyst. The amount of H₂ generation in 12 h photolysis maximizes in the presence of sacrificial reagent NEt₃ at pHvalue of 11.0. The initial TOF (turnover frequency) is about 200 mol H₂ per mole catalyst per hour with the turnover number (TON) about 2000 mol H₂ per mole of catalyst.