Photoinduced Homolysis of Alkyl-Cobalt(III) Bonds in a Cyclodextrin Cage

作者：Imabeppu Kohei; Kuwano Hiroyuki; Yutani Eriko; Kitagishi Hiroaki; Kano Koji^*

来源：European Journal of Inorganic Chemistry, 2016, 2016(12): 1784-1789.

DOI：10.1002/ejic.201600208

• Cage effect
• Host-guest systems
• Cobalt
• Photochemistry
• Vitamins

Photodecomposition of methyl-and ethyl-Co-III complexes of meso-tetrakis(4-sulfonatophenyl) porphyrin (CH3- and C2H5-Co(III)TPPSs) was used as a reaction probe to study the cage effect of cyclodextrin capsules formed by two per-O-methylated beta-cyclodextrin (TMe-beta-CD) molecules and their covalently linked dimer, Ph2CD. The photodecomposition of CH3-(CoTPPS)-T-III under aerobic conditions was markedly suppressed in the presence of TMe-beta-CD and Ph2CD, while C2H5-(CoTPPS)-T-III was less affected. Alkyl-(CoTPPS)-T-III formed two types of inclusion complex with Ph2CD, the alkyl groups in Type 1 being located at the opposite side of the phenyl linker of Ph2CD and those in Type 2 being located at the same side. The photodecomposition of C2H5-(CoTPPS)-T-III in Type 1 proceeded via an ethylperoxo complex, while that in Type 2 occurred via a radical pair generated in a narrow, rigid cage to form ethylene and (CoTPPS)-T-II.

• 出版日期2016-4