The electrochemistry of N-methyl-N′-heptyl-4,4′-bipyridinium (C1C7V2+) and N,N′-dibenzyl-4, 4′-bipyridinium (BBV2+) salts with α-cyclodextrin and β-cyclodextrin (CD) was studied. The cyclic voltammetric behavior of both viologens revealed a cyclodextrin-induced conproportionation reaction between the electrogenerated viologen neutral forms and viologen dications with β-CD, but not with the α form. Both α-CD and β-CD suppress dimerization of C1C7V2+, whereas only β-CD is effective for disruption of the BBV.+ dimer. These results are interpreted in terms of the involvement of the bipyridine ring and benzyl group, depending on the oxidation state of viologen, in the inclusion complexation with β-CD, but not significantly with α-CD.
Bibliographical noteFunding Information:
The support of this researchb y the Korea Science and EngineeringF oundation (931-0300-018-2a)n d the Ministry of Educationo f the Republic of Korea through the Basic Science Research Institute Program (BSRI-92-335)is gratefullya cknowledged.