Electrochemical evidence of host–guest interactions. Changes in the redox mechanism of fungicides iprodione and procymidone in the nano-cavity of cyclodextrins

• Published in: Microchemical journal Vol. 73; no. 1; pp. 213 - 219
• Main Authors: Hromadová, M, Pospı́šil, L, Giannarelli, S, Fuoco, R, Colombini, M.P
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier B.V 01-10-2002; Elsevier
• Subjects: Chemistry; Cyclodextrin; Electrochemistry; Exact sciences and technology; Fungicide; General and physical chemistry; Kinetics and mechanism of reactions; Redox reaction; Cyclodextrin; Fungicide; Redox reaction; Imidazole derivatives; Five membered ring; Nitrogen heterocycle; Pesticides; Oligoholoside; NMR spectrometry; Experimental study; Chemical reduction; Organic solvent; Methyl sulfoxide; Bicyclic compound; Reaction mechanism; Carboxamide; Inclusion compound; Electrochemical reaction; Ultraviolet visible spectrometry
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/S0026-265X(02)00066-8

The reduction mechanism of two pesticides, iprodione [3-(3,5-dichlorophenyl)-
N-(1-methylethyl)-2,4-dioxo-1-imidazolidinecarboxamide] and procymidone [3-(3,5-dichlorophenyl)-1,5-dimethyl-3-azabicyclo[3.1.0]hexane-2,4-dione], was studied in the absence and presence of β-cyclodextrin in a dimethylsulfoxide solvent. Distribution of the reduction products changed in the presence of β-cyclodextrin. The complex formation led to protection of the imidazolidine ring of iprodione against cleavage, with a subsequent decrease in aniline-type products. In the case of procymidone, the mechanism exclusively led to the formation of monochloro derivatives of the original pesticide. Host–guest-type interactions of these pesticides with cyclodextrin nano-cavities was unambiguously demonstrated by voltammetric measurements that were more sensitive than conventional spectroscopic methods, such as UV-VIS and NMR.