[Study on supramolecular complexes of cyclodextrins and fenoxaprop-p-ethyl by UV spectra].
The supramolecular complexes of fenoxaprop-p-ethyl and various cyclodextrins (beta-CD, HP-beta-CD, RAMEB) were studied by UV spectra technique. The results showed that all cyclodextrins could form 1:1 inclusion complexes with fenoxaprop-p-ethyl in ethanol-water (the volume ratio of ethanol to water was 1 : 4), and the binding constants of the three types of cyclodextrins toward fenoxaprop-p-ethyl were in the order of KRAEB>>KHP-beta-CD>Kbeta-CD. Between 298. 15 and 318. 15 K, the binding constants decreased with temperature increasing. The Gibbs free energy deltaG, enthalpy change deltaH, and entropy change deltaS determined were all negative, suggesting that the inclusion complexation is exothermic and can spontaneously occur by the balance of enthalpy driving and entropy opposing.
Zhang
An-ping
AP
Institute of Environmental Science, Zhejiang University, Hangzhou 310029, China.
Luo
Fan
F
Liu
Wei-ping
WP
D003505:Cyclodextrins / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry*; D010080:Oxazoles / Q000737:chemistry*; D011422:Propionates / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D003505:Cyclodextrins; D009930:Organic Chemicals; D010080:Oxazoles; D011422:Propionates; C416661:fenoxaprop ethyl