Dimepiperate adsorption and hydrolysis on Al (super 3+) -, Fe (super 3+) -, Ca (super 2+) -, and Na (super +) -montmorillonite
Dimepiperate adsorption and hydrolysis on Al (super 3+) -, Fe (super 3+) -, Ca (super 2+) -, and Na (super +) -montmorillonite
Clays and Clay Minerals (June 1993) 41 (3): 335-340
- adsorption
- alkali metals
- alkaline earth metals
- aluminum
- calcium
- cation exchange capacity
- chemical properties
- clay mineralogy
- clay minerals
- experimental studies
- hydrolysis
- infrared spectra
- iron
- metals
- montmorillonite
- pesticides
- sheet silicates
- silicates
- sodium
- spectra
- X-ray diffraction data
- dimepiperate
The adsorption of the herbicide dimepiperate S-(alpha ,alpha -dimethylbenzyl)-1-piperidinecarbothioate on homoionic Fe (super 3+) -, Al (super 3+) -, Ca (super 2+) -, and Na (super +) -montmorillonite was studied in aqueous medium. The adsorption is described well by the Freundlich equation. The adsorption capacity decreases in the order Fe (super 3+) > Al (super 3+) > Ca (super 2+) > Na (super +) clay. The dimepiperate adsorption from chloroform solution was also investigated by analytical, spectroscopic, and X-ray powder diffraction techniques. IR results suggest that the adsorption involves the interaction of the thioester carbonyl group of dimepiperate possibly with the surrounding water of metal ions. On Al (super 3+) and Fe (super 3+) clays, this interaction leads to hydrolysis of the thioester bond and formation of the thiol and carbamic acid derivatives that yield alpha -methylstyrene and piperidine, respectively.