The adsorption of the herbicide dimepiperate S-(alpha,alpha-dimethylbenzyl)-1-piperidinecarbothioate on homoionic Fe3+-, Al3+-, Ca2+-, and Na+-montmorillonite was studied in aqueous medium. The adsorption is described well by the Freundlich equation. The adsorption capacity decreases in the order Fe3+ > Al3+ > Ca2+ > Na+ 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 Al3+ and Fe3+ 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.
DIMEPIPERATE ADSORPTION AND HYDROLYSIS ON AL3+-MONTMORILLONITE, FE3+-MONTMORILLONITE, CA2+-MONTMORILLONITE, AND NA+-MONTMORILLONITE / Pusino, Alba; Liu, W; Gessa, C.. - In: CLAYS AND CLAY MINERALS. - ISSN 0009-8604. - 41:3(1993), pp. 335-340. [10.1346/CCMN.1993.0410308]
DIMEPIPERATE ADSORPTION AND HYDROLYSIS ON AL3+-MONTMORILLONITE, FE3+-MONTMORILLONITE, CA2+-MONTMORILLONITE, AND NA+-MONTMORILLONITE
PUSINO, Alba;
1993-01-01
Abstract
The adsorption of the herbicide dimepiperate S-(alpha,alpha-dimethylbenzyl)-1-piperidinecarbothioate on homoionic Fe3+-, Al3+-, Ca2+-, and Na+-montmorillonite was studied in aqueous medium. The adsorption is described well by the Freundlich equation. The adsorption capacity decreases in the order Fe3+ > Al3+ > Ca2+ > Na+ 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 Al3+ and Fe3+ 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.