Catalytic hydrolysis of quinalphos on homoionic clays

Pusino, Alba; Gessa, C.; Kozlowski, Henryk

doi:10.1002/ps.2780240102

Cited by 34 publications

(22 citation statements)

References 13 publications

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“…Because of their favourable physical and chemical properties, such as high surface area, large adsorption and ion-exchanging capacity, montmorillonites are widely employed as catalysts in the synthesis of fine chemicals and drugs under mild experimental conditions. [9][10][11][12][13][14][15][16][17] Remarkably, montmorillonites catalyze the aldol condensations of formaldehyde into sugars ("formose reaction"). [18,19] From these points of view montmorillonites can be considered as primitive enzymes.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Degradation of Nucleobases and Nucleic Acids by Formamide in the Presence of Montmorillonites

et al. 2004

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We describe the role of formamide, a product of the hydrolysis of hydrogen cyanide, as precursor of several components of nucleic acids under prebiotic conditions. When formamide is heated in the presence of montmorillonites, the efficient one-pot synthesis of purine, adenine, cytosine, and uracil is obtained. Along with these nucleobases, several components of the inosine pathway are obtained: 5-aminoimidazole-4-carboxamide, 5-formamidoimidazole-4-carboxamide and hypoxanthine. This almost complete catalogue of nucleic acid precursors is accompanied by N(9)-formylpurine, which, containing a masked glycosidic bond in its formyl moiety, is a plausible precursor of purine acyclonucleosides. In addition, montmorillonites differentially affect the rate of degradation of nucleobases when embedded in 2'-deoxyoligonucleotides; namely, montmorillonites protect adenine and guanine from the degradative action of formamide, while thymine degradation is enhanced. The oligonucleotide backbone reactivity to formamide is also affected; this shows that the interaction with montmorillonites modifies the rate of abstraction of the Halpha and Hbeta protons on the sugar moieties.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Degradation of Nucleobases and Nucleic Acids by Formamide in the Presence of Montmorillonites

et al. 2004

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“…One of them is derivatization of the herbicides into less harmful compounds after crop development while the other is the metal ion associated degradation or deactivation of the herbicides [5][6][7][8]. Studies have shown that metal ions can show remarkable effect in catalyzing the decomposition of herbicides [9][10].…”

Section: Introductionmentioning

confidence: 99%

<b>Studies on transition metal complexes of herbicidal compounds. II: Transition metal complexes of derivatized 2-chloro-4-ethylamino-6-isopropylamino-<i>s</i>-triazine (atrazine)</b>

Dinku

Megersa

Raju

et al. 2003

Bull. Chem. Soc. Eth.

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2(2-Hydroxyethyl)hydrazino-4-ethylamino-6-isopropylamino-s-triazine (HEATZ), a derivative of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, atrazine (ATZ)-a well known herbicide has been studied for complex formation with cobalt(II), nickel(II), and copper(II). Analytical, conductance, thermal, and spectral studies suggest that HEATZ is a monobasic NNO donor and it forms binuclear octahedral metal complexes, possessing alkoxide bridging. Cobalt(II) complex exhibits thermochromism. Antimicrobial studies on E. coli and S. aureus show the absence of growth inhibitory activities for HEATZ and its metal complexes which is attributed to the combined effect of derivatization of ATZ and metal complexation.

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“…Various reviews emphasize the role played by the clay surfaces in catalyzing the hydrolysis of organic pollutants (Ortego et al 1991;Kowalska et al 1994). The saturating cation is critical to the catalytic effect, since upon changing the nature of the cation associated with the clay, different hydrolysis rates and pathways are observed (Saltzman et al 1974;Pusino et al 1988;Pusino and Gessa 1990;Pusino et al 1993). Sulfonylureas are also strongly adsorbed (Ukrainczyk and Rashid 1995) and degraded on smectites (Pantani et al 1994).…”

Section: Introductionmentioning

confidence: 99%

Interaction of Rimsulfuron with Smectites

Calamai

Pantani

Pusino

et al. 1997

Clays and clay miner.

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Abstract--The adsorption of the sulfonylurea herbicide rimsulfuron, [N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-pyridinesulfonamide], on clay minerals with different saturating cations was studied. Three smectites with different lattice charge distribution (hectorite, montmorillonite and nontronite) were selected and made homoionic to Ca 2+, Cu 2+ and AP +. Because of the instability of rimsulfuron in water, the experiments were carried out in chloroform solution. The interaction mechanism depends on the nature of the saturating cation and the tetrahedral layer charge of the silicate. Among the exchangeable ions studied, only AP + is able to produce degradation of the herbicide to N-(4,6-dimethoxypyrimidin-2-yl)-N-[(3-(ethylsulfonyl)-2-pyridinyl]urea. In this case, the lower the tetrahedral charge, the more active the degradation. The Ca2+-saturated clays are ineffective in the degradation. In contrast, the formation of a stable chelate complex with the saturating ion permits rimsulfuron to be adsorbed to a rather high extent into Cu(II)-clays and to be stable against degradation.

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Catalytic hydrolysis of quinalphos on homoionic clays

Cited by 34 publications

References 13 publications

Synthesis and Degradation of Nucleobases and Nucleic Acids by Formamide in the Presence of Montmorillonites

Synthesis and Degradation of Nucleobases and Nucleic Acids by Formamide in the Presence of Montmorillonites

<b>Studies on transition metal complexes of herbicidal compounds. II: Transition metal complexes of derivatized 2-chloro-4-ethylamino-6-isopropylamino-<i>s</i>-triazine (atrazine)</b>

Interaction of Rimsulfuron with Smectites

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