0000000000362312

AUTHOR

Kristı̄ne Babre

showing 2 related works from this author

Humic substances as catalysts in condensation reactions

2001

Humic substances (HS) demonstrate appreciable impact on the rate of the condensation reactions as shown in the example of the reaction between hydrazine and 4-(dimethylamino)-benzaldhyde in an aquatic environment. The catalytic activity of HS has also been demonstrated in Knoevenagel and Claisen-Schmidt reactions for condensation of carbonyl compounds with CH acids. The aquatic fulvic acids are the most active in these reactions. The velocity of the studied reactions also depends on pH, temperature, the concentration and origin of HS used. A possible micellar and acid-base catalysis mechanism in aquatic media has been suggested.

Environmental EngineeringChemical PhenomenaHealth Toxicology and MutagenesisHydrazineInorganic chemistryAldehydeCatalysisCatalysischemistry.chemical_compoundEnvironmental ChemistryOrganic chemistryHumic acidBenzopyransHumic Substanceschemistry.chemical_classificationClaisen condensationChemistry PhysicalCondensationTemperaturePublic Health Environmental and Occupational HealthGeneral MedicineGeneral ChemistryHydrogen-Ion ConcentrationCondensation reactionPollutionchemistryKnoevenagel condensationWater Pollutants ChemicalChemosphere
researchProduct

Decarboxylation and alkaline colour fading reactions in presence of humic substances.

2002

Humic substances (HSs) can substantially influence velocity of reactions in the environment as shown on example of decarboxylation and alkaline colour (e.g., malachite green and crystal violet) fading reactions. In colour fading and decarboxylation reactions of 6-nitrobenzisoxazole-3-carboxylic acid HS act as inhibitors, but additions of surfactants change the pattern of reaction. The inhibitory activity of HSs much depends on their origin. The velocity of studied reactions depends also on pH, temperature and concentration of HS used. Possible micellar catalysis mechanism has been suggested.

Models MolecularReaction mechanismEnvironmental Engineeringgenetic structuresDecarboxylationHealth Toxicology and MutagenesisInorganic chemistryCarboxylic AcidsColorDecarboxylationCatalysisCatalysischemistry.chemical_compoundSurface-Active AgentsHydroxidesRosaniline DyesEnvironmental ChemistryHumic acidCrystal violetMalachite greenChemical decompositionHumic SubstancesMicelleschemistry.chemical_classificationPublic Health Environmental and Occupational HealthTemperatureGeneral MedicineGeneral ChemistryReaction inhibitorHydrogen-Ion ConcentrationPollutionKineticschemistryGentian VioletChemosphere
researchProduct