6533b7dafe1ef96bd126eda0

RESEARCH PRODUCT

Humic substances as catalysts in condensation reactions

Māris KļaviņšKristı̄ne BabreJudı̄te Dipāne

subject

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 Chemical

description

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.

yearjournalcountryeditionlanguage
2001-08-03Chemosphere
https://doi.org/10.1016/s0045-6535(00)00294-0