Malonic acid is considered one of the most abundant dicarboxylic acids present in the atmosphere. Thermal decomposition of this acid produce the acetic acid and CO2 gas that represent a specie highly contaminant for the air. In this work, the thermal decomposition reaction in the gas phase of the malonic acid was evaluated using quantum-chemical calculations at the B3LYP/6-31+G(d,p) level. The Nudged Elastic Band (NEB) method has been used to find the saddle points that correspond to the transition states.These transition states were characterized using the electron localization function (ELF) topological analysis of the electronic density. For the molecular strucutre TS1 and TS2, energetic barriers were equal to 26.9 kcal/mol and 68.6 kcal/mol, respectively. These results are consistent with the reported in other investigations

Computational Theoretical study of reaction path of the unimolecular decomposition of malonic acid in the gas phase using the neb method

The pesticide Diazinon (DZN) is a toxic compound of the class of organophosphates (OF’s) used as an acaricide and fungicide. Its half-life (t1/2) is greater than 17 months (60 ºC). In this context, Imidazole (IMZ) stands out as a powerful nucleophile/catalyst in OF's dephosphorylation reactions. For the reaction of DZN with IMZ in the pH range 3-10, catalytic increments of 1000 times and t1/2 less than 3 h were obtained, with the ionic form of IMZ being the most reactive. Nuclear Magnetic Resonance Analysis - 31P NMR Indicates that the reaction at pH 5 (with an ionic species from IMZ - pKa ~ 7) leads to the formation of one phosphorylated product, suggesting that IMZ acts as general acid catalyst helping water nuleophilic attack on phosphorus. At pH 8, IMZ becomes promiscuous, leading to the formation of 3 phosphorylated products, suggesting that IMZ acts as: i) nucleophile in the aliphatic carbon of DZN, forming a diester derived from DZN and ii) general basic catalyst, helping the water attack on the phosphorus of DZN and the diester formed in i). Even though promiscuous, IMZ acts in an incredibly versatile way in reactions with DZN, exercising multiple catalysis and modulating the mechanisms according to pH, outlining new possibilities for detoxification and monitoring.

Dephosphorylation reactions of organophosphate pesticide diazinon with imidazole: kinetics and mechanistic insights

Recently, FDA approved the use of Rufinamide as a new anti-epileptic drug, the first and only triazole derivative for this medical treatment. This is a relatively new drug, it is understood that chemistry (synthesis) and biology (pharmacology-pharmacovigilance) of this compound is currently new. In order to delve into the understanding of the chemistry of said compound, for this work, the obtaining of Rufinamide analogues was carried out, applying as a synthetic strategy cycloaddition (3 + 2) azide-enolate. Reactions were under mild conditions and subsequent hydrolysis. With good yields.

Síntesis de nuevos análogos de la Rufinamida vía cicloadiciones (3+2) azida–enolato

The use of magenta cherry juice is proposed as an indicator of the pH change in standardizations and acid-base titrations.

Syzygium paniculatum juice as an indicator in acid-base titration. A low-cost alternative to teaching the pH concept

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