1124-31-8Relevant articles and documents
Identification of products in the reaction of 2-[(hydroxyimino)methyl]-1,3-dimethylimidazolium iodide with diethyl 4-nitrophenyl phosphate in alkaline medium
Kapitanov,Abakumov,Serdyuk
, p. 1368 - 1375 (2015)
Products of the reaction of 2-[(hydroxyimino)methyl]-1,3-dimethylimidazolium iodide with diethyl 4-nitrophenyl phosphate in alkaline medium have been identified by electronic spectroscopy, one-(1H, 31P, 13C) and two-dimensional (1H-1H COSY, 1H-31P HMBC) NMR techniques, and NMR titration. 2-[(Hydroxyimino)-methyl]-1,3-dimethylimidazolium iodide has been found to act as nucleophile which is likely to be converted into 2-cyano-1,3-dimethylimidazolium. The other products are 4-nitrophenol and diethyl hydrogen phosphate. Other reaction paths, such as nucleophilic catalysis of the hydrolysis of diethyl 4-nitrophenyl phosphate by 2-[(hydroxyimino)methyl]-1,3-dimethylimidazolium iodide and formation of a stable phosphorylated product, have been ruled out.
Significant and differential acceleration of dephosphorylation of the insecticides, paraoxon and parathion, caused by alkali metal ethoxides.
Um, Ik-Hwan,Jeon, Sang-Eun,Baek, Mi-Hwa,Park, Hye-Ran
, p. 3016 - 3017 (2003)
In the reaction of paraoxon with alkali metal ethoxides, ion-paired EtO-M+ species are more reactive than the dissociated EtO- with the reactivity order EtO-Li+ EtO-Na+ > EtO-K+ > EtO-, while in the reaction of parathion, the reactivity follows the order
Catalytic nanoreactors for ester hydrolysis
Berlamino, Alexanders T.N.,Orth, Elisa S.,Mello, Renata S.,Medeiros, Michelle,Nome, Faruk
, p. 7 - 12 (2010)
Hydrolysis of 4-nitrophenyl benzoate (PNPB) in the presence of ionene nanoreactors was studied comparing the ionenes, poly[(dimethyl)-2-hydroxy propanodiyl chloride] (2-OH-33R1), poly[(methylbutyliminium)-2-hydroxy propanodiyl chloride] (2-OH-33R4) and poly[(methyloctyliminium)-2-hydroxy propanodiyl chloride] (2-OH-33R8). Methyl orange incorporation and study of viscosity showed that increase of the side chain length of the ionene enhances the ability to form globular hydrophobic microdomains. Catalytic hydrolysis of PNPB follows the order 2-OH-33R8 2-OH-33R4 > 2-OH-33R1, and 2-OH-33R8 has the lowest pKa that may reflect its higher hydrophobicity, which apparently influences the ionene nanoreactor reactivity. A lower pKa indicates easier deprotonation of the alkoxide group, which participates more effectively in the reaction and the 2-OH-33R8 functionalized ionene acts as a specially effective catalytic homogeneous nanoreactor.
Ambident Reactivity of Phenolate Anions Revisited: A Quantitative Approach to Phenolate Reactivities
Mayer, Robert J.,Breugst, Martin,Hampel, Nathalie,Ofial, Armin R.,Mayr, Herbert
, p. 8837 - 8858 (2019/07/08)
Prompted by the observation that the regioselectivities of phenolate reactions (C versus O attack) are opposite to the predictions by the principle of hard and soft acids and bases, we performed a comprehensive experimental and computational investigation of phenolate reactivities. Rate and equilibrium constants for the reactions of various phenolate ions with benzhydrylium ions (Aryl2CH+) and structurally related quinone methides have been determined photometrically in polar aprotic solvents. Quantum chemical calculations at the SMD(MeCN)/M06-2X/6-31+G(d,p) level confirmed that O attack is generally favored under kinetically controlled conditions, whereas C attack is favored under thermodynamically controlled conditions. Exceptions are diffusion-limited reactions with strong electrophiles, which give mixtures of products arising from O and C attack, as well as reactions with metal alkoxides in nonpolar solvents, where oxygen attack is blocked by strong ion pairing. The Lewis basicity (LB) and nucleophilicity (N, sN) parameters of phenolates determined in this work can be used to predict whether their reactions with electrophiles are kinetically or thermodynamically controlled and whether the rates are activation- or diffusion-limited. Comparison of the measured rate constants for the reactions of phenolates with carbocations with the Gibbs energies for single-electron transfer manifests that these reactions proceed via polar mechanisms.
Tuning the intramolecular charge transfer (ICT) process in push-pull systems: Effect of nitro groups
Panja, Sumit Kumar,Dwivedi, Nidhi,Saha, Satyen
, p. 105786 - 105794 (2016/11/18)
The intramolecular charge transfer (ICT) process in donor-acceptor systems has tremendous importance in various physical and biological systems. Three nitrophenolate salts were synthesized and studied here. The ICT and π → π? transition processes were identified in these derivatives using UV-Vis spectroscopy and theoretical calculations. It was observed that by simple substitution with nitro groups, one can generate and control the ICT process by regulating the charge distribution over the molecule. While for a monosubstitute nitro derivative, only one ICT band was observed, additional ICT processes can be generated at will by introducing a second nitro group. The intensity of this second ICT channel can be regulated with introduction of a third nitro group. Further, the association constants and solvation processes for these potassium nitrophenolate derivatives were found to be drastically dependent on the number of ICT channels present in the molecule. Theoretical studies (MEP analysis) support the experimental observations presented here. The results show that by simply introducing additional acceptor groups to the system, one can tune the ICT band efficiently in a conjugate system.