90-02-8Relevant articles and documents
Acceleration Effect of Fe(II), Co(II), Ni(II) and Cu(II) on the Hydrolysis Rate of Ortho or Para-Hydroxy Schiff Bases
El-Taher
, p. 815 - 820 (1998)
The kinetics of hydrolysis of ortho- or para-hydroxybenzylidene-4-benzidine Schiff bases have been examined in the pH range 1.70-11.90, in aqueous media containing 20wt% dioxane, at 20°C. In basic media, pH > 8.47, a slight increase in the hydrolysis reaction rate of the Schiff bases is observed. In such basic media, the rate-controlling step is the attack of hydroxide ion on the ionized Schiff base. Below pH 6.82, the rate-determining step is ascribed to be the attack of water molecules on the protonated substrate. The effects of Fe(II), Co(II), Ni(II) and Cu(II) ions on the hydrolysis reaction rate of the Schiff bases have been studied and discussed on the basis of formation of a monocyclic chelate rings. The various thermodynamic parameters have also been evaluated and discussed.
One-step construction of a novel AIE probe based on diaminomaleonitrile and its application in double-detection of hypochlorites and formaldehyde gas
Wen, Xiaoye,Yan, Li,Fan, Zhefeng
, p. 8155 - 8165 (2021)
As the environmental residues of formaldehyde and hypochlorites are very harmful to human health, a new simple and efficient aggregation-induced emission probe based on diaminomaleonitrile was designed and applied in the independent detection of hypochlorites and formaldehyde. The probe shows high selectivity and anti-interference ability against other potential competitive substances. ClO- promotes the oxidized splitting of CN in the probe, and induces evident color changes visible to the naked eye together with quenched fluorescence. The detection of ClO- by this probe was fast, sensitive, and visible to the naked eye. The detection limit of the probe to ClO- in the range of 0.70-20 μM is 18 nM. Through the condensation mechanism and with amine as the binding site of formaldehyde, the exposed amino group in the probe structure responds sensitively and efficiently to formaldehyde. The probe can effectively monitor 0.50-25 μM formaldehyde in aqueous solutions, with a detection limit as low as 42 nM. A portable solid sensor-a formaldehyde detection plate was built by directly covering the probe on a thin-layer chromatography plate. Thereby, formaldehyde gas can be effectively and sensitively detected, which offers a clue for developing solid-state formaldehyde-detection plates. The high experimental recovery rates prove that this new probe is highly promising in hypochlorite detection in the real water environment.
Spectroscopic studies of the interaction of aspirin and its important metabolite, salicylate ion, with DNA, A·T and G·C rich sequences
Bathaie,Nikfarjam,Rahmanpour,Moosavi-Movahedi
, p. 1077 - 1083 (2010)
Among different biological effects of acetylsalicylic acid (ASA), its anticancer property is controversial. Since ASA hydrolyzes rapidly to salicylic acid (SA), especially in the blood, interaction of both ASA and SA (as the small molecules) with ctDNA, oligo(dA·dT)15 and oligo(dG·dC)15, as a possible mechanism of their action, is investigated here. The results show that the rate of ASA hydrolysis in the absence and presence of ctDNA is similar. The spectrophotometric results indicate that both ASA and SA cooperatively bind to ctDNA. The binding constants (K) are (1.7 ± 0.7) × 103 M-1 and (6.7 ± 0.2) × 103 M-1 for ASA and SA, respectively. Both ligands quench the fluorescence emission of ethidium bromide (Et)-ctDNA complex. The Scatchard plots indicate the non-displacement based quenching (non-intercalative binding). The circular dichroism (CD) spectra of ASA- or SA-ctDsNA complexes show the minor distortion of ctDNA structure, with no characteristic peaks for intercalation of ligands. Tm of ctDNA is decreased up to 3 °C upon ASA binding. The CD results also indicate more distortions on oligo(dG·dC)15 structure due to the binding of both ASA and SA in comparison with oligo(dA·dT)15. All data indicate the more affinity for SA binding with DNA minor groove in comparison with ASA which has more hydrophobic character.
The antineoplastic action of o-substituted [1,2-bis(4-hydroxyphenyl)-ethylenediamine]dichloroplatinum (II) complexes and their methylethers
Karl,Schoenenberger
, p. 405 - 410 (1988)
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A DFT and experimental study of the spectroscopic and hydrolytic degradation behaviour of some benzylideneanilines
Nelson, Peter N.,Robertson, Tahjna I.
, (2021/10/12)
The spectroscopic and hydrolytic degradation behaviour of some N-benzylideneanilines are investigated experimentally and theoretically via high quality density function theoretical (DFT) modelling techniques. Their absorption and vibrational spectra, accurately predicted by DFT calculations, are highly dependent on the nature of the substituents on the aromatic rings, hence, though some of their spectroscopic features are similar, energetic differences exist due to differences in their electronic structures. Whereas the o-hydroxy aniline derived adducts undergo hydrolysis via two pathways, the most energetically economical of which is initiated by a fast enthalpy driven hydration, over a conservative free energy (ΔG?) barrier of 53 kJ mol?1, prior to the rate limiting entropy controlled lysis step which occurs via a conservative barrier of ca.132 kJ mol?1, all other compounds hydrolyse via a slower two-step pathway, limited by the hydration step. Barriers heights for both pathways are controlled primarily by the structure and hence, stability of the transition states, all of which are cyclic for both pathways.
A PROCESS FOR SELECTIVE OXIDATION OF ORTHO-CRESOL AND CATALYST THEREOF
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Page/Page column 9; 10, (2021/02/12)
The present invention relates to process for selective oxidation of o-cresol using heterogeneous catalyst. More particularly, the present invention relates to a selectively salicylaldehyde by oxidation of o-cresol, comprising steps of treating o-cresol with heterogeneous catalyst consisting of 3-7 % cobalt doped octahedral molecular sieves (OMS-2) support having Surface area between 80- 140 m2/g and pore size between 5 to 20 nm, the treatment is in presence of methanol and molecular oxygen at temperature between 60-85°C and pressure between 3 to 5 atm for time between 1 to 2 h. The process of present invention is to achieve high yield and conversion at mild reaction conditions.
Biocatalytic Cross-Coupling of Aryl Halides with a Genetically Engineered Photosensitizer Artificial Dehalogenase
Fu, Yu,Huang, Jian,Wu, Yuzhou,Liu, Xiaohong,Zhong, Fangrui,Wang, Jiangyun
supporting information, p. 617 - 622 (2021/02/03)
Devising artificial photoenzymes for abiological bond-forming reactions is of high synthetic value but also a tremendous challenge. Disclosed herein is the first photobiocatalytic cross-coupling of aryl halides enabled by a designer artificial dehalogenase, which features a genetically encoded benzophenone chromophore and site-specifically modified synthetic NiII(bpy) cofactor with tunable proximity to streamline the dual catalysis. Transient absorption studies suggest the likelihood of energy transfer activation in the elementary organometallic event. This design strategy is viable to significantly expand the catalytic repertoire of artificial photoenzymes for useful organic transformations.