124-41-4Relevant articles and documents
Broensted Acidities of Carbonyl Hydride Complexes of Iron, Ruthenium, and Osmium: pKa Values and Deprotonation Rates in Methanol Solution
Walker, Howard W.,Pearson, Ralph G.,Ford, Peter C.
, p. 1179 - 1186 (1983)
Reported are kinetics studies of the reaction of methoxide ion with several mononuclear and polynuclear carbonyl hydride complexes HxMy(CO)z of the iron triad.Deprotonation of the hydrides to give the conjugate base anions occurs with moderate second-order rate constants (ca. 101-104 M-1s-1), considerably smaller than those of oxygen or nitrogen acids of comparable thermodynamic strength under similar conditions.The relative slowness of these reactions is interpreted in terms of possible electronic and structural rearrangements of substrate and solvent occuring as the result of the deprotonation.In addition the kinetics technique allows the measurement of the reverse reacton (protonation of the conjugate base by methanol) rate constants which are also comparatively small (ca. 0.05-25 s-1).The ratio of the forward and reverse rates gives the equilibrium constants from which the pKa's in methanol can be calculated.In several cases pKa's were confirmed by buffer/indicator techniques.From these and other published data are drawn the conclusions that bridging hydrides are more acidic than terminal hydrides and that hydrides of the lighter metals are more acidic than those of homologous heavier metals.Furthermore, it is shown than the substituent effect of replacing CO of a cluster by a trimethyl phosphite is to decrease significantly the acidity of that cluster's hydrides.
Kinetic Studies on the Decomposition of Most Typical Meisenheimer Complex of Sodium 1,1-Dimethoxy-2,4,6-trinitrocyclohexadienide in Methanol
Abe, Takehiro
, p. 1399 - 1405 (1980)
The whole decomposition of the Meisenheimer complex formed from 2,4,6-trinitroanisole (TNA) and sodium methoxide proceeds in three steps and obeys the first-order kinetics in each step.The rate of the whole decrease of concentration of the complex is given by -d(+->)/dt=(k1+>+k2)*+(k3+>+k4)*->-k5->*, where k denotes a rate constant.This leads to the modification of the conventional unimolecular mehanism shown by TNA*CH3O- -> TNA +CH3O-.
Identification of 1, 4-Dihydrothieno[3', 2':5, 6]thiopyrano [4, 3-c]pyrazole derivatives as human 5-lipooxygenase inhibitors
Hu, Jianshu,Zhu, Wei,Meng, Hu,Liu, Ying,Wang, Xin,Hu, Chun
, p. 642 - 647 (2014)
A series of novel 1,4-dihydrothieno[3',2':5,6]thiopyrano [4,3-c]-pyrazole-3-carboxamide derivatives were synthesized and evaluated for their inhibitory activity to human 5-lipo-oxygenase (5-LOX). Compound 7c was found to exhibit significant inhibition to human 5-LOX with IC50 value of 5.7 ± 0.9 μM. Compound 7c was further studied using molecular docking in order to delineate its structure-activity relationship and to gain insight into the design of effective 5-LOX inhibitors.
Standard molar enthalpies of formation of sodium alkoxides
Chandran,Srinivasan,Gopalan,Ganesan
, p. 449 - 454 (2007)
The molar enthalpies of solution of sodium in methanol, ethanol, and n-propanol and of sodium alkoxides in their corresponding alcohols were measured at T = 298.15 K using an isoperibol solution calorimeter. From these results and other auxiliary data, the standard molar enthalpies of formation Δf Hm{ring operator} (RONa,cr) of sodium methoxide, sodium ethoxide, and sodium n-propoxide were calculated and found to be {(-366.21 ± 1.38), (-413.39 ± 1.45), and (-441.57 ± 1.18)} kJ · mol-1, respectively. A linear correlation has been found between Δf Hm{ring operator} (RONa) and Δf Hm{ring operator} (ROH) for R = n-alkyl, enabling the prediction of data for other sodium alkoxides.
Synthesis and antimicrobial activities evaluation of some new thiadiazinone and thiadiazepinone derivatives bearing sulfonamide moiety
Dalloul, Hany M. M.,El-Nwairy, Khaled A.,Shorafa, Ali Z.,Abu Samaha, Ahmed S.
, p. 288 - 293 (2018)
A new series of novel functionalized 1,3,4-thiadiazin-5-ones and 1,3,4-thiadi-azepin-5-ones bearing sulfonamide moieties were synthesized via 1,3-dipolar cyclocondensation reaction of nitrilimines with α-mercaptoesters and mercaptosuccinic acid respectively. The structures of the prepared compounds were confirmed by spectral methods (IR, 1H-NMR, 13C-NMR and MS spectroscopy) and elemental analysis. The newly synthesized compounds were screened for their in vitro antimicrobial activity. Some of titled compounds exhibited significant antimicrobial activity on several strains of microbes.
Synthesis and evaluation of the cytotoxic activity of water-soluble cationic organometallic complexes of the type [Pt(η1-C2H4OMe)(L)(phen)]+ (L = NH3, DMSO; phen = 1,10-phenanthroline)
De Castro, Federica,Stefàno, Erika,Migoni, Danilo,Iaconisi, Giorgia N.,Muscella, Antonella,Marsigliante, Santo,Benedetti, Michele,Fanizzi, Francesco P.
, (2021)
Starting from the [PtCl(η1-C2H4OMe)(phen)] (phen = 1,10-phenanthroline, 1) platinum(II) precursor, we synthesized and characterized by multinuclear NMR new [Pt(η1-C2H4OMe)(L)(phen)]+ (L = NH3, 2; DMSO, 3) complexes. These organometallic species, potentially able to interact with cell membrane organic cation transporters (OCT), violating some of the classical rules for antitumor activity of cisplatin analogues, were evaluated for their cytotoxicity. Interestingly, despite both complexes 2 and 3 resulting in greater cell uptake than cisplatin in selected tumor cell lines, only 3 showed comparable or higher antitumor activity. General low cytotoxicity of complex 2 in the tested cell lines (SH-SY5Y, SK-OV-3, Hep-G2, Caco-2, HeLa, MCF-7, MG-63, ZL-65) appeared to depend on its stability towards solvolysis in neutral water, as assessed by NMR monitoring. Differently, the [Pt(η1-C2H4OMe)(DMSO)(phen)]+ (3) complex was easily hydrolyzed in neutral water, resulting in a comparable or higher cytotoxicity in cancer cells with respect to cisplatin. Further, both IC50 values and the uptake profiles of the active complex appeared quite different in the used cell lines, suggesting the occurrence of diversified biological effects. Nevertheless, further studies on the metabolism of complex 3 should be performed before planning its possible use in tissue- and tumor-specific drug design.
Anti-Helicobacter pylori activity of some newly synthesized derivatives of xanthone
Klesiewicz, Karolina,Karczewska, Elzbieta,Budak, Alicja,Marona, Henryk,Szkaradek, Natalia
, p. 825 - 834 (2016)
A series of 20 xanthone derivatives was synthesized and evaluated for anti-Helicobacter pylori (H. pylori) activity. Qualitative and quantitative in vitro tests using the Kirby-Bauer method (agar disc-diffusion method) were performed. The tested compounds were screened against clarithromycin- and/or metronidazole-resistant strains of H. pylori. As a reference, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial strains were examined. On the basis of microbiological assays, xanthones can be considered as potential anti-H. pylori agents. They displayed significant activity against the examined strains, which was higher against the bacteria resistant to metronidazole than clarithromycin. The lowest MIC values ranging up to 20 mg l-1 were observed for the following compounds: 3, 4, 8, 9, 12, 19 (against the metronidazole-resistant strains) and the compound 10 (against the clarithromycin-resistant strain). These preliminary results for screening of xanthone derivatives form a part of an ongoing study of the structure-activity relationships of a large group of compounds. Microbiological assays will be conducted afterwards to determine the mechanism of xanthones' action against H. pylori.
Investigation of the crystal structures and magnetic features of two bis(dithiolato)nickelate salts with flexible organic cations
Chen, Xuan-Rong,Zhang, Zhen-Min,Luo, Min,Liu, Hang,Yuan, Jia-Yi
, p. 353 - 362 (2021)
Two bis(dithiolato)nickel salts with different flexible ammonium counterions, [Et3MeN][Ni(dmit)2] (1) and [(i-Bu)Et3N][Ni(dmit)2] (2) (dmit2? = 2-thioxo-1,3-dithiole-4,5-dithiolate, Et3MeN+ = triethylmethylammonium, (i-Bu)Et3N+ = triethylisobutylammonium), are prepared and identified by powder X-ray diffraction (PXRD) patterns and single-crystal X-ray diffraction. Salt 1 crystallizes in the triclinic space group P???1 at 293?K. The anions and cations in 1 form alternating layered arrangements along the a-axis direction. Salt 2 belongs to the monoclinic crystal system and space group P21/n. The anions and cations in 2 form separate columnar stacks along bc-plane direction. The neighboring anions are stacked as dimers in the anion columnar stacks of 2. The magnetic features of salts 1 and 2 show 1D alternating spin chain magnetic exchange behavior, and the magnetic experimental data are well fitted through a spin chain magnetic model. The difference in the crystal structures and magnetic properties between the two new salts 1 and 2 fully demonstrates that the magnetic properties are dependent on the alignment of the [Ni(dmit)2]? anions, which are related to the flexible organic cations. Graphical abstract: [Figure not available: see fulltext.]
Near-infrared light-controlled circularly polarized luminescence of self-organized emissive helical superstructures assisted by upconversion nanoparticles
Juan, Ao,Sun, Hao,Qiao, Jinghui,Guo, Jinbao
, p. 13649 - 13652 (2020)
A near-infrared light-driven self-organized emissive helical superstructure was constructed by doping a new chiral fluorescent photoswitch and upconversion nanoparticles (UCNPs) into a nematic LC. The reversible switching of circularly polarized luminescence (CPL) can be achieved by modulating the power intensity of the 980 nm NIR excitation light.
Synthesis and herbicidal activities of novel 3-(α-hydroxymethylene) pyrrolidine-2,4-dione derivatives containing a cyclopropane moiety
Zhu, You-Quan,Zhang, Jin,Yuan, Yan-Wei,Xie, Li-Fen,Xu, Hai-Zhen,Zou, Xiao-Mao,Yang, Hua-Zheng
, p. 202 - 205 (2013)
A variety of novel 3-(α-hydroxymethylene)pyrrolidine-2,4-dione derivatives containing a cyclopropane moiety were designed and synthesized in satisfactory yields. Their structures were confirmed by 1H NMR and HRMS. The bioassays indicated that most of the title compounds displayed some extent herbicidal activities at 100 mg/mL.
