Tag: M.W:200-300

Application of 14098-44-3, An article , which mentions 14098-44-3, molecular formula is C14H20O5. The compound – Benzo-15-crown-5 played an important role in people’s production and life.

THE SYNTHESIS OF SOME AROMATIC CROWN ETHER DERIVATIVES AND THEIR ION-SELECTIVE ELECTRODE PROPERTIES

The synthesis of alkyl, nitro and halogeno derivatives of benzo-15-crown-5, benzo-18-crown-6 and naphtho-15-crown-5 has been reported.Also some novel ester type bis(crown ether)s have been prepared.Some of the compounds have been characterized as electroactive substances in PVC membrane ion-selective electrodes.

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In an article, published in an article, once mentioned the application of 33100-27-5, Name is 1,4,7,10,13-Pentaoxacyclopentadecane,molecular formula is C10H20O5, is a conventional compound. this article was the specific content is as follows.Application In Synthesis of 1,4,7,10,13-Pentaoxacyclopentadecane

Steric and stereoelectronic effects in aza crown ether complexes

Stability constants and enthalpy changes determined by calorimetric titrations and supported by selected NMR titrations are reported for the complexation of sodium and potassium cations with 18 different crown ethers containing nitrogen atoms with different number, location and substitution pattern. The data, measured in methanol mostly with potassium salts, are compared to literature data; they show striking differences between all-oxygen analogs and the macrocycles with NH groups. In contrast, affinities with aza crown ethers bearing alkyl groups at the nitrogen as well as with the cryptand [2.2.2] come closer to the complexation free energies predicted from the number and electron donating capacity of the ligand heteroatoms. This is rationalised on the basis of molecular mechanics calculations, showing that a NH-containing crown predominates in conformations with axial N lone pairs, due to their repulsive electrostatic interactions with the ring oxygen atoms. Replacement of the hydrogen by alkyl groups forces the lone pairs to an equatorial position, thus enabling better complex formation, as borne out by experiment. In line with these arguments the IgK differences are with some exceptions more due to DeltaH than to TDeltaS differences. The calorimetric data show linear isoequilibrium correlations between TDeltaS and DeltaH, with slopes between those observed with other crown ether and cryptand complexes. Preliminary investigations of some synthetic macrocyclic amide precursors yield appreciable complexation only, if the two carbonyl oxygens can come in close contact with the guest cation. Computer aided molecular modelling shows that this is possible in a small 15C5-derivative, in which the polyethylenglycol cycle only serves as ring template without binding contributions from the ether oxygen atoms.

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The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.14098-44-3, Name is Benzo-15-crown-5, molecular formula is C14H20O5. In a Article£¬once mentioned of 14098-44-3, Recommanded Product: Benzo-15-crown-5

Thermodynamics of Solvent Extraction of Metal Picrates with Crown Ethers: Enthalpy-Entropy Compensation. Part 1. Stoicheiometric 1:1 Complexation

Quantitative solvent extractions were performed in the water-dichloromethane system at 10-25 deg C to give the extraction equilibrium constants (Kex) and the thermodynamic quantities (DeltaH0 and DeltaS0) for the ion-pair extraction of aqueous alkali (Li(1+)-Cs(1+)), alkaline earth (Ca(2+)-Ba(2+)), and some heavy metal (Ag(1+), Tl(1+)) picrates with 15-crown-5, benzo-15-crown-5, cis-cyclohexano-15-crown-5, 16-crown-5, 15-(2-methoxyethoxy)methyl-15-methyl-16-crown-5, 18-crown-6, dibenzo-18-crown-6, and dibenzo-24-crown-8.The cation-binding abilities and relative cation selectivities of the ligands are discussed from the thermodynamic point of view.Global treatment of the thermodynamic data obtained in the present and previous works reveals not only that, as is the case with the complexation in the homogeneous phase, the enthalpy-entropy compensation effect holds in the solvent extraction system, but also the DeltaH0 vs.TDeltaS0 plot affords the characteristic slope (alpha) and intercept (TDeltaS0) which are comparable to the corresponding values obtained for the homogeneous-phase complexation.This indicates that the conformational change and the extent of desolvation upon cation binding by crown ethers are quite analogous both in the homogeneous phase and in the solvent extraction beyond the apparent differences in the phase and the complexed species involved.

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Electric Literature of 94-91-7, Chemistry can be defined as the study of matter and the changes it undergoes. You¡¯ll sometimes hear it called the central science because it is the connection between physics and all the other sciences, starting with biology.94-91-7, Name is N,N’-Bis(salicylidene)-1,2-propanediamine, molecular formula is C17H18N2O2. In a patent, introducing its new discovery.

Synthesis, crystal structure and magnetic characterization of a new phenoxo-bridged binuclear manganese(III) Schiff base complex exhibiting single-molecule-magnet behavior

A new phenoxo-bridged binuclear manganese(III) Schiff base complex, [Mn(L)(N3)]2 (1) where L = N,N?-bis(salicylidene)-1,2-propanediamine has been synthesized and characterized by IR, elemental analysis, crystal structure analysis and variable temperature magnetic susceptibility measurements. The single crystal X-ray diffraction reveals that the structure is dimeric with each phenolate oxygen atom acting as a bridge between two symmetry equivalent Mn atoms. Low temperature magnetic study shows that the complex exhibits intra-dimer ferromagnetic exchange and single-molecule-magnet (SMM) behavior as well.

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The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.33100-27-5, Name is 1,4,7,10,13-Pentaoxacyclopentadecane, molecular formula is C10H20O5. In a Article£¬once mentioned of 33100-27-5, Recommanded Product: 33100-27-5

Nitrido Complexes of Molybdenum (V); Syntheses, IR, and EPR Spectra. Crystal Structure of 24*2THF

The molybdenum nitrido complexes (1), 2 (2), and 24*2THF (3) have been prepared by reactions of MoNCl3 with sodium naphthalide in tetrahydrofurane (THF) in the presence of 15-crown-5.According to the EPR spectra and in agreement with IR spectra. 1 forms dimeric ions 22- via chloro bridges, whereas tetrameric units 48- and 44- are present in 2 and 3, respectively. 3 was characterized by an X-ray structure determination: space group P21/c, Z = 2, 1964 observed unique reflexions, R = 0.12.Lattice dimensions at -90 deg C : a = 1173(1); b = 2083(3); c = 1750(2) pm; beta = 112.3(7) deg.The structure consists of an ensemble of associated ions around the central 44- unit.In the latter, the four Mo atoms from a square and are bridged via linear, symmetric Mo<*>N-Mo groups.The (MoN)4 square is enclosed in a cube of eight Cl atoms, the Mo atoms occupying four of the cube edges.Two Na+ ions are situated in the centres of two opposing cube faces, each of the other two Na+ ions is coordinated with two Cl atoms outside of the cube; these Na+ ions are also coordinated with one THF molecule and with one 15-crown-5 molecule, respectively.The crystal also contains non-coordinated THF molecules, which exhibit strong thermal motion and/ or disorder. – Keywords: Nitrido Complexes of Molybdenum(V), Synthses, IR Spectra, EPR Spectra, Crystal Structure

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Children learn through play, and they learn more than adults might expect. Science experiments are a great way to spark their curiosity, get their minds active, and encourage them to do something that doesn¡¯t involve a screen. 33100-27-5, C10H20O5. A document type is Article, introducing its new discovery., Product Details of 33100-27-5

Spectroscopic Investigation of the Ion -; Crystal Structure of

(X = Cl, Br) and have been prepared by reactions of X2V(N3S2) with sodium fluoride in acetonitrile suspensions in the presence of 15-crown-5 and benzo-15-crown-5, respectively.The 15-N-labeled complex was also prepared and characterized by 15N, 19F, and 51V NMR spectra, as well as by IR spectroscopy.Whereas the crystal structure of , owing to disorder of the crown ether molecule, could be refined only to an R-value of 0.16 (space group C2/m, Z = 4, a = 1995.4(11); b = 1016.2(6); c = 1047.2(8) pm; beta = 100.83(4) deg at -65 deg C), the crystal structure of the corresponding was determined without complications.Space group P21/c, Z = 4, 5565 observed independent reflexion.R = 0.036.Lattic dimensions at 20 deg C; a = 1198.9(6); b = 970.3(5); c = 1918.2(10) pm; beta = 93.74(3) deg.The compound forms ion pairs, in which the sodium atom is seven-coordinated by the oxygen atoms of the crown ether molecule, the fluorine atom and one chlorine atom of the trigonal-bipyramidal – unit.The vanadium atom is part of a planar VN3S2 ring; fluorine and two nitrogen atoms of the cyclothiazeno ring occupy the equatorial positions. – Keywords: Fluoro-Chloro-Cyclothiazeno Complexes of Vanadium, 15N NMR Spectra; 51V NMR Spectra, IR Spectra, Crystal Structure

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Electric Literature of 14098-44-3, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 14098-44-3, Name is Benzo-15-crown-5, molecular formula is C14H20O5. In a Article£¬once mentioned of 14098-44-3

Solid-state 23Na nuclear magnetic resonance of sodium complexes with crown ethers, cryptands, and naturally occurring antibiotic ionophores: A direct probe to the sodium-binding sites

We report a systematic solid-state 23Na nuclear magnetic resonance study of sodium complexes with crown ethers, cryptands, and naturally occurring antibiotic ionophores. Precise information about 23Na quadrupole coupling constants and chemical shifts was determined from analysis of 23Na magic-angle spinning (MAS) NMR spectra. We found that the experimental 23Na chemical shifts can be related to an empirical parameter that is a function of the atomic valence of the donor ligand, the Na+-ligand distance, and the coordination number (CN) around the Na+ ion of interest. A reasonably good correlation was also observed between the 23Na quadrupole parameters measured in CDCl3 solution and those measured in the solid state, indicating that the cation exchange is slow in CDCl3. In MeOH solution, however, neither 23Na quadrupole parameters nor chemical shifts of the Na-ionophore complexes show correlation with the corresponding solid-state data. Finally, we report the 23Na chemical shift tensor in Na(12C4)2ClO4: delta11 = delta22 = -1 ppm and delta33 = -15 ppm.

The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 14098-44-3 is helpful to your research., Electric Literature of 14098-44-3

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Related Products of 14098-44-3, An article , which mentions 14098-44-3, molecular formula is C14H20O5. The compound – Benzo-15-crown-5 played an important role in people’s production and life.

Copper(II) bromide: A simple and selective monobromination reagent for electron-rich aromatic compounds

Copper(II) bromide was found to be a simple and efficient reagent for monobromination of electron-rich aromatic compounds at room temperature. The reaction proceeded smoothly with phenols, aryl alkyl ethers, and aromatic amines to afford the corresponding monobrominated product selectively in moderate to good yields. Copyright Taylor & Francis Group, LLC.

I hope this article can help some friends in scientific research. I am very proud of our efforts over the past few months and hope to 14098-44-3, help many people in the next few years., Related Products of 14098-44-3

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The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.14098-44-3, Name is Benzo-15-crown-5, molecular formula is C14H20O5. In a Article£¬once mentioned of 14098-44-3, COA of Formula: C14H20O5

Electrophile-promoted Fe-to-N2 hydride migration in highly reduced Fe(N2)(H) complexes

One of the emerging challenges associated with developing robust synthetic nitrogen fixation catalysts is the competitive formation of hydride species that can play a role in catalyst deactivation or lead to undesired hydrogen evolution reactivity (HER). It is hence desirable to devise synthetic systems where metal hydrides can migrate directly to coordinated N2 in reductive N-H bond-forming steps, thereby enabling productive incorporation into desired reduced N2-products. Relevant examples of this type of reactivity in synthetic model systems are limited. In this manuscript we describe the migration of an iron hydride (Fe-H) to Nalpha of a disilylhydrazido(2-) ligand (FeNNR2) derived from N2via double-silylation in a preceding step. This is an uncommon reactivity pattern in general; well-characterized examples of hydride/alkyl migrations to metal heteroatom bonds (e.g., (R)MNR? ? M-N(R)R?) are very rare. Mechanistic data establish the Fe-to-Nalpha hydride migration to be intramolecular. The resulting disilylhydrazido(1-) intermediate can be isolated by trapping with CNtBu, and the disilylhydrazine product can then be liberated upon treatment with an additional acid equivalent, demonstrating the net incorporation of an Fe-H equivalent into an N-fixed product.

The reactant in an enzyme-catalyzed reaction is called a substrate. Enzyme inhibitors cause a decrease in the reaction rate of an enzyme-catalyzed reaction.I hope my blog about 14098-44-3 is helpful to your research., COA of Formula: C14H20O5

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The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.23190-16-1, Name is (1R,2S)-(?)-2-Amino-1,2-diphenylethanol, molecular formula is C6H5CH(NH2)CH(C6H5)OH. In a Article£¬once mentioned of 23190-16-1, Application In Synthesis of (1R,2S)-(?)-2-Amino-1,2-diphenylethanol

Biomimetic chirality sensing with pyridoxal-5?-phosphate

Pyridoxal-5?-phosphate (PLP) is introduced to a biomimetic indicator displacement assay for simultaneous determination of the absolute configuration, enantiomeric composition and concentration of unprotected amino acids, amino alcohols and amines. The chiroptical assay is based on fast imine metathesis with a PLP aryl imine probe to capture the target compound for circular dichroism and fluorescence sensing analysis. The substrate binding yields characteristic Cotton effects that provide information about the target compound ee and the synchronous release of the indicator results in a nonenantioselective off-on fluorescence response that is independent of the enantiomeric sample composition and readily correlated to the total analyte concentration.

Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.Application In Synthesis of (1R,2S)-(?)-2-Amino-1,2-diphenylethanol, you can also check out more blogs about23190-16-1

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