Category: 14187-32-7

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. 14187-32-7, C20H24O6. A document type is Article, introducing its new discovery., Recommanded Product: Dibenzo-18-crown-6

The (9-anthracenyl)methylammonium and (9-anthracenyl)benzylammonium tetrakis(hexafluorophosphate) salts give hydrogen-bonded complexes in CH2Cl2 with aromatic crown ethers containing dibenzo (DB) or dinaphtho (DN) units. The association constants vary from 3 x 103 to 1 x 106 M-1 in CH2Cl2, depending on the specific ammonium cation and crown ether involved. In a number of cases, pseudorotaxane-like geometries for the complexes are demonstrated by (a) 1H NMR spectroscopy in solution, (b) X-ray crystallography in the solid state, and (c) mass spectrometry in the gas phase. The results obtained by absorption, emission, and excitation spectroscopy and excited lifetimes show that, as a consequence of the hydrogen bond driven recognition process, the anthracene chromophoric unit interacts with the aromatic units of the crown ethers. In the complexes involving the DB18C6, DB24C8, and DB30C10 macrocycles, the interaction leads to the complete quenching of the fluorescence of the dialkoxybenzene moieties and parallels sensitization of the anthracene fluorescence. In the complexes of 1/5-DN38C10, both the crown and the anthracene fluorescence are completely quenched, most likely by an energy-transfer cascade involving the triplet state of the dialkoxynaphthalene moiety. In the complexes of 2/3-DN30C10, the interaction between the anthracene moiety and the naphthalene rings of the crown ether is relatively strong, as indicated by the perturbation of the absorption bands, the disappearance of the fluorescence bands of the naphthalene- and anthracene-type chromophoric units, and the appearance of a new, broad fluorescence band. The complexes can also be formed by addition of CF3COOH or CF3SO3H to CH2Cl2 solutions containing crown ether and amine. The association process between DB24C8 and (9-anthracenyl)benzylammonium salt can be reversed quantitatively upon addition of a suitable base and the complex can be formed again after treatment with acid.

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Chiral Catalysts,
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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.14187-32-7, Name is Dibenzo-18-crown-6, molecular formula is C20H24O6. In a Article，once mentioned of 14187-32-7, category: chiral-catalyst

The reactions of benzo-15-crown-5 and dibenzo-18-crown-6 with 1 equiv. of [(mes)Ru(MeNO2)3]2+ (mes = 1,3,5-C6H3Me3) give the mononuclear complexes [(mes)Ru(eta6-benzo-15-crown-5)]2+ (1) and [(mes)Ru(eta6-dibenzo-18-crown-6)]2+ (2) in 50% yield. Similar reaction with 2 equiv. of [(mes)Ru(MeNO2)3]2+ produces the dinuclear complex [(mu-eta6:eta6-dibenzo-18-crown-6)Ru2(mes)2]4+ (3) in 96% yield as a 2:3 mixture of cis- and trans-isomers. Structures of 2(OTf)2 and trans-3(OTf)4 were confirmed by X-ray diffraction. The NMR titration showed that mononuclear dications 1 and 2 bind Na+ ion less effective (Ka = 600 and 250 M-1) than free benzo-15-crown-5 and dibenzo-18-crown-6 (Ka = 2 × 105 and 5 × 106 M-1). The dinuclear tetracation 3 does not bind Na+ within measurable limits of NMR titration method. The electrochemical behaviour of complexes 1-3 was studied in propylene carbonate solution. They exhibit a partially chemically reversible Ru(II)/Ru(I) reduction, which in the case of the dinuclear complex 3 proceeds through two slightly separated steps. The redox activity of the complexes is substantially unaffected by the presence of sodium ion.

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Chiral Catalysts,
Chiral catalysts – SlideShare

In an article, published in an article, once mentioned the application of 14187-32-7, Name is Dibenzo-18-crown-6,molecular formula is C20H24O6, is a conventional compound. this article was the specific content is as follows.COA of Formula: C20H24O6

A new complex [Cs(Db18C6)2]+[FeCl4] – was prepared and studied by X-ray diffraction (orthorhombic, space groupP21212,a = 22.934 A,b= 24.024 A,c= 16.665 A,Z= 8; direct method, anisotropic full-matrix least-squares refinement,R= 0.087 for all 8800 independent reflections; CAD4 automated diffractometer, lambdaMoK alpha. Two independent [FeCl 4]- anions have a slightly distorted tetrahedral structure. Two independent host-guest type complex cations [Cs(Db18C6) 2]+ have a sandwich structure. The Cs+ cation is located between two Db18C6 crown ligands below and above the centers of their 18-membered macrocycles and is coordinated by all 12 O atoms. The coordination polyhedron of Cs+ (C.N. 12) is a distorted hexagonal antiprism rotated toward a hexagonal prism.

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Chiral Catalysts,
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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.14187-32-7, Name is Dibenzo-18-crown-6, molecular formula is C20H24O6. In a Patent，once mentioned of 14187-32-7, Application In Synthesis of Dibenzo-18-crown-6

The present invention provides a compound having p38 MAP kinase inhibitory activity. Because of having p38 MAP kinase inhibitory activity, the compounds represented by the formula (I): wherein each symbol is as defined in the description, salts thereof, N-oxides thereof, solvates thereof, or prodrugs thereof are useful in preventing and/or treating diseases that are supposedly caused or deteriorated by abnormal production of cytokines including inflammatory cytokines or chemokines, or by overresponse thereto, namely cytokine-mediated diseases such as inflammatory diseases, respiratory diseases, cardiovascular diseases and bone diseases.

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Chiral Catalysts,
Chiral catalysts – SlideShare

In an article, published in an article, once mentioned the application of 14187-32-7, Name is Dibenzo-18-crown-6,molecular formula is C20H24O6, is a conventional compound. this article was the specific content is as follows.Application In Synthesis of Dibenzo-18-crown-6

Molecular complexation of six crown ethers with 2,4,6-trinitrotoluene has been studied using spectral methods.The association constants have been evaluated using PMR shift method.All these ethers form 1:1 complexes in 1,2-dichloroethane.The major contribution to the interaction arises from n and ? electrons.The 1H and 13C NMR studies provide some insight into the relative orientation of the donor and acceptor molecules in solution.

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Chiral Catalysts,
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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.14187-32-7, Name is Dibenzo-18-crown-6, molecular formula is C20H24O6. In a Article，once mentioned of 14187-32-7, Computed Properties of C20H24O6

The novel complex [K(Db18C6)(H2O)]+[K(Db1)] +(CuBr4)2- (I) was obtained. Its crystal structure (space group P21/c, a = 17.970 A, b = 29.838 A, c = 9.074 A, beta = 103.11, Z = 4) was studied by X-ray diffraction analysis, solved by the direct method, and refined by the least-squares method in the anisotropic approximation to R = 0.098 from 6220 independent reflections (CAD-4 automated diffractometer, lambdaMo Kalpha). In both “guest-host” complex ions, the K+ cation is in the cavity of the crown ligand Db18C6 and is coordinated by all its O atoms, as well as by a Br atom of the complex anion [CuBr4]2- or the water O atom. The coordination of either K+ cation is extended to a hexagonal bipyramid by a weak K+ ? pi C-C) bond to two C atoms of the benzene ring of the adjacent ligand Db18C6. In the crystal, the complex anions and cations are united into infinite double chains through the above contacts and the interion hydrogen bonds O-H-Br.

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Chiral Catalysts,
Chiral catalysts – SlideShare

Reference of 14187-32-7, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 14187-32-7, Name is Dibenzo-18-crown-6, molecular formula is C20H24O6. In a Article，once mentioned of 14187-32-7

Complex formation constants of six crown ethers, benzo- 12-crown-4, benzo- 15-crown-5, benzo-18-crown-6, dibenzo-18-crown-6, dibenzo-21-crown-7, and dibenzo-24-crown-8 (B12C4, B15C5, B18C6, DB18C6, DB21C7, and DB24C8, respectively) with alkali and alkaline earth metal cations have been measured in aqueous solutions by capillary zone electrophoresis. The procedure involved the measurement of change in the electrophoretic mobility of the ligands upon increasing the metal ion concentration in the carrier electrolyte solution. A substantial increase in apparent electrophoretic mobility was observed for the crown ethers with increasing concentrations of the metal ions. The variations in increased electrophoretic mobility were attributed to the different stability of the complexes formed between the cations and the crown ether. The complex formation constants obtained with alkali metal cations were in the orders of: K+ > Na+ > Rb+ > Cs+ (B18C6), K+ > Na+ > Rb+ > Cs+ (DB18C6), Rb+ > Cs+ > K+ (DB21C7), and Rb+ > Cs+ (DB24C8); while with alkaline earth metal cations it was: Ba2+ > Sr2+ > Ca2+ (B18C6) and Ba2+ > Sr2+ (DB18C6). All the ligands examined showed no change in their apparent electrophoretic mobility upon changing Li+ and Mg2+ concentrations, indicating less reactivity with the cations. From the results obtained in this study, the electrophoretic method was proved to be preferable for analyzing the reactivity of the crown ethers and the selectivity toward metal cations.

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 14187-32-7 is helpful to your research., Reference of 14187-32-7

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Chiral Catalysts,
Chiral catalysts – SlideShare

The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.14187-32-7, Name is Dibenzo-18-crown-6, molecular formula is C20H24O6. In a Article，once mentioned of 14187-32-7, Recommanded Product: Dibenzo-18-crown-6

On the basis of the novel heterocyclic beta-diketone, 4-sebacoylbis(1-phenyl-3-methyl-5-pyrazolone (H2SbBP), three new lanthanide complexes Tb2(SbBP)3(H2O) 2 (1), Gd2(SbBP)3(H2O)2 (2), and [Tb(SbBP)2] [Na(DB18C6)H2O] (3) have been synthesized and characterized by various spectroscopic techniques. The single-crystal X-ray diffraction analysis of 3 reveals that the complex crystallizes in the monoclinic space group C2/c with a = 25.300(6) A, b = 19.204(7) A, c = 15.391(3) A, beta = 93.17(3), and V = 7466(4) A3. The crystal structure of 3 is heterodinuclear and features a Tb3+ center surrounded by two tetradentate bispyrazolone ligands in a somewhat distorted square-antiprismatic geometry. The Na + coordination environment is distorted hexagonal pyramidal and involves six oxygen atoms furnished by DB18C6 and one oxygen atom from a water molecule. The X-ray diffraction study of 3 also revealed an interesting 1D molecular ladder structure based on C-H/pi, intra- and intermolecular hydrogen-bonding interactions. The photophysical properties of 1 and 3 in solid state have been investigated, and the quantum yields and 5D 4 lifetimes were found to be 4.82 ± 0.01% and 18.13 ± 0.82% and 1.11 ± 0.01 and 2.82 ± 0.02 ms, respectively.

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Chiral Catalysts,
Chiral catalysts – SlideShare

The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.14187-32-7, Name is Dibenzo-18-crown-6, molecular formula is C20H24O6. In a Article，once mentioned of 14187-32-7, category: chiral-catalyst

The use of dibenzo-18-crown-6 in the synthesis of trimethylaluminium adducts of KNO3 results in the formation of a 1/1 adduct, .The crystal structure of has been determined from single-crystal X-ray diffraction data collected by counter methods.The title compound crystallizes in the monoclinic space group P21/c (N. 14) with unit cell parameters a = 11.804(3), b = 28.828(4), c = 9.118(3) Angstroem, beta = 96.61(3) deg, Dcalc = 1.23 for Z = 4.Least-squares refinement gave a final conventional R value of 0.045 for 983 independent observed reflactions.The potassium atom is centered among the six oxygen atoms of the crown at an average K…O contact of 2.74(2) Angstroem.Its environment is completed by an oxygen atom of a nitrate anion (2.88 Angstroem) and a benzo group (>3.44 Angstroem) of a neighboring crown ether.The trimethylaluminium moeity is coordinated to the nitrate anion by an oxygen atom at an Al-O bond distance of 1.92(1) Angstroem.

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Chiral Catalysts,
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In an article, published in an article, once mentioned the application of 14187-32-7, Name is Dibenzo-18-crown-6,molecular formula is C20H24O6, is a conventional compound. this article was the specific content is as follows.Application In Synthesis of Dibenzo-18-crown-6

The apparent molar volumes of equimolar concentrations of 18-crown-6-ether (CE) or dibenzo-18-crown-6-ether (B2CE) and MCl (M = Na, K, or Cs) or MI in dilute solutions of anhydrous methanol, acetonitrile and dimethylsulfoxide have been calculated from density data measured at 25 deg C.After extrapolation to infinite dilution these results together with the apparent molar volumes of the crown ethers and the alkali metal halides were used to calculate the limiting partial molar volume change for the formation of the complexes.By noting that the charge of the complexed cation has been shown to be completely shielded from the solvent, the volume of complexation can be assumed to be a good estimation of the volume change due to electrostriction of the solvent by the cationic charge.The results are compared to the predictions of the Hepler equation. Key Words: 18-crown-6-ether; dibenzo-18-crown-6-ether; apparent molar volume; partial molar volume change on complex formation; methanol; acetonitrile; dimethylsulfoxide.

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Chiral Catalysts,
Chiral catalysts – SlideShare