نتایج جستجو برای: 12 crown 4 ether
تعداد نتایج: 1739084 فیلتر نتایج به سال:
Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2) and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4). In these alkali metal complexes, not all crown ether O atoms participate in the coordination, which depicts the coordination ability of the C-, Si/C-, and Si-bonded O atoms. Furthermore, the inverse case—the coordination of the larg...
Liquid-liquid extractive-spectrophotometric studies of sodium ion complexes of 18crown-6(18C6), dibenzo-18-crown-6(DB18C6), 15-crown-5(15C5), and 12-crown-4(12C4) and anionic dyes [4-(2-pyridylazo)-resorcinol monosodium salt monohydrate (PAR), Eriochrom Black T (EBT), and methyl orange (MOR)] and sodium picrate (PICRAT) as the counter ion are described. The overall extraction equilibrium consta...
The asymmetric unit of the title cocrystal, [Sn(CH(3))(C(6)H(5))Cl(2)(H(2)O)(2)]·C(10)H(20)O(5), contains two independent for-mula units. The organotin molecules exhibit a six-coordinate metal atom and are linked to the crown ether molecules by water-crown ether O-H⋯O hydrogen bonds into a linear chain running along [101]. Each coordinated water mol-ecule forms a pair of hydrogen bonds to the s...
The polyfunctional and highly reactive bio-polymer, the chitosan was first regioselectively converted into dialkylated chitosan using dimsyl anionic solution(NaH in DMSO) and bromodecane after protecting amino groups by phthalic anhydride. The dibenzo-18-crown-6-ether, on the other hand, was converted into its carbonyl derivatives via Duff reaction prior to incorporate into chitosan by Schiff b...
Reaction of [U(TrenTIPS )(PH2 )] (1, TrenTIPS =N(CH2 CH2 NSiPri3 )3 ) with C6 H5 CH2 K and [U(TrenTIPS )(THF)][BPh4 ] (2) afforded a rare diuranium parent phosphinidiide complex [{U(TrenTIPS )}2 (μ-PH)] (3). Treatment of 3 with C6 H5 CH2 K and two equivalents of benzo-15-crown-5 ether (B15C5) gave the diuranium μ-phosphido complex [{U(TrenTIPS )}2 (μ-P)][K(B15C5)2 ] (4). Alternatively, reaction...
In the cation of the title compound, [Mn(C(18)H(18)N(2)O(4))(H(2)O)(2)]ClO(4)·0.5C(12)H(24)O(6)·H(2)O, the Mn(III) ion is coordinated by two water O atoms, and two O atoms and two N atoms from the tetradentate 6,6'-dimeth-oxy-2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]di-phenolate ligand, completing a distorted octa-hedral geometry. One O atom of the 18-crown-6-ether is disordered over two ...
Water soluble gold nanoparticles protected by lipoic acid were obtained and further functionalized by standard coupling reaction with 1-naphtylamine, 4-aminoantipyrine, and 4'-aminobenzo-15-crown-5 ether. Derivatives of lipoic acid with 1-naphtylamine, 4-aminoantipyrine, and 4'-aminobenzo-15-crown-5 ether were also obtained and characterized. All these were tested for their antimicrobial activi...
The elucidation of the structural requirements for molecular recognition by the crown ether (18-crown-6)-2,3,11,12-tetracarboxylic acid (18c6H(4)) and its cationic complexes constitutes a topic of current fundamental and practical interest in catalysis and analytical sciences. The flexibility of the central ether ring and its four carboxyl side arms poses important challenges to experimental an...
the do1(18c6)fi (mwli. na. k and i 8c6=18-crown-6) complexes have been chosen as the model systems toinvestigate the nature of chemical bonds between alkali metal cations and large mffitidentaie orgmnic ligands.the b3lyp/6-3i+g(d,p) level of calculation has been used for obtaining equilibrium geernetnes and p(r)functions (electron density distributions). by the aid of fundamental physical theor...
The title compound, C33H35N3O5, is the product of the multicomponent condensation of 1-benzyl-4-eth-oxy-carbonyl-piperidin-3-one with 1,5-bis-(2-formyl-phen-oxy)-3-oxapentane and ammonium acetate. The mol-ecule comprises a penta-cyclic system containing the aza-14-crown-4-ether macrocycle, tetra-hydro-pyrimidine, tetra-hydro-pyridine and two benzene rings. The aza-14-crown-4-ether ring adopts a...
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