نتایج جستجو برای: 12 crown 4 ether

تعداد نتایج: 1739084  

2017
Kirsten Reuter Fabian Dankert Carsten Donsbach

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...

1999
ÜMIT ÇAKIR BAKI ÇIÇEK Y. KEMAL YILDIZ MAHIR ALKAN

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...

2012
Marzieh Vafaee Mostafa M. Amini Seik Weng Ng

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...

2012
Rabindra Prasad Dhakal Tatsuya Oshima Yoshinari Baba

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...

2017
Thomas M Rookes Benedict M Gardner Gábor Balázs Matthew Gregson Floriana Tuna Ashley J Wooles Manfred Scheer Stephen T Liddle

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...

2009
Zhan-Xian Li Xia Li Li-Feng Zhang Ming-Ming Yu

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 ...

2017
Ioana Turcu Irina Zarafu Marcela Popa Mariana Carmen Chifiriuc Coralia Bleotu Daniela Culita Corneliu Ghica Petre Ionita

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...

Journal: :The Journal of chemical physics 2012
Paola Hurtado Francisco Gámez Said Hamad Bruno Martínez-Haya Jeffrey D Steill Jos Oomens

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...

Journal: :journal of physical & theoretical chemistry 2010
j. narafpour a. sadjadi

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...

2013
Truong Hong Hieu Le Tuan Anh Anatoly T. Soldatenkov Vasily G. Vasil’ev Victor N. Khrustalev

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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