The title compound, C24H29NO4, is the product of a Petrenko-Kritchenko condensation of 1,5-bis-(2-formyl-phen-oxy)-3-oxa-pentane, pentan-3-one and methyl-ammonium acetate in ethanol. The mol-ecule has mirror symmetry. The aza-14-crown-3 ether ring adopts a bowl conformation stabilized by a weak intra-molecular C-H⋯O hydrogen bond. The conformation of the C-O-C-C-O-C-C-O-C polyether chain is t-g...

The molecular complexes of 1,3,5-trithiane, (TT), tetrathia-8-crown-4, (TT8C4), and trithia-9-crown-3 , (TT9C3) with dihalogens in the ground state were investigated in the gas and dicholoromethane phases using B3LYP method and 6-31G** and 6-31+G** bases sets. In both TT and TT8C4 complexes, it is predicted that charge transfer takes place from the dihalogen to the thiacrown ether molecule; the...

In the title compound, 2CH(6)N(3) (+)·2Br(-)·C(12)H(24)O(6), the 18-crown-6 mol-ecule lies about an inversion center, whereas the guanidinium cation and bromide anion are in general positions. The guanidinium cations link with the bromide anions and the crown ether mol-ecules via N-H⋯O and N-H⋯Br hydrogen bonds, thus forming a three-dimensional network.

In the title compound, C(7)H(10)N(+)·BF(4) (-)·C(12)H(24)O(6), the proton-ated 4-methyl-anilinium cation inter-acts with 18-crown-6 forming a rotator-stator structure, (C(6)H(4)CH(3)NH(3) (+))(18-crown-6), through three bifurcated N-H⋯(O,O) hydrogen bonds between the ammonium groups of the cations (-NH(3)) and the O atoms of the crown ether mol-ecule. The BF(4) (-) anions, the methyl group and ...

The reaction of 4-fluoro-aniline hydro-chloride, 18-crown-6 and ferric chloride in methano-lic solution yields the title compound, (C(6)H(7)FN)[FeCl(4)]·C(12)H(24)O(6), which has an unusual supramolecular structure. N-H⋯O hydrogen-bonding inter-actions between the NH(3) (+) substituents of the 4-fluoro-anilinium cations and the O atoms of the crown ether mol-ecules result in a rotator-stator-li...

The compound (μ-3,3',3'',3'''-{[2,5,8,15,18,21-hexa-oxatricyclo-[20.4.0.0(9,14)]hexa-cosa-1(22),9,11,13,23,25-hexa-ene-11,12,24,25-tetra-yl]tetra-kis-(methyl-ene)}tetra-kis-(1-methyl-1H-imidazol-2-yl))bis-[(η(4)-cyclo-octa-1,4-diene)rhodium(I)] bis-(hexa-fluoridophosphate) acetonitrile sesquisolvate dihydrate, [Rh2(C8H12)2(C40H42N8O6)](PF6)2·1.5CH3CN·2H2O, crystallized from acetonitrile under a...

tin(ii)-ion-selective electrode consisting of dibenzo-18-crown-6 (db18c6) as an ionophore inpvc matrix was developed. the influences of membrane composition, selectivity, response time,reversibility and temperature on the electrode performance were investigated. the electrodeshowed a near nernstian response for sn2+ ions over a concentration range from 1.0× 10-6 – 1.0× 10-2 m with a slope of 27...

A silica-supported copper (Cu/SiO2) catalyst containing highly dispersed Cu nanoparticles was prepared via a crown-ether-assisted impregnation method. 12-crown-4-ether-assisted Cu/SiO2 outperformed several catalysts with various organic additives in the dehydrogenation of 2,3- and 1,4-butanediol. It found that catalytic activity, i.e., formation rate acetoin from 2,3-butanediol γ-butyrolactone ...