A novel synergistic extraction system was investigated for the possible selective separation of light lanthanoids using an ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, as an extraction solvent and 2-thenoyltrifluoroacetone and 18-crown-6 as extractants. Trivalent lanthanum was efficiently extracted as a cationic ternary complex by the cation-exchange process, wh...

Hydrogels containing benzo-18-crown-6 were used to modify microcantilevers for measurements of the concentration of Pb2+ in aqueous solutions. These microcantilevers undergo bending deflection upon exposure to solutions containing various Pb2+ concentrations as the result of a swelling of the hydrogels. It was found that a concentration of 10(-6) M Pb2+ can be detected using this technology. Ot...

Experimental (IR and Raman) and theoretical (Kohn-Sham calculations) methods are used in a combined analysis aimed at refining the available structural data concerning the molecular guests in channels formed by stacked dibenzo-18-crown-6 (DB18C6) crown ether. The calculations are performed for a simplified model comprising isolated DB18C6 unit and its complexes with either H2O or H3O+ guests, w...

The title compound (systematic name: cis-anti-cis-2,5,8,15,18,21-hexa-oxatri-cyclo-[20.4.0.0(9,14)]hexa-cosane aceto-nitrile disolvate), C20H36O6·2CH3CN, crystallizes from an aceto-nitrile solution of di-cyclo-hexane-18-crown-6 on evaporation. The mol-ecule is arranged around a center of symmetry with half the crown ether mol-ecule and one mol-ecule of aceto-nitrile symmetry independent. All O-...

Recently we reported the profound effects of second-sphere crown ether binding upon the redox energetics and intervalence spectroscopy of selected mixed-valence (Crowd metal complex associatino is driven primarily by ether oxygen/ ammine hydrogen interactions, where the H-bond-donating capability of NH3 is greatly enhanced by coordination to a transition-metal cation.) For delocalized species s...

By employing different diimine complexes and a naphthanoimidazolate (L(1)) or benzoimidazolate (L(2)) anion ligand as linker, a series of trimetallo-macrocycles have been synthesized through a directed self-assembly approach that involves spontaneous deprotonation of the ligands in aqueous solution. Some compounds, namely, [M(3)L(3)](NO(3))(3) (M = (18-crown-6-phen)Pt, 1 or 7; (15-crown-5-phen)...

18-Crown-6 ether (18C6) is evaluated as a shift reagent for multidimensional ion mobility spectrometry-mass spectrometry (IMS-IMS-MS) analyses of tryptic protein digests. In this approach, 18C6 is spiked into the solution-phase mixture and noncovalent peptide-crown ion complexes are formed by electrospraying the mixture into the gas phase. After an initial mobility separation in the first IMS d...

The addition of 1 equiv of KSCPh3 to [L(R)NiCl] (L(R) = {(2,6-iPr2C6H3)NC(R)}2CH; R = Me, tBu) in C6H6 results in the formation of [L(R)Ni(SCPh3)] (1: R = Me; 2: R = tBu) in good yields. Subsequent reduction of 1 and 2 with 2 equiv of KC8 in cold (-25 °C) Et2O in the presence of 2 equiv of 18-crown-6 results in the formation of "masked" terminal Ni(II) sulfides, [K(18-crown-6)][L(R)Ni(S)] (3: R...

Crown ether complexation solubilizes organic and inorganic salts in nonpolar media. Induction of crystallization from such solutions can result in crystallization of the free salt rather than the complex. This affords the opportunity to examine solvent effects on the crystallization of salts and other polar materials, leading to the modification of crystal shape and lattice. This approach, whic...