An unusual crossed dimer motif is present in the solid state infinite TCNQ˙ − columns of bis-12-crown-4 complexes Li and NaTCNQ.

deuterating reagent ultimately becomes detached from the complex, with the net effect of one hydrogen atom being replaced with a deuterium atom. This H/D exchange process may repeat multiple times in the gas phase. Other pathways that are independent of the charge site and involve the interaction of the deuterating reagent directly with the labile hydrogen atom are typically higher in energy an...

Crown ethers 12-crown-4 (12C4), benzo-15-crown-5 (B15C5), 18-crown-6 (18C6), nitrobenzo-18-crown-6 (NB18C6) dibenzo-18-crown-6 (DB18C6) and dicyclohexyl-18-crown-6 (DC18C6), dissolved in dichloromethane, are able to form oxonium-ion complexes in contact with aqueous sulfuric and hydrochloric acid solutions. This ability allows the transfer of Cr(VI) oxanions from the acid media, through an ...

On heating the hydrated complexes 18-Crown[6].M[H(2)PO(4)].xH(2)O (x= 2 for M = K, Rb; x= 1.5 for M = Cs), quantitatively prepared by mechanical mixing of crystalline 18-Crown[6] and M[H(2)PO(4)], to ca. 60 degrees C, water loss takes place, accompanied by the extrusion of the crown ether from the crystalline complex and followed by reconstruction of the inorganic phase M[H(2)PO(4)](M = K, Rb, ...

a competitive spectrophotometric method has been used for the study of complexation between cu2+, zn2+ and cd2+ (m) and 18-crown-6(18c6, b) in methanol using 4-(2-thiazolylazo) resorcinol (tar, hl) as the colorimetric complexant. absorption spectra of the species in the m-tar-18 c6 system at a various concentrations of 18c6 showed no formation of ternary complex, mlb, and the stoichiometry of t...

A series of supramolecular complexes of various cytochrome c proteins with 18-crown-6 derivatives behave as cold-active synzymes in the H2O2 oxidation of racemic sulfoxides. This interesting behavior contrasts with native functionality, where the employed proteins act as electron transfer carriers. ESI-MS. UV, CD, and Raman spectroscopic characterizations reveal that four or five 18-crown-6 mol...

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...

Conformational restriction imposed upon Ru(bpy)32+ crown ether complexes by metal ion binding leads to enhanced luminescence.

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...

• The discovery of the first crown ether is described. Forty-seven other aromatic and saturated polyethers were synthesized and their properties determined. Many form stable crystalline complexes with alkali and alkaline earth salts. Some saturated crown ethers solubilize potassium hydroxide and permanganate in aromatic hydrocarbons, EThe SC!5 indicates that this paper has been cited in over 1,...