GNPs (gold nanoparticles) as an eye-catching sensor rely on the high extinction coefficients and the shift of the surface plasmon band which signals the disperse-to-aggregate transformation. The selectivity of the sensors is dictated by the surface functionality whose density presumably has a positive correlation with the sensitivity toward the targeted analyte. To improve the analytical perfor...

The synthesis of some thio-oxocrown ether ligands, B1 (1,4-dithio-12-crown-4), B2 (1,7-dithio-12-crown-4), B3 (1,7-dithio-15-Crown-5), B4 (1,7-dithio-18-crown-6), B5 (1,10-dithio-18-crown-6), B6 (1,10-dithio-21-crown-7), under mild conditions, were reported. The ligands were characterized by FT-IR, H NMR and GC-MS spectroscopy. The formation of 1:1 ligand complexes with a variety of metal salts...

Crown ethers are small, cyclic polyethers that have found wide-spread use in phase-transfer catalysis and, to a certain degree, in protein chemistry. Crown ethers readily bind metallic and organic cations, including positively charged amino acid side chains. We elucidated the crystal structures of several protein-crown ether co-crystals grown in the presence of 18-crown-6. We then employed biop...

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...

Shape-persistent conjugated macrocycles are challenging synthetic targets with interesting properties and potential for a number of applications. In contrast to the standard kinetic approaches to macrocycles, reversible Schiff-base condensation offers a one-step, thermodynamic route to large macrocycles. These macrocycles, which feature “salen”-type coordination environments and an interior tha...

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(6)H(7)ClN(+)·ClO(4) (-)·C(12)H(24)O(6), the cation forms a 1:1 complex with the crown ether, viz [C(6)H(7)ClN-(18-crown-6)](+), in which the -NH(3) (+) unit nests in the crown and inter-acts with it through bifurcated N-H⋯O hydrogen bonding. All constituents of the structure have crystallographically imposed mirror symmetry except for the H atoms of the -NH(3) (+) group...

The preparation and assessment of a crown ether covalently grafted onto MoS2 as an ion-selective electrode for sodium ions in biological fluids is presented.

The mobility of coordinated methanol in the complex [Co(II)(Benzo[ 15]crown-5)(CH3OH)2] + was studied in nitromethane. The methanol exchange mechanism tends to an associative nature with an increasing amount of methanol in the solutions as can be deduced from the activation entropy. All activation data can be combined in an isokinetic relationship which is also valid for the respective complex ...

A cobalt aquo-hydroxo complex of a ditopic Schiff-base pyrrole-crown ether macrocycle has been prepared and forms a rigid Pacman-clefted structure that assembles through hydrogen-bonding into a hexagonal wheel motif in the solid state.