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.

Complexes of 18-crown-6 with alkali-metal cations (Na', K', and Rb'), urea, and the uncomplexed crown ether were studied in V ~ C U O with the molecular dynamics method. Conformational data from these calculations (simulation times in the range from 6-15 ns) was compared with information from the Cambridge Structural Database. Despite the differences in condition between the simulations and the...

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...

In the title compound, [CuBr(2)(H(2)O)(2)]·C(12)H(24)O(6)·2H(2)O, the Cu(II) atom, which is situated on an inversion centre and has a slightly distorted square-planar geometry, and the two coordinated water mol-ecules are linked to the 18-crown-6 macrocycles by O-H⋯O hydrogen bonds. The water mol-ecule of crystallization further links the metal complex and the crown ether macrocycles into a cha...

Supramolecular chemistry explores the effects of non-covalent interactions on the self-organization of matter. One strand of supramolecular enquiry has led to the creation of a variety of structurally and topologically nontrivial mechanically interlocked molecules. In the pursuit of deepening the complexity of such structures we report herein the formation of a new class of mechanically interlo...

The reaction of 4-bromo-3-methyl-anilinium perchlorate and 18-crown-6 in methanol solution yielded the title compound, C(7)H(9)BrN(+)·ClO(4) (-)·C(12)H(24)O(6). The protonated 4-bromo-3-methyl-amine unit contains one -NH(3) (+) substituent, resulting in a 1:1 supra-molecular rotator-stator structure, (C(7)H(9)Br-NH(3) (+))(18-crown-6), through three bifurcated N-H⋯(O,O) hydrogen bonds between t...