A rigid octacationic tetraviologen-based cyclophane, (8+), is reported. It possesses a highly electron-deficient rectangular cavity with a length of 23 Å and width of 6.1 Å and is capable of encapsulating either two small π-aromatic guest molecules, such as PhMe and PhCl, simultaneously, or one large molecule, e.g., bis-1,5-dinaphtho[50]crown-14.

Self-assembly of a tribenzo-27-crown-9 ether functionalized with six terpyridines generated (85%) an expanded tetrahedral structure comprised of four independent triangular surfaces interlinked by crown ether vertices.

In the title compound, C(7)H(10)N(+)·ClO(4) (-)·C(12)H(24)O(6), the 4-methyl-anilinium cation inter-acts with an 18-crown-6 mol-ecule forming a rotator-stator-like structure through bifurcated N-H⋯(O,O) hydrogen bonds between the ammonium group of the cation and the O atoms of the crown ether mol-ecule. All three components of the structure possess mirror symmetry. The benzene ring is inclined ...

A convenient synthesis of 3,4-didehydroretinal was developed. The Horner-Emmons reaction between 3,4-didehydro-beta-ionone and diphenyl phosphonate in the presence of crown ether gave the retinonitrile as an isomeric mixture, in which the newly produced double bond was predominantly 11Z-form. After separation of the 11Z-form retinonitrile, it was converted into the corresponding retinal in good...

The first hybrid crown ether with two adjacent disilane fragments was synthesized through reaction of O(Si2Me4Cl)2 (3) with O(C2H4OH)2. By means of DFT calculations, the complexation ability of 1,2,4,5-tetrasila[12]crown-4 (7) towards Li+ was determined to be considerably higher compared to [12]crown-4.

Sixteen lipophilic N-(X)sulfonyl carbamoyl lariat ethers with polyether ring sizes of 12-crown-4, 14-crown-4, 15-crown-5, and 18-crown-6 are utilized for competitive alkali metal cation extractions from aqueous solutions into chloroform. Variation of the electron-withdrawing properties of X in the series of methyl, phenyl, 4-nitrophenyl, and trifluoromethyl allows the influence of the acidity o...

Extending to transition metals, the class of compounds known as inverse crown ethers, two mixed alkali metal-manganese(II) amide ring compounds with oxo cores have been synthesised and crystallographically characterised, together with an oxo-free alkyl-amido precursor.