The title compound, C24H29NO4, is the product of a Petrenko-Kritchenko condensation of 1,5-bis-(2-formyl-phen-oxy)-3-oxa-pentane, pentan-3-one and methyl-ammonium acetate in ethanol. The mol-ecule has mirror symmetry. The aza-14-crown-3 ether ring adopts a bowl conformation stabilized by a weak intra-molecular C-H⋯O hydrogen bond. The conformation of the C-O-C-C-O-C-C-O-C polyether chain is t-g...

We report the first Hg(2+) selective hydrogelation by 4'-[4-(4-aminophenyl)phenyl]-2,2':6',2''-terpyridine. The gel showed remarkable response towards specific chemical agents such as benzo-18-crown-6 ether and K(+) which enabled extensive modulation of the gel morphology.

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...

Two new conjugated porphyrin-based systems (dimers 3 and 4) endowed with suitable crown ethers have been synthesized as receptors for a fullerene-ammonium salt derivative (1). Association constants in solution have been determined by UV-vis titration experiments in CH2Cl2 at room temperature. The designed hosts are able to associate up to two fullerene-based guest molecules and present associat...

The asymmetric unit of the title compound, [K(C(3)H(3)N(2))(C(12)H(24)O(6))], is composed of a potassium cation bonded to the six O atoms of a crown ether mol-ecule and the two N atoms of a pyrazolate anion. The K⋯O distances range from 2.8416 (8) to 3.0025 (8) Å, and the two K⋯N distances are 2.7441 (11) and 2.7654 (11) Å. The K cation is displaced by 0.8437 (4) Å from the best plane through t...

we found that dibenzo-18-crown-6 (db18c6) can be used as an ionophore to make a tin (ii)-ionselectivemembrane electrode. the electrode exhibits a near nernstian response for sn2+ ions over aconcentration range from 1.0× 10-6 – 1.0× 10-2 m with a slope of 27.5 ± 0.6 mv per concentration decadein an acidic solution (ph=1). the limit of detection was 8.0× 10-7 m. it has a response time of < 20s an...

The title compound, C(24)H(26)N(4)O(4), is a diaza-crown ether encompassing linked phenylpyrazolyl and benzimidazole units that contribute five atoms to the 16-atom ring. The two planar phenylpyrazolyl and benzimidazole units are aligned at an angle of 66.4 (1)°. The carbonyl O atom of the benzimidazole unit is directed away from the middle of the ring.

'Conventional' (-)-sparteine adducts of lithium and sodium 1,1,1,3,3,3-hexamethyldisilazide (HMDS) were prepared and characterised, along with an unexpected and 'unconventional' hydroxyl-incorporated sodium sodiate, [(-)-sparteine x Na(mu-HMDS)Na x (-)-sparteine](+)[Na(4)(mu-HMDS)(4)(OH)](-)--the complex anion of which is the first inverse crown ether anion.

To probe the influence of electrostatic interactions on the mesomorphic self-assembly and phase behaviour of hybrid liquid crystals a series of crown ether/tyrosine hybrid systems was prepared by Steglich esterification of alkyl N-(tert-butoxycarbonyl)-l-tyrosinates with 4-carboxybenzo[15]crown-5 and 4-carboxybenzo[18]crown-6. The obtained derivatives allowed further manipulations at the NH fun...

tin(ii)-ion-selective electrode consisting of dibenzo-18-crown-6 (db18c6) as an ionophore inpvc matrix was developed. the influences of membrane composition, selectivity, response time,reversibility and temperature on the electrode performance were investigated. the electrodeshowed a near nernstian response for sn2+ ions over a concentration range from 1.0× 10-6 – 1.0× 10-2 m with a slope of 27...