The stoicheiometrically 1:1 adduct of 1,4,7,10,13,16-hexaoxa-cyclooctadecane with m-nitroaniline, C18H30N2O8, Mr = 402.45, crystallises from toluene in red-orange prisms, (probable) space group P i , a = 801.8(3), b = 920.4(3), c = 1403.3(4) pm, a = 80.40(4), ß = 79.79(4), y = 85.95(3)°, V = 1.07910 nm3, Z = 2, dcaic. = 1.238 Mgm~3. Structure refinement converged at R = 0.060 (Rw = 0.002) for 2...

Novel dual-pipet electrodes prepared by pulling borosilicate theta-tubing are described. Three types of electrochemical experiments employing such devices include the following: (1) generation/collection experiments in which ions are ejected from one of two micropipets ("generator") into the external solution and collected at the second pipet ("collector"), (2) measurements of ohmic current-vol...

Molecular-dynamics simulations of crystalline 18crown-6 have been performed in a study of the apparent thermal shortening of covalent bonds observed in crystal structures. At 100 K, a shortening of 0.006 _+ 0.001 A for C----C and C----O bonds was obtained. This result was found to be independent of details of the force field and the simulation. There was agreement between computational and expe...

A simple and sensitive extraction-spectrophotometric method for rapid and accurate determination of benzocaine in pure and dosage forms was developed. Benzocaine was effectively extracted as a 1:1 ion pair complex with dicyclohexyl18-crown-6 and calmagite in acidic media into chloroform, followed by spectrophotometric determination at 486 nm. Molar absorptivity of the ternary complex at this wa...

Single-crystals X-ray structure analysis of very thermally labile and moisture sensitive ammoniate crystals of [K0.28Rb7.72Si9Ni(CO)2]2·16NH3 show the presence of the very rarely observed nickel-silicide complex [{Ni(CO)2}2(μ-Si9)2]8−, which was up to now only known in the 18-crown-6 involving solid [Rb@18-crown-6)]2[K@18-crown6)]2Rb4[{Ni(CO)2}2(μ-Si9)2]·22NH3. This shows that, like already kno...

The title compound, C(2)H(2)·C(12)H(24)O(6)·2NH(3), was formed by co-crystallization of 18-crown-6 and acetyl-ene in liquid ammonia. The 18-crown-6 mol-ecule has threefold rotoinversion symmetry. The acteylene mol-ecule lies on the threefold axis and the whole mol-ecule is generated by an inversion center. The two ammonia mol-ecules are also located on the threefold axis and are related by inve...

In the title compound, [Zn(C44H28N4)]·C12H24O6, the Zn(II) ion lies on an inversion center and the asymmetric unit contains one half of a Zn(TPP) complex (TPP = 5,10,15,20-tetra-phenyl-porphyrin dianion) and one half of a centrosymmetric 18-crown-6 mol-ecule. The Zn(TPP) complex exhibits a nearly planar conformation of the porphyrin core [maximum deviation = 0.106 (2) Å] with an average Zn-N di...

18-Crown-6, one of the most relevant crown ethers, and sodium cholate, a steroidal surfactant classified as a natural bile salt, are components of a novel, synthesized coordination complex: 18-crown-6-sodium cholate (18C6·NaCh). Like crown ethers, bile salts act as building blocks in supramolecular chemistry to design new functionalized materials with a desired structure and properties. In orde...

Aiming at a fundamental understanding of the synergistic effects different additives on electrochemical Mg deposition/dissolution in an ionic liquid, we have systematically investigated these processes combined and theoretical study, using 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMP-TFSI) as solvent cyclic ether (18-crown-6) magnesium borohydride additives. Both crown ...

In the title compound, C(3)H(12)N(2) (2+)·2ClO(4) (-)·2C(12)H(24)O(6), the central C atom of the propane-1,3-diammonium cation is located on a twofold rotation axis and the two terminal -NH(3) groups insert into the crown rings through N-H⋯O hydrogen bonding, resulting in the formation of a 1:2 supra-molecular [(C(3)H(12)N(2))·(C(12)H(24)O(6))(2)](+) complex. The perchlorate anion links with th...