The charged-component complexes H3O+•18-crown-6.CF3SO3−, H3O+•18-crown-6.SbF6−, and (H3O+•18-crown-6)2•PtCl62− have been isolated and studied by infrared and Raman spectroscopy, along with the previously reported H3O+•18-crown-6•C1O4− and H3O+•18-crown-6•PF6− adducts. Also synthesized were the corresponding derivatives with BF4− and PtCl62− anions, using dicyclohexano-18-crown-6 as the host for the hydronium ion.

. Can. J. Chem. 60,853 (1982). The macrocyclic ether 1,4,7,10,13,16-hexaoxaoctadecane (18-crown-6) has the remarkable property of being able to transfer the hydronium (H,O+) ion from an aqueous solution to an organic medium. This property has been used to synthetize a 1:l stoichiometric complex of this ether with hydronium tetrafluoroborate. This complex is very stable (mp 145°C) and dissolves readily, without decomposition, in solvents such as CHCI,. The presence of the H 3 0 + and BF4-ions in the complex has been confirmed by chemical analysis, and by IH nmr, Raman, and ir spectroscopy. The vibrational spectraindicate that a conformational change of the crown ether takes place in the complex over the temperature range -50°C to -100°C. The symmetry of the crown ether, which appears to be relatively high at room temperature, is considerably reduced below the transition temperature.ROBERT CH~NEVERT, AND& RODRIGUE, MARIE PIGEON-GOSSELIN et RODRIGUE SAVOIE. Can. J. Chem. 60,853 (1982). L'ether macrocyclique 1,4,7,10,13,16-hexaoxaoctad&cane (18-crown-6)

High resolution 13C CPMAS spectra for three configurationally isomeric dicyclohexyl-18-crown-6 ethers and three complexes derived therefrom are presented. Spectra are consistent with conformationally locked crown ether structures at 298 K. Data are discussed in terms of the symmetry properties of the macrocycles and stereochemical effects on 13C chemical shifts in the solid phase. For the complex of 18-crown-6 with NaSCN and H2O, a single line is observed at 298 K. Temperature reduction removes the chemical shift averaging as the different torsional angles of the solid crown ether undergo distortions that become slow on the nuclear magnetic resonance timescale.

. Can. J. Chem. 64, 816 (1986). The crystal structures of the 1 :2 host:guest complexes of dicyclohexano-18-crown-6 (isomer B) with potassium phenoxide and dicyclohexano-18-crown-6 (isomer A) with sodium phenoxide have been determined. The potassium phenoxide complex crystallizes in space group PI with a = 10.023(2), b = 11.238(2), c = 7.546(2) A, cx = 95.73(2), P = 103.04(2), y = 92.03(2)", and Z = 1. The sodiumphenoxide complex crystallizes in space group P2,/n with a = 19.185(12), b = 13.266(5), c = 13.038(5) A, P = 96.55(4)", and Z = 4. Both structures were solved by direct methods and refined by full matrix least-squares calculations to a residual, R , of 0.035. The host conformation as well as the metal cation coordination differ considerably in the two structures. In the potassium phenoxide complex, the two cations are related by symmetry and have, consequently, the same chemical environment. Each potassium is located approximately halfway between the plane formed by the crown ether oxygens and the phenoxide anions and is coordinated to four of the crown oxygens and to two phenoxide oxygens. The oxygens of the crown are found to outline an elliptical cavity and to lie approximately in a plane. In the sodium phenoxide complex, the two sodiums have different crystallographic and chemical environments. One sodium is coordinated to the six hexaether oxygens, withdistances ranging from 2.36 to 2.84 A, and to one of the phenoxide oxygens. The other sodium is coordinated to only one of the crown oxygens and to three of the phenoxide oxygens. The hexaether adopts a highly irregular conformation. affinCes par la mtthode des moindres carrts (matrice entiere) jusqu'a des valeurs rCsiduelles de R de 0,035. La conformation de la molCcule hate ainsi que la coordination du cation mitallique different considtrablement dans les deux structures. Dans le complexe du phknolate de potassium, les deux cations sont relits par de la symttrie et ont donc des environnements chimiques semblables. Chaque potassium est situt approximativement a mi-chemin entre le plan form6 par les oxygknes de la couronne et celui des anions phtnolates et chacun est coordonnk a quatre oxygknes de la couronne et a deux oxygknes des phenolates. On a trouvC que les oxygknes de la couronne foment le contour d'une cavitt ellipsoidale et qu'ils se retrouvent approximativement dans un plan. Dans le complexe du phCnolate de sodium, les deux cations de sodium se trouvent dans des environnements cristallographiques ainsi que chimiques qui sont difftrents. Un des cations de sodium est coordonnC aux six oxygknes de l'tther, avec des distances variant de 2,36 a 2,84 A, et a l'un des oxygknes des phenolates. L'autre sodium est coordonnt a un seul des oxygknes de la couronne et a trois oxygtnes des phCnolates. La conformation de la couronne est hautement irrtguliere.[Traduit par la revue] Introduction .Of the crown ethers, 18-crown-6 is probably the most extensively characterized. Nuclear magnetic resonance (nrnr), infrared (ir), X-ray diffraction studies, as well ...

The title complex crystallizes in the space group Pcab with a = 16.019(7), b = 19.62(1), c = 15.847(5) A, and Z = 8. The structure was solved by direct methods and refined by full matrix least-quares calculations to a residual, R , of 0.083. The monomeric structure lacks a true centre of symmetry although the two lithiums have similar chemical environments. Each lithium cation is coordinated to three different oxygens of the hexaether and to both phenoxide oxygens. The hexaether is slightly elongated allowing both Li(1) and Li(2) to lie in the cavity formed by the crown with values of -0.077 and0.074 A, respectively, out of the plane approximated by the six oxygens. Both cations are stron ly associated with the phenol moieties. The distances between the lithium and the phenoxide oxygens range from 1.859-1.893 ! , while distances of 1.940-2.420 A are found with the ether oxygens. The L i ( l t L i ( 2 ) distance is found to be relatively short at 2.35 (2) A.Evidence for motion in the 18-crown-6 portion of the solid complex has been obtained from I3C CPMAS NMR spectroscopy. At 298 K, a dipolar washout phenomenon occurs since the motional correlation times are of the order of the inverse of the 'H decoupling field amplitude. At lower temperatures, the motion becomes slow enough to permit resolution of the chemical shift differences of unique carbon sites of the crown ether. Consistent with the X-ray analysis, only five resonances are evident for the phenoxide carbons, indicating that the two aromatic rings are nearly equivalent in their crystallographic environment. The solution 13C spectrum shows only five resonances in total down to 188 K indicative of rapid conformational averaging of all the 18-crown-6 carbon resonances and rapid rotation about the 0-phenyl bond. A et Z = 8. On a rCsolu la structure par des mCthodes directes et on l'a affinCe par la mCthode des moindres carrts jusqu'h une valeur de R = 0,083. La structure monomkre ne posskde pas de vrai centre de symCtrie m&me si les deux atomes de lithium se trouvent dans des environnement chimiques semblables. Chaque cation lithium est coordonnC 5 trois oxygknes difftrents de I'hexaCther et aux deux groupements hCnolates. L'hexatther est partiellement allonge et les deux Li (1) En se basant sur des donnies de spectroscopie rrnn CPMAS due 13c, on a pu mettre en evidence un mouvement de 1'Cther 18-couronne-6. A 298 K, il se produit un phCnomkne d'annulation dipolaire qui rtsulte du fait que les temps de corrClation des mouvements sont du m&me ordre de grandeur que l'inverse de l'amplitude du champ de decouplage du 'H. A des temperatures plus basses, le mouvement devient suffisamrnent lent pour permettre la rksolution des differences dans les diplacements chimiques des sites uniques des carbones de 1'Cther couronne. En accord avec l'analyse des rayons-X, on n'obsewe que cinq bandes de resonance pour les carbones du phCnolate; ces rtsultats indiquent que les deux cycles aromatiques sont pratiquement Cquivalents dans leur environnement cristallographique. Au tota...