Jin CM, Shreeve JM. Bridged Di(alkyl- and 4,4,4-trifluorobutylimidazolium) Quaternary Salts Based on p-tert-Butylcalix[4]arene.
Inorg Chem 2004;
43:7532-8. [PMID:
15530104 DOI:
10.1021/ic049041c]
[Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Di(alkyl- and 4,4,4-trifluorobutylimidazolium) quaternary halides of p-tert-butylcalix[4]arene, 5a-8a and 11a, were prepared and characterized. Metathetical reactions of these compounds with LiN(SO(2)CF(3))(2) and KPF(6) in methanol and water gave the corresponding new quaternary salts 5b-8b and 11b and 5c-8c and 11c, respectively, with high thermal stabilities. Compounds 5a-d, 6b, and 11a-c exhibit melting points <100 degrees C. On the basis of (1)H NMR and (13)C NMR spectral measurements, all of the new quaternary calix[4]arene salts were found to exist in a cone conformation. (1)H NMR titration experiments and electrospray MS spectra support the encapsulation of K(+) in the ionophoric cavity of 11c.
Collapse