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Alkali and alkaline‐earth metal cation complexation and transport properties by tetraphenyl ketone of p ‐ tert ‐butyldihomooxacalix[4]arene
Author(s) -
Marcos Paula M.,
Ascenso José R.,
Segurado Manuel A. P.,
Pereira J. L. C.
Publication year - 1999
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/(sici)1099-1395(199909)12:9<695::aid-poc181>3.0.co;2-t
Subject(s) - chemistry , dichloromethane , alkaline earth metal , ketone , alkali metal , acetonitrile , aqueous solution , inorganic chemistry , metal , extraction (chemistry) , solvent , organic chemistry
The tetraphenyl ketone of p ‐ tert ‐butyldihomooxacalix[4]arene ( 2 ) was synthesized for the first time. This derivative possesses the cone conformation in solution at room temperature, which was confirmed by NMR measurements ( 1 H, 13 C and NOE 1D). Extraction studies with metal picrates from neutral aqueous solution into dichloromethane, transport experiments with metal picrates through a dichloromethane membrane and stability constant measurements by UV absorption spectroscopy in methanol and acetonitrile were performed to evaluate the binding ability of ketone 2 towards alkali and alkaline earth metal cations. The tetraphenylketone of p ‐ tert ‐butylcalix[4]arene ( 3 ) was also studied, and the results for the two derivatives were compared. Compound 2 shows a preference for K + and Ba 2+ cations, being selective only in the alkaline earth metal cation series. Compound 3 is a stronger binder than 2 , but is a weaker extractant. Both show transport rates that are not proportional to complex stability or to extraction efficiency. Ketone 2 can be characterized as a selective receptor. Copyright © 1999 John Wiley & Sons, Ltd.