Lower Rim Carboxylic Acids

Carboxylic acids of the general structure 264a differ from the esters, ketones, and amides in having ionizable groups, the values in MeOH for the 

Ketone 265a Carboxylic Ester 264b Carboxamide 266a 

Although the calixarene carboxylic acids form complexes with some of the alkali metal cations, the fact that they have an even greater capacity for alkaline earth cations was first realized in the mid 1980s and subsequently studied in some detail. As a consequence of their greater charge the alkaline 

Shiratsuchi, K. Inoue, K. Goto, M. Nakashio, F. Shinkai, S. Nagasaki, T. Solvent 

Ludvig, R, Inoue, K. Yamato, T. Solvent Extr. Ion Exch. 1993, 11, 311. 

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