Solubilization by Phosphate Esters of Calix [4] resorcinarenes Bearing Four Alkyl Side Chains

Abstract

Phosphate esters of calix[4]resorcinarenes each bearing four alkyl side chains([4]Ar5P-R n ) were evaluated as a solubilizing agent and usefulness for dyeing. [4]Ar5P-R n was oriented toward the surface of water or benzene-water interface. [4]Ar5P-R 8 lessened surface tension and [4]Ar5P-R 16 reduced interfacial tension. [4]Ar5P-R n showed high solubilization for organic compounds such as benzene, β-naphthol, and dye, particularly so at high concentrations near cmc. The solubilization capacity by [4]Ar5P-R n decreased in greater size of the organic compounds, as well as alkyl chain length in [4]Ar5P-R n had effect on solubilization capacity for the organic compounds. [4]Ar5P-R 16 was the most effective solubilizing agent, i. 500-fold molar benzene was dissolved in [4jAr5P-R 16 at a solubility limit of 1x10 -4 M. Dyes also dissolved in [4]Ar5P-R n solution and acetate rayon could be dyed effectively using [4]Ar5P-R 8 to assist the dyeing. The solubilization for the organic compounds may possibly be due to the formation of finely dispersed colloidal particles or a microemulsion.