investigate formation constant of some amino acids by p-sulphonato-calix (4) arene in aqueous solution

Authors

noushin osouleddini

department of applied chemistry, faculty of pharmaceutical chemistry, pharmaceutical sciences branch, islamic azad university, tehran, iran

abstract

the formation constants (log k), of the complexes formed between a number of amino acids(glycine , l-valine and l-alanine) with p-sulfonatocalix [4] arene at varying temperatures (25± 0.1to 65 ± 0.1 °c) in aqueous solutions and at natural ph of p-sulphonato-calix [4] arene (ph=3.2) bymeans of uv-vis spectrophotometeric technique have been investigated. at this ph the guestmolecule is in its cationic and zwitterionic forms. the results revealed that the host is q ui t ecapable of complexing with the guest in 1:1 guest-to-host ratio. regarding the formation constantvalues, the binding selectivity of the host towards the guests proves in the order (alanine > valine >glycine). the thermodynamic parameters have been assessed and interpreted in matters of thesignificance of the various interactions responsible for the complexation. a roughly linear relationshipbetween bho and tbso has been observed for the studied complexes and it is discussed.

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Journal title:
journal of physical and theoretical chemistry

جلد ۱۲، شماره ۴، صفحات ۳۰۷-۳۱۴

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