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Ion Recognition at the Interface of Self‐Assembled Monolayers (SAMs) of Bis‐Thioctic Ester Derivatives of Oligo(ethyleneglycols)
Author(s) -
Bandyopadhyay Krisanu,
Liu ShengGao,
Liu Haiying,
Echegoyen Luis
Publication year - 2000
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20001201)6:23<4385::aid-chem4385>3.0.co;2-7
Subject(s) - chemistry , monolayer , self assembled monolayer , aqueous solution , ion , crown ether , thioctic acid , ether , polyethylene glycol , self assembly , polymer chemistry , inorganic chemistry , stereochemistry , organic chemistry , biochemistry , lipoic acid , antioxidant
Self‐assembled monolayers (SAMs) of bis‐thioctic ester derivatives of oligoethylene glycols were prepared. When the number of (−CH 2 −CH 2 −O−) n units in these podands was either five or six, the corresponding SAMs showed ion binding properties and selectivities similar to those exhibited by 15‐crown‐5 or 18‐crown‐6 in aqueous solution, respectively. Impedance data for the SAMs as a function of metal ion concentrations were fitted by using a Langmuir isotherm to determine the association constants ( K a ) with the different ions. The SAM derived from the n =5 compound is selective for Na + while that with n =6 is selective for K + . Results presented here confirm the formation of ion recognition domains during self‐assembly of acyclic polyethylene glycol derivatives on gold surfaces; this suggests that surface‐confined pseudocrown ether structures are formed.