title: Tri- and pentacalix[4]pyrroles: synthesis, characterization and their use in the extraction of halide salts.
abstract: Calixpyrrole-based oligomeric compounds were synthesized by "click chemistry" from the corresponding alkyne- and azide-functionalized calix[4]pyrroles. Calix[4]pyrrole 3, possessing an alkyne functional group, was prepared through a mixed condensation of pyrrole with acetone and but-3-ynyl 4-oxopentanoate. Another alkyne-group-containing calix[4]pyrrole 5 was obtained by treatment of 4'-hydroxyphenyl-functionalized calixpyrrole 4 with propargyl bromide. Tetrakis(azidopentyl)-functionalized calix[4]pyrrole 7 was synthesized by reacting NaN(3)  with tetrabromopentyltetraethylcalix[4]pyrrole 6, which was prepared through a condensation reaction of pyrrole and 7-bromohept-2-one. Oligomeric calixpyrrole compounds were found to be capable of extracting tetrabutylammonium chloride and fluoride salts from aqueous media. Extraction abilities of the oligomeric compounds were monitored by NMR and UV/Vis spectroscopy and thermogravimetric analysis.
authors.affiliation: Istanbul Technical University, Department of Chemistry, Maslak 34469 Istanbul, Turkey. aydoganab@itu.edu.tr
authors.forename: Abdullah
authors.initials: A
authors.lastname: Aydogan
authors.forename: Ahmet
authors.initials: A
authors.lastname: Akar
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D006846:Hydrocarbons, Halogenated / Q000032:analysis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000737:chemistry*; D012492:Salts; D014867:Water / Q000737:chemistry
chemical_list: D006846:Hydrocarbons, Halogenated; D011758:Pyrroles; D000644:Quaternary Ammonium Compounds; D012492:Salts; D014867:Water; D047250:Calixarenes; C009405:tetrabutylammonium