title: Host-guest complexes between cucurbit[n]urils and acetanilides having aminopropyl units.
abstract: 2-(Propylamino)acetamide of aniline (1a), and bis-2-(propylamino)acetamide of ortho- (1b) and para-(1c) phenylenediamine form host-guest complexes with CB[6], CB[7] and CB[8] as evidenced by the variations in the (1)H NMR spectroscopy chemical shifts and observation in MALDI-TOF-MS and ESI-MS of ions at the corresponding mass. Binding constants for the 1:1 complexes were estimated from fluorescence titrations and were in the range 10(5)-10(6)M(-1). Models based on molecular mechanics for these supramolecular complexes are provided. In spite of the different geometries arising from the ortho- or para-substitution, phenylenediamides form complexes of similar strength in which the hydrophobic alkyl chains are accommodated inside the host cavity. Formation of these host-guest complexes in the solid state was also achieved by modifying an aminopropyl silica with chloroacetanilides and preparing three silica having analogues of compounds 1a-c anchored to the solid particles. Titrations showed, however, that these solids can adsorb a large percentage of CBs by unselective interactions that are not related to the formation of inclusion complexes.
authors.affiliation: Instituto de Tecnología Química CSIC-UPV and Departamento de Química, Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Buaki-Sogo
authors.forename: Pedro
authors.initials: P
authors.lastname: Montes-Navajas
authors.forename: Mercedes
authors.initials: M
authors.lastname: Alvaro
authors.forename: Hermenegildo
authors.initials: H
authors.lastname: Garcia
mesh_terms: D000083:Acetanilides / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D001952:Bridged-Ring Compounds / Q000737:chemistry*; D007477:Ions; D008958:Models, Molecular; D010655:Phenylenediamines / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000083:Acetanilides; D000814:Aniline Compounds; D001952:Bridged-Ring Compounds; D007477:Ions; D010655:Phenylenediamines; D012822:Silicon Dioxide; C023650:aniline