title: Fourfold [2]rotaxanes based on calix[4]arenes.
abstract: Tetraurea calix[4]arenes with four loops form exclusively heterodimers with open-chain urea calix[4]arenes when they are dissolved in aprotic solvents. These assemblies can be considered as pseudorotaxanes. If open-chain tetraureas ending with maleic imide functions are used, their Diels-Alder reaction with 1,4,5,8-tetrapentoxyanthracene leads to tetra[2]rotaxanes which cannot be split into the single calixarene parts by hydrogen bond breaking solvents.
authors.affiliation: Abteilung Lehramt Chemie, Fachbereich Chemie, Pharmazie und Geowissenschaften, Johannes Gutenberg-Universität, 55099 Mainz, Germany.
authors.forename: Carmine
authors.initials: C
authors.lastname: Gaeta
authors.forename: Myroslav O
authors.initials: MO
authors.lastname: Vysotsky
authors.forename: Anca
authors.initials: A
authors.lastname: Bogdan
authors.forename: Volker
authors.initials: V
authors.lastname: Böhmer
mesh_terms: D047250:Calixarenes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D010636:Phenols / Q000138:chemical synthesis / Q000737:chemistry*; D043862:Rotaxanes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D010636:Phenols; D043862:Rotaxanes; C121325:calix(4)arene; D047250:Calixarenes