title: Self-assembly dynamics of modular homoditopic bis-calix[5]arenes and long-chain alpha,omega-alkanediyldiammonium components.
abstract: Homoditopic building blocks 1, featuring two pi-rich cone-like calix[5]arene moieties connected at their narrow rims by a rigid o-, m-, or p-xylyl spacer in a centrosymmetric divergent arrangement, show a remarkable tendency to spontaneously and reversibly self-assemble with the complementary homoditopic alpha,omega-alkanediyldiammonium dipicrate guest salts C8-C12 x 2Pic through iterative intermolecular inclusion events, forming supramolecular assemblies whose composition and dynamics strongly depend upon the length of the connector, the geometry of the spacer, as well as the concentration and/or molar ratios between the two components. (1)H NMR spectroscopy and ESI-MS studies of 1/C(n) x 2Pic modular homoditopic pairs support the formation of discrete (bis)-endo-cavity assemblies with the shorter C8 and C9 connectors, and/or (poly)capsular assemblies with the longer C10-C12 components under appropriate concentrations and molar ratios (50 mM equimolar solutions). (1)H NMR titration experiments and diffusion NMR studies provide clear evidence for the self-assembly dynamics of the complementary pairs here investigated.
authors.affiliation: Dipartimento di Chimica Organica e Biologica, Università di Messina, Salita Sperone 31, 98166 Messina, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gattuso
authors.forename: Anna
authors.initials: A
authors.lastname: Notti
authors.forename: Andrea
authors.initials: A
authors.lastname: Pappalardo
authors.forename: Melchiorre F
authors.initials: MF
authors.lastname: Parisi
authors.forename: Ilenia
authors.initials: I
authors.lastname: Pisagatti
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Pappalardo
authors.forename: Domenico
authors.initials: D
authors.lastname: Garozzo
authors.forename: Angela
authors.initials: A
authors.lastname: Messina
authors.forename: Yoram
authors.initials: Y
authors.lastname: Cohen
authors.forename: Sarit
authors.initials: S
authors.lastname: Slovak
mesh_terms: D047250:Calixarenes / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008968:Molecular Conformation; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013816:Thermodynamics
chemical_list: D000644:Quaternary Ammonium Compounds; D047250:Calixarenes