title: Self-assembly of an alkylated guanosine derivative into ordered supramolecular nanoribbons in solution and on solid surfaces.
abstract: We report on the synthesis and self-assembly of a guanosine derivative bearing an alkyloxy side group under different environmental conditions. This derivative was found to spontaneously form ordered supramolecular nanoribbons in which the individual nucleobases are interacting through H-bonds. In toluene and chloroform solutions the formation of gel-like liquid-crystalline phases was observed. Sub-molecularly resolved scanning tunneling microscopic imaging of monolayers physisorbed at the graphite-solution interface revealed highly ordered two-dimensional networks. The recorded intramolecular contrast can be ascribed to the electronic properties of the different moieties composing the molecule, as proven by quantum-chemical calculations. This self-assembly behavior is in excellent agreement with that of 5'-O-acylated guanosines, which are also characterized by a self-assembled motif of guanosines that resembles parallel ribbons. Therefore, for guanosine derivatives (without sterically demanding groups on the guanine base) the formation of supramolecular nanoribbons in solution, in the solid state, and on flat surfaces is universal. This result is truly important in view of the electronic properties of these supramolecular anisotropic architectures and thus for potential applications in the fields of nano- and opto-electronics.
authors.affiliation: Alma Mater Studiorum-Università di Bologna, Dipartimento di Chimica Organica A. Mangini, Via San Giacomo 11, 40126 Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Lena
authors.forename: Giorgia
authors.initials: G
authors.lastname: Brancolini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gottarelli
authors.forename: Paolo
authors.initials: P
authors.lastname: Mariani
authors.forename: Stefano
authors.initials: S
authors.lastname: Masiero
authors.forename: Alessandro
authors.initials: A
authors.lastname: Venturini
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Palermo
authors.forename: Omar
authors.initials: O
authors.lastname: Pandoli
authors.forename: Silvia
authors.initials: S
authors.lastname: Pieraccini
authors.forename: Paolo
authors.initials: P
authors.lastname: Samorì
authors.forename: Gian Piero
authors.initials: GP
authors.lastname: Spada
mesh_terms: D002725:Chloroform / Q000737:chemistry; D018360:Crystallography, X-Ray; D006151:Guanosine / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry*; D006860:Hydrogen Bonding; D050866:Liquid Crystals; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D014050:Toluene / Q000737:chemistry
chemical_list: D012996:Solutions; D006151:Guanosine; D014050:Toluene; D002725:Chloroform