Hierarchical self-assembly on silicon.
A set of modular components was designed, synthesized, and combined to yield an innovative, robust, and reliable methodology for the self-assembly of large supramolecular structures on silicon wafers. Specific host-guest and H-bonding motifs were embedded in a single molecule by exploiting the remarkable complexing properties of tetraphosphonate cavitands toward methylammonium and methylpyridinium salts and the outstanding homo- and hetero-dimerization capability of the ureidopyrimidone moiety. An assembly/disassembly sequence in solution was devised to assess the orthogonality and reversibility of H-bonding and host-guest interactions. The entire process was fully tested and characterized in solution and then successfully transferred to the solid state. The selected binding motifs resulted to be fully compatible in the assembly mode and individually addressable in the disassembly mode. The complete orthogonality of the two interactions allows the molecular level control of each step of the solid-state assembly and the predictable response to precise external stimuli. Complementary surface analysis techniques, such as atomic force microscopy (AFM), ellipsometry, and fluorescence, provided the univocal characterization of the realized structures in the solid state.
Tancini
Francesca
F
Dipartimento di Chimica Organica e Industriale, Università di Parma, and INSTM UdR Parma, 43124 Parma, Italy.
Genovese
Damiano
D
Montalti
Marco
M
Cristofolini
Luigi
L
Nasi
Lucia
L
Prodi
Luca
L
Dalcanale
Enrico
E
D019281:Dimerization; D006860:Hydrogen Bonding; D008968:Molecular Conformation; D009943:Organophosphorus Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D017646:Organosilicon Compounds / Q000737:chemistry*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013237:Stereoisomerism; D013499:Surface Properties
D009943:Organophosphorus Compounds; D017646:Organosilicon Compounds; D012825:Silicon