title: Probing Molecular Recognition at the Solid-Gas Interface by Sum-Frequency Vibrational Spectroscopy.
abstract: Molecular recognition is among the most important chemical events in living systems and has been emulated in supramolecular chemistry, driven by chemical and biochemical sensing potential. Identifying host-guest association in situ at the interface, between the substrate-bound receptors and the analyte-containing media, is essential to predict complexation performances in term of the receptor conformation, orientation and organization. Herein, we report the first sum-frequency vibrational spectroscopy study of molecular recognition at the solid-gas interface. The binding capability of tetraquinoxaline cavitands toward volatile aromatic and aliphatic compounds, namely benzonitrile and acetonitrile, is investigated as test system. We prove the selective complexation of the receptors, organized in a solid-supported hybrid bilayer, toward aromatic compounds. Quantitative analysis allows to correlate the average orientations of the guest molecules and the host binding pockets, establishing "on-axis" complexation of benzonitrile within the cavitand cavity. The study is readily applicable to other receptors, molecular architectures, interfaces and analytes.
authors.affiliation: Department of Physics, University of Calabria , Ponte P. Bucci 31C, 87036 Rende, Cosenza, Italy.|CNR-Nanotec, LiCryL and Centre of Excellence CEMIF.CAL , Ponte P. Bucci 33B, 87036 Rende, Cosenza, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Aprile
authors.affiliation: CNR-Nanotec, LiCryL and Centre of Excellence CEMIF.CAL , Ponte P. Bucci 33B, 87036 Rende, Cosenza, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Ciuchi
authors.affiliation: Department of Chemistry, University of Parma, and INSTM , UdR Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Pinalli
authors.affiliation: Department of Chemistry, University of Parma, and INSTM , UdR Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Dalcanale
authors.affiliation: Department of Physics, University of Calabria , Ponte P. Bucci 31C, 87036 Rende, Cosenza, Italy.|CNR-Nanotec, LiCryL and Centre of Excellence CEMIF.CAL , Ponte P. Bucci 33B, 87036 Rende, Cosenza, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Pagliusi