title: Immobilization of cryptophane derivatives onto SiO2/Au and Au substrates.
abstract: The synthesis of a cryptophane molecule bearing five methoxy substituents and an alkanethiol chain, 4, as well as its subsequent grafting onto a gold surface, is reported. Immobilization of cryptophane derivatives onto silica (SiO2/Au) surfaces was also performed by reacting a cryptophane molecule bearing one or six acid functions, 5 or 6, respectively, with an amino-terminated self-assembled monolayer (SAM). Polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) was used to characterize the two types of cryptophane monolayers. Surface coverage of cryptophane monolayers was estimated by comparing the PM-IRRAS intensity of cryptophane bands with that calculated from the optical constants of pentamethoxy-cryptophane for a compact monolayer. A very efficient grafting of 4 onto a gold surface was found, with a surface coverage close to 100%. On the other hand, the reaction of mono-acid, 5, or hexa-acid, 6, cryptophanes with amino-terminated SAM was less efficient, since the surface coverage did not exceed 15%. Finally, a good surface coverage (75%) was also obtained by using a cysteamine coupling agent to modify 5 before its grafting onto a gold surface.
authors.affiliation: Institut des Sciences Moléculaires (UMR 5255-CNRS), Université de Bordeaux , 351 Cours de la Libération, 33405 Talence, France.
authors.forename: Elise
authors.initials: E
authors.lastname: Siurdyban
authors.forename: Thierry
authors.initials: T
authors.lastname: Brotin
authors.forename: Karine
authors.initials: K
authors.lastname: Heuzé
authors.forename: Luc
authors.initials: L
authors.lastname: Vellutini
authors.forename: Thierry
authors.initials: T
authors.lastname: Buffeteau