title: "Thiol-ene" photoclick chemistry as a rapid and localizable functionalization pathway for silica capillary monolithic columns.
abstract: Herein, we report the "ene-thiol" photografting of 1-octadecanethiol onto vinyl pre-functionalized silica monolith to prepare clicked reversed-phase silica monolithic columns with high permeability and performances. The experimental conditions (concentration of thiol in solution, irradiation duration) are optimized with respect to highest retention and methylene selectivity, i.e. to the highest surface coverage of the monolith. It is demonstrated that an irradiation duration of 5min is enough with a 0.8M concentration of 1-octadecanethiol in solution or that it may be replaced by successive irradiations at a lower ODT concentration (0.19M) with renewing of the solution between the illuminations. Retention factors as high as those obtained with standard silanization are reached while keeping the intrinsic monolith permeability and efficiency (160,000plates/m in nano-LC at 0.7mm/s). The absence of polymerization, in the "ene-thiol" version, is demonstrated. Indeed, the steric selectivity of our clicked-material is characteristic of monolayer-like functionalized silica and significantly lower than the steric selectivity measured on polymeric-like functionalized silica.
authors.affiliation: Université de Lyon, Université Claude Bernard Lyon I, Institut des Sciences Analytiques, UMR CNRS 5280, 5, rue de la DOUA, 69100 Villeurbanne, France.
authors.forename: A
authors.initials: A
authors.lastname: Laaniste
authors.affiliation: Université de Lyon, Université Claude Bernard Lyon I, Institut des Sciences Analytiques, UMR CNRS 5280, 5, rue de la DOUA, 69100 Villeurbanne, France. Electronic address: audreymars@hotmail.fr.
authors.forename: A
authors.initials: A
authors.lastname: Marechal
authors.affiliation: Université de Lyon, Université Claude Bernard Lyon I, Institut des Sciences Analytiques, UMR CNRS 5280, 5, rue de la DOUA, 69100 Villeurbanne, France.
authors.forename: R
authors.initials: R
authors.lastname: El-Debs
authors.affiliation: Université de Lyon, Université Claude Bernard Lyon I, Institut des Sciences Analytiques, UMR CNRS 5280, 5, rue de la DOUA, 69100 Villeurbanne, France.
authors.forename: J
authors.initials: J
authors.lastname: Randon
authors.affiliation: Université de Lyon, Université Claude Bernard Lyon I, Institut des Sciences Analytiques, UMR CNRS 5280, 5, rue de la DOUA, 69100 Villeurbanne, France.
authors.forename: V
authors.initials: V
authors.lastname: Dugas
authors.affiliation: Université de Lyon, Université Claude Bernard Lyon I, Institut des Sciences Analytiques, UMR CNRS 5280, 5, rue de la DOUA, 69100 Villeurbanne, France.
authors.forename: C
authors.initials: C
authors.lastname: Demesmay
mesh_terms: D057930:Click Chemistry / Q000295:instrumentation* / Q000379:methods; D058105:Polymerization; D012822:Silicon Dioxide / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D013438:Sulfhydryl Compounds; C055360:n-octadecyl mercaptan; D012822:Silicon Dioxide
keywords: Nano-LC; Photoclick thiol-ene reaction; Photografting; Silica monolithic columns; Surface functionalization