title: Synthesis of OMS Materials and Investigation of Their Acceptor-Donor Characteristics.
abstract: Three ordered mesoporous siliceous (OMS) materials known as MCM41s-unmodified MCM-41C16 ("C16"), and two MCM41s with different surface functionalities: MCM-41C16-SH ("C16-SH") and MCM-41C16-NH2("C16-NH2")-were synthesized and studied by inverse gas chromatography in order to determine their acceptor-donor properties. The specific retention volumes of nonpolar and polar probes that were chromatographed on these ordered mesoporous silica adsorbents were evaluated under infinite dilution conditions. Two methods were employed to calculate the standard free energy of adsorption, ΔGads, of each chromatographed probe on the basis its specific retention volume. These ΔGadsvalues were then employed to estimate the van der Waals contribution and the specific contribution of the free surface energy for each MCM41. DN values (donor numbers, based on the Gutmann scale) and AN* values (acceptor numbers, based on the Riddle-Fowkes scale) were employed to determine the values of parameters that characterize the ability of the MCM41s to act as electron acceptors (parameter:KA) and donors (parameter:KD). Considering the different compositions of the probes, each of which has different acceptor-donor properties, a new chromatographic test to supplement the Grob test is suggested.
authors.affiliation: Institute of Chemistry, Military University of Technology, Warsaw, Poland.
authors.forename: H
authors.initials: H
authors.lastname: Grajek
authors.forename: J
authors.initials: J
authors.lastname: Paciura-Zadrożna
authors.forename: J
authors.initials: J
authors.lastname: Choma
authors.forename: E
authors.initials: E
authors.lastname: Michalski
authors.forename: Z
authors.initials: Z
authors.lastname: Witkiewicz
keywords: Acceptor–donor properties; Inverse gas chromatography; Mesoporous ordered siliceous adsorbents