Mesoporous benzene-silica hybrid materials with a different degree of order in the wall structure: an IR comparative study.
Recent joint IR and computational work (Onida et al. J. Phys. Chem B 2005) has allowed a detailed characterization of the isolated silanols at the surface of highly ordered benzene-silica hybrid material. In the present paper, a similar characterization is provided for a less ordered sample. The comparison permits the assignment of IR features to the interaction of silanols either with one another or with benzene rings of the structure. The extent of structural imperfections appears to be limited, for example, no more than pairs of interacting silanols are found, readily healed by thermal treatment. Evidence is also provided that probe molecules with simultaneous H-acceptor and H-donor properties (benzene, methylacetylene) may interact with both the acidic proton in silanols and the electronic cloud in the framework aromatic rings.
Onida
Barbara
B
Dipartimento di Scienza dei Materiali e Ingegneria Chimica, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10138 Torino, Italy.
Camarota
Beatrice
B
Ugliengo
Piero
P
Goto
Yasutomo
Y
Inagaki
Shinji
S
Garrone
Edoardo
E
D001554:Benzene / Q000737:chemistry*; D006860:Hydrogen Bonding; D016062:Porosity; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014732:Vibration
D012822:Silicon Dioxide; D001554:Benzene