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Well-ordered cubic (Pm3 j n symmetry) benzene-bridged periodic mesoporous organosilicas (PMOs) functionalized with variable contents of thiol groups were successfully synthesized via a one-step co-condensation of 1,4-bis(triethoxysilyl)benzene (BTEB) and 3-mercaptopropyltrimethoxysilane (MPTMS) in a highly acidic medium with use of cetyltrimethylammonium bromide (CTMABr) as the structure-directing agent. The materials thus obtained exhibited ordered and uniformed mesopores up to 25 mol % of MPTMS in the initial mixture. Direct evidence of the simultaneous presence of chemically attached thiol and benzene moieties was provided by solid-state 29 Si and 13 C NMR spectroscopy. The present cubic PMOs can be synthesized with a wide temperature window from 0 to 100°C without any undesirable phase transformation. On the contrary, this is not possible when BTEB was replaced by tetraethoxysilane (TEOS) as the silicon source for the conventional synthesis of SBA-1 with Pm3 j n symmetry. It suggests that the benzene-linking spacer of BTEB has a beneficial effect on the enlargement of effective head group of the surfactant against the temperature changes and thus prevents phase transformation to a hexagonal mesophase. These thiol-functionalized benzene-silica materials exhibited high adsorption affinity toward metal ions such as Hg 2+ and Ag + , but not for Cd 2+ , Co 2+ , and Pb 2+ . Of particular interest is that the 13 C NMR chemical shift of the carbon atom adjacent to the -SH group is sensitive to the Hg 2+ and Ag + ion bindings, shifting from 27 ppm to 37 and 34 ppm, respectively. Such a significant NMR shift provides clear evidence that there are strong interactions between the thiol groups and the Hg 2+ and Ag + ions.

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Ordered periodic mesoporous organosilicas containing different fractions of benzene groups in the silica framework, based on the cubic SBA-1 mesostructure (Pm3 j n mesophase), were synthesized with the directsynthesis route via co-condensation of tetraethoxysilane (TEOS) and 1,4-bis(triethoxysilyl)benzene (BTEB) under acidic conditions using cetyltriethylammonium bromide as a structure-directing agent. A significantly large amount of TEOS, up to 70 mol % based on silica, can be incorporated into the silica wall without degrading the structural integrity of the materials. By optimization of the synthesis compositions, the resulting materials exhibited much higher surface areas (up to 1210 m 2 /g) and larger pore volumes (up to 0.64 cm 3 /g) as compared to the previous analogue, which only exhibited a surface area of 381 m 2 /g and a pore volume of 0.11 cm 3 /g. Two-dimensional (2D) 29 Si{ 1 H} heteronuclear correlation (HETCOR) NMR spectra, acquired as a function of contact time, provided direct spectroscopic evidence that a single mesophase with various Q (from TEOS) and T silicon species (from BTEB) located randomly within the pore walls via co-condensation of BTEB and TEOS at a molecular level. Such information is often not achievable by other characterization techniques. The 1 H-29 Si distance information between phenylene protons and nearby T 3 silicon atoms obtained from density functional theory calculations is also in good agreement with the observations of 2D 29 Si{ 1 H} HETCOR NMR experiments.