title: Diol-linked microporous networks of cubic siloxane cages.
abstract: A new class of inorganic-organic hybrid porous materials has been synthesized by a reaction between octa(hydridosilsesquioxane) (H(8)Si(8)O(12)), which has a double-four-ring (D4R) structure, and various diols, such as 1,3-propanediol (PD), 1,4-cyclohexanediol (CHD), and 1,3-adamantanediol (AD). Solid-state (29) Si magic-angle-spinning NMR spectroscopic analysis confirmed that most of the corner Si-H groups reacted with diols to form Si-O-C bonds with retention of the D4R cage. Nitrogen adsorption-desorption studies showed that the products are microporous solids with high BET surface areas (up to ≈580 m(2) g(-1) for CHD- and AD-linked products). If n-alkanediols are used as linkers, the surface area becomes smaller as the number of carbon atoms is increased. The thermal and hydrolytic stability of the products strongly depend on the type of diol linkers. The highest stabilities are found for the AD-linked products, which are thermally stable up to around 400 °C and remain intact even after being soaked in water for 1 day. In contrast, the PD-linked product is easily hydrolyzed in water to give microporous silica. These results offer a new route toward a series of silica-based porous materials with unique structures and properties.
authors.affiliation: Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Wada
authors.forename: Kenta
authors.initials: K
authors.lastname: Iyoki
authors.forename: Ayae
authors.initials: A
authors.lastname: Sugawara-Narutaki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okubo
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shimojima
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D003511:Cyclohexanols / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011409:Propylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry*; D017655:Silicon Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D012833:Siloxanes / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: C550825:1,3-adamantanediol; D003511:Cyclohexanols; D011409:Propylene Glycols; D017655:Silicon Compounds; D012833:Siloxanes; C064620:1,4-cyclohexanediol; C041787:1,3-propanediol; D000218:Adamantane