Functionalization on Silica Gel with Allylsilanes. A New Method of Covalent Attachment of Organic Functional Groups on Silica Gel

Abstract

Treatment of an (allyl)organosilane with silica gel in refluxing toluene brought about deallylation forming an Si-O-Si bond with the silicon on the silica gel. This Si-O-Si bond formation provides us with a new reliable method for the functionalization of a silica gel surface.

Versatile Double-Cross-Linking Approach to Transparent, Machinable, Supercompressible, Highly Bendable Aerogel Thermal Superinsulators

“…For PVPMS and PAPMS aerogels, the small peak recognized at around -68 ppm can be attributed to T 3 (RSiO3/2, R may be methyl) species that are probably derived from the reaction between allylsilane or vinylsilane and silanol to form a siloxane bond and T silicon. 35,36 The similar This is the original manuscript before revision.…”

Effective separation of organic dyes using ionic liquids as green mobile phase and polyaniline-modified silica gel nanocomposite-based thin-layer chromatography

“…Separations of mixture of organic dyes were more efficiently achieved on Pani@SG in comparison to SG. It may be understood that on modification of silica gel surface, there is a partial conversion of surface silanol groups to new organo-functional groups imparting considerably different sets of properties to the SG surface than the original (Shimada et al 2003).…”

Facile Synthesis of a Luminescent Material, PAN@{SiO2}n, Having a Simultaneous Binding Capacity of High and Low Oxidation States: HOMO and LUMO, Quantum-mechanical Descriptor of Break-through Capacity

“…[11][12][13][14][15][16][17][18][19][20][21] The composition ({Si A new kind of reaction occurs, whereby the material uniquely binds two different metal centers (Cd(II) and Tl(I)) in their HLOS simultaneously at its respective HOMO and LUMO, residing at two different spatial locations (Scheme 2a). Thereby, it differs from the existing mode of reaction reported until now (Scheme 2b).…”

“…7,13,14 It is obtained by either coating a high molecular mass liquid cation exchanger (HMMLCE) on silanised SG, 9,13 or by the formation of covalent siloxanes (Si-O-Si) (denoted as grafting) 15,16 through a suitable grafting component (viz. 3-aminopropyltrimethoxysilane, 11 3-mercaptopropyltrimethoxy-silane, 17 allyl-, 18 methallyl-, 19 vinylsilane, 20 isocyanosilane 21 hydrosilanes 16 etc.). After that, a selective chelating agent (e.g., 1,5-bis(di-2-pyridylmethylene) thiocarbonohydrazide (DPTH), Xylenol orange (XO), Eriochrome black T (EBT), PAN etc.)…”

“…15,16 However, the cross-linking activity of the bridging component increases the size of FSG, and its surface activity was turned down to a moderate level. 11 Moreover, such a type of siloxane synthesis either required complicated steps under stringent reaction conditions (refluxing, 24 -90 h; starring; very high or low temperature; repetitive filtrations; inert atmosphere; vacuum; costly and hazardous chemicals), 8,11,17,22 or needs very strong Lewis acids (like B(C6F5)3 in the hydrosilylation reaction) 16 or transition/noble metals [18][19][20] as a catalyst. Such extractors having HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) at the same spatial location are able to bind metals either at high or low oxidation states (OS) using their HOMO and LUMO operative on the same metal center.…”