Rational Design and Synthesis of Hybrid Porous Polymers Derived from Polyhedral Oligomeric Silsesquioxanes via Heck Coupling Reactions

Abstract

Heck coupling reactions are introduced as an efficient method to prepare porous polymers. Novel inorganic-organic hybrid porous polymers (HPPs) were constructed via Heck coupling reactions from cubic functional polyhedral oligomeric silsesquioxanes (POSS), iodinated octaphenylsilsesquioxanes (OPS) and octavinylsilsesquioxanes (OVS) using Pd(OAc)2 /PPh3 as the catalyst. Here, two iodinated OPS were used, IOPS and p-I8 OPS. IOPS was a mixture with 90% octasubstituted OPS (I8 ) and some nonasubstituted OPS (I9 ), while p-I8 OPS was a nearly pure compound with ≥99% I8 and ≥93% para-substitution. IOPS and p-I8 OPS reacted with OVS to produce the porous materials HPP-1 and HPP-2, which exhibited comparable specific surface areas with SBET of 418 ± 20 m(2) g(-1) and 382 ± 20 m(2) g(-1) , respectively, with total pore volumes of 0.28 ± 0.01 cm(3) g(-1) and 0.23 ± 0.01 cm(3) g(-1) , respectively. HPP-1 showed a broader pore size distribution and possessed a more significant contribution from the mesopores, when compared with HPP-2, thereby indicating that IOPS may induce more disorder because of the geometrical asymmetry. HPP-1 and HPP-2 possessed moderate carbon dioxide uptakes of 134 and 124 cm(3) g(-1) at 1 bar at 195 K, making them promising candidates for CO2 capture and storage. The synthesized porous polymers may be easily post-functionalized using the retained ethenylene groups.

Tailor‐Made Hybrid Organic–Inorganic Porous Materials Based on Polyhedral Oligomeric Silsesquioxanes (POSS) by the Step‐Growth Mechanism of Thiol‐Ene “Click” Chemistry

“…These are organic-inScheme 1. a) vinylPOSS (RSiO3 =2 ) n shown for n = 8, 10, 12; b) variety of thiol compounds explored in this study; the nomenclature attributed to the linker is identical to the respective polymer; and c) hybrid polymer 1 prepared with vinylPOSS and linker 1. organic hybrid, cage-like nanostructures (e.g., Scheme 1 a) that, in their chemical diversity, have already been used as building blocks for the generation of porous materials through thermolysis [5] and hydrosylation, [6] as well as other coupling reactions. [7] The preparation of monolithic porous materials involving POSS has often been addressed with amines, [8] and through uncontrolled, free-radical copolymerization with other monomers. [9] Recently, porous monolithic adsorbents prepared by simple free-radical polymerization of vinylPOSS have been reported.…”

An Efficient Approach to Octabromophenylethyl‐Functionalized Cage Silsesquioxane and Its Use in Constructing Hybrid Porous Materials

“…[10] Second, an efficient polymerization process should be selected to link those monomers together over a broad scale range. Many hybrid porous materials based on specific monomers have been reported, and they have been obtained by various polymerization reactions, such as the Ullmann cross-coupling reaction, [11] Sonogashira-Hagihara coupling reaction, [12] Suzuki coupling reaction, [13] Heck reaction, [14] Friedel-Crafts reaction, [15] and others. [16] These two key issues can provide a straightforward strategy to obtain porous polymers.…”

High Surface Area, Thermally Stable, Hydrophobic, Microporous, Rigid Gels Generated at Ambient from MeSi(OEt)3/(EtO)3SiCH2CH2Si(OEt)3 Mixtures by F−‐Catalyzed Hydrolysis

“…Many highs urface area organic materialss uch as hyper-cross-linked styrene-divinylbenzene copolymers are made by the porogen methodw ith surface areas approaching 2000 m 2 g À1 .S ilsesquioxaneb ased materials fit into the second synthetic methodology,w hereby porosity introduction employs the monomer geometry coupled with controlled polymerization. [13][14][15][16][17][18][19][20][21] Most high surfacea rea materials containing silicon are made via sol-gelp rocessing of tri-and tetraalkoxysilanes. [22][23][24][25] Solgel processing employs acid-or base-catalyzed hydrolysis and condensation to form highly cross-linkedx ero-or aerogels depending on the drying method.…”

“…Gel materials offer SSA'so fu pt o1 300 m 2 g À1 some of the highest known systemsb ased on SQs. [15][16][17][18][19][20][21][22][23][24] Gel materials also offer solvent uptake up to 600 %b ymass. Vinyl groups can be incorporated into the systemso ffering post polymerization functionalization points and further crosslink density,e xtending the useful possibilities for these materials.…”