Porous organic polymers derived from tetrahedral silicon-centered monomers and a stereocontorted spirobifluorene-based precursor: synthesis, porosity and carbon dioxide sorption

Abstract

Sonogashira-Hagihara coupling reactions of tetrahedral silicon-centered monomers, i.e., tetrakis(4bromophenyl)silane (p-Si) and tetrakis(3-bromophenyl)silane (m-Si), and stereocontorted 2,2 0 ,7,7 0tetraethynyl-9,9 0 -spirobifluorene (TESF) result in two novel porous organic polymers, POP-1 and POP-2.Compared with other porous polymers, these materials show high thermal stability and comparable specific surface areas with Brunauer-Emmer-Teller surface areas of up to 983 m 2 g À1 , and total pore volumes of up to 0.81 cm 3 g À1 (POP-1). The N 2 isotherm analysis reveals that their porosities could be tuned by changing the structure geometry of the silicon-centered monomers. Further porosity comparison with other porous polymers indicates that the introduction of silicon-centered units in the porous networks could increase the porosity and copolymerization, i.e., changing the second monomer, is an efficient strategy to tune the porosity of the final materials. For applications, the resulting materials show moderate carbon dioxide uptakes of up to 1.92 mmol g À1 (8.45 wt%) at 273 K and 1.03 bar, and 1.12 mmol g À1 (4.93 wt%) at 298 K and 1.01 bar (POP-1), and also a comparably high binding ability with CO 2 with an isostreic heat of 26.8 kJ mol À1 (POP-1). Moreover, the materials exhibited moderate selectivity of CO 2 over other gases, including N 2 , O 2 and CH 4 . These results reveal that these materials could be potentially applied as promising candidates for storing and capturing CO 2 . † Electronic supplementary information (ESI) available: CO 2 adsorption and desorption isotherms of POP-1 and POP-2 at 273 K and 298 K, isosteric heat of CO 2 adsorption of POP-1 and POP-2, Toth model tting of CO 2 , N 2 , CH 4 and O 2 adsorption isotherms of POP-1 and POP-2. See Scheme 1 Synthetic routes of porous organic polymers, POP-1 and POP-2. (i): Pd(PPh 3 )/CuI, DMF/i-Pr 2 NH, 90 C, 72 h. The fragments of these porous polymers are shown as examples. 64164 | RSC Adv., 2015, 5, 64163-64169 This journal is

A ferrocene‐containing porous organic polymer linked by tetrahedral silicon‐centered units for gas sorption

“…70 ppm arising from ethynylene (−C ≡ C‐) units confirmed the formation of internal C‐C triple bonds between the ethynyl units and ferrocene units. This position is slightly smaller than the data in our previous report before, which is probably due to the electron‐withdrawing property of ferrocene unit. The resonance from 120 ~ 140 ppm can be assigned to the aromatic carbon atoms from phenylene and ferrocene units.…”

“…The porosity is comparable to other organosilicon porous polymers, for example, lower than the polymer derived from tetrakis(4‐bromophenyl)silane and 2,2′,7,7′‐tetrabromo‐9,9′‐spirobifluorene (S BET : 983 m 2 g −1 ), but higher than those polymers constructed from tetrakis(4‐bromophenyl)silane and pyridine‐based precursors (the highest S BET is 410 m 2 g −1 ) . Moreover, the different porosity among the present polymer and other porous polymers further reveals that co‐polymerization is an efficient strategy to tune the porosity of the resultant polymers.…”

Charged Metalloporphyrin Polymers for Cooperative Synthesis of Cyclic Carbonates from CO2 under Ambient Conditions

“…Relatively high values of CO 2 /N 2 adsorption selectivity (40 for Al‐iPOP‐1 and 42 for Al‐iPOP‐2) were acquired from the isotherms under the linear low pressure at 273 K from Henry's Law constant. Thus, the presence of ionic functional groups within the POPs improves the interaction between CO 2 molecules and the porous framework (Figure S6), which is crucial for the transformation of CO 2 , especially if flue gas is used as a feedstock …”

“…Thus, the presence of ionic functional groups within the POPs improves the interaction between CO 2 molecules and the porousf ramework ( Figure S6), which is crucial for the transformation of CO 2 ,e specially if flue gas is used as af eedstock. [26] Additionally,t hese new POPs exhibited outstanding swelling properties in DMF.T hus, to understand the special behavior of these materials in the CO 2 /epoxide cycloaddition reaction, liquid-swelling measurements were performedi nt he reaction substrates and products,t hat is, propylene epoxide (PO) and propylene carbonate (PC; Figure S7). Clearly, all of the polymers were gelatinous in both weakly polar PO and strongly polar PC after swelling ( Figure 4A).…”

Porous Organic Polymers for CO2 Storage and Conversion Reactions

“…In this context Ma et al. have reported a new class of POPs bearing Si‐atoms by using tetrahedral organosilicon monomers and employing Sonogashira‐Hagihara C−C coupling reaction . These POPs possess high BET surface areas up to 983 m 2 g −1 and considerably good CO 2 uptake capacities.…”