Copper‐Free Sonogashira Coupling for High‐Surface‐Area Conjugated Microporous Poly(aryleneethynylene) Networks

Abstract

A modified one-pot Sonogashira cross-coupling reaction based on a copper-free methodology has been applied for the synthesis of conjugated microporous poly(aryleneethynylene) networks (CMPs) from readily available iodoarylenes and 1,3,5-triethynylbenzene. The polymerization reactions were carried out by using equimolar amounts of halogen and terminal alkyne moieties with extremely small loadings of palladium catalyst as low as 0.65 mol %. For the first time, CMPs with rigorously controlled structures were obtained without any indications of side reactions, as proven by FTIR and solid-state NMR spectroscopy, while showing Brunauer-Emmett-Teller (BET) surface areas higher than any poly(aryleneethynylene) network reported before, reaching up to 2552 m(2) g(-1) .

Trends and challenges for microporous polymers

“…Their eligibility for H 2 sorption has been shown experimentally as well as computationally. 5,9,175 Selective incorporation of heteroatoms can provide disruptions in the otherwise homogeneous electron density and have beneficial effects on gas sorption, depending on the nature of the adsorbate. Donor moieties with lone electron pairs such as phosphines or amines provide nucleophilic sites capable of strong interactions with electron-deficient moieties, e.g.…”

“…Synthetic protocols which can be used for the generation of microporous polymers are highly diverse and range from metalcatalyzed or -mediated (Sonogashira, 4,5 Suzuki, 6 Yamamoto, 7 Buchwald-Hartwig, 8 Eglinton, 9 Heck 10 ) to click-type reactions, 11 acid or base-catalyzed polycondensation reactions (formation of polyamides, 12 -imides, [13][14][15] -benzimidazoles, 16,17 -dioxanes, 18 -boroxines and boronate esters, 19 -imines 20 -aminals, 22 azo-bridged compounds [23][24][25] and many others [26][27][28][29] The great variety of synthesis conditions not only allows the usage of differentially functionalized monomers, but much more importantly to find appropriate reaction conditions tolerating any given functional group which is planned to be introduced into the network, i.e. synthesis can be carried out with high chemical orthogonality.…”

Synthesis and Characterization of Functional Triphenylphosphine‐Containing Microporous Organic Polymers for Gas Storage and Separation

“…The CO 2 uptake of 2.61 mmol g −1 for TBPPO‐TEPA is higher than that of many reported triphenylphosphine‐containing nonionic microporous polymer networks, and comparable to the hypercrosslinked porous polymers embedded by phosphonium salt (9.6–12.5 wt%) at the same conditions . Considering the moderate BET surface areas, these polymer networks still demonstrate higher CO 2 uptake ability under the same conditions compared to other alkyne‐bridged conjugated microporous polymers (CMPs) with similar BET surface areas . To determine the binding affinity of the polymers and CO 2 molecules, the isosteric heats of adsorption ( Q st ) for CO 2 were calculated using Clausius–Clapeyron equation from CO 2 adsorption data collected at 273 and 298 K. As shown in Figure , the Q st values of the polymer networks were found to be in the range from 26.1 to 28.9 kJ mol −1 at the near zero‐coverage, which are suitable for postcombustion CO 2 capture because the desorption of CO 2 will be facilitated without an obvious energy penalty.…”

Optical Properties and Sequence Information of Tin‐Centered Conjugated Microporous Polymers

“…Table 1l istst he different reaction conditions and catalyst systems employed.S ynthesis was either based on the procedure for CMPs by Thomas et al (Table 1, CMP 6a) [2] or on ap rotocol developed by our group for the synthesis of PPEs (Table 1, CMP 6h). Table 1l istst he different reaction conditions and catalyst systems employed.S ynthesis was either based on the procedure for CMPs by Thomas et al (Table 1, CMP 6a) [2] or on ap rotocol developed by our group for the synthesis of PPEs (Table 1, CMP 6h).…”

“…[2] Nevertheless, important questions remain, including the characterization and rationalizationo fo pticalp roperties of these partially conjugated materials as ad irect consequence of the network-forming organic connectors. [2] Nevertheless, important questions remain, including the characterization and rationalizationo fo pticalp roperties of these partially conjugated materials as ad irect consequence of the network-forming organic connectors.…”