Chain-growth copolymerization of functionalized ethynylarenes with 1,4-diethynylbenzene and 4,4 0 - diethynylbiphenyl into conjugated porous networks Sabina Stahlová a , Eva Slováková a , Petra Van ˇ kátová a , Arnošt Zukal b , Martin Kubu ˚ b , Jir ˇí Brus c , Dmitrij Bondarev d , Robert Mouc ˇka e , Jan Sedlác ˇek a,⇑ a Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, CZ-128 43 Prague 2, Czech Republic b J. Heyrovsky ´ Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Prague 8, Czech Republic c Institute of Macromolecular Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Heyrovsky ´ Sq. 2, 16206 Prague 6, Czech Republic d Department of Polymer Engineering, Faculty of Technology, Tomas Bata University in Zlín, Vavrec ˇkova 5669, 76001 Zlín, Czech Republic e Centre of Polymer Systems, University Institute, Tomas Bata University in Zlín, Nad Ovc ˇírnou 3685, 76001 Zlín, Czech Republic article info Article history: Received 2 February 2015 Received in revised form 21 March 2015 Accepted 29 March 2015 Available online 9 April 2015 Keywords: Polyacetylenes Diethynylbenzene Diethynylbiphenyl Conjugated networks Microporous polymers Rh-catalyst abstract We report the synthesis of conjugated highly cross-linked polyacetylene-type networks with a high content of functional groups (–CH 2 OH, –NO 2 , –Ph 2 N, content up to 3.9 mmol/g) via a chain-growth copolymerization of either 1,4-diethynylbenzene or 4,4 0 - diethynylbiphenyl with functionalized mono- and diethynylbenzenes. The backbone of the networks consists of substituted polyene main chains that are cross-linked by arylene links. The optimized combinations of comonomers in the feed provide functionalized net- works with a Brunauer–Emmett–Teller specific surface area up to 667 m 2 /g and enhanced affinity for CO 2 adsorption (compared to the non-functionalized hydrocarbon networks of the same type). The dependence of the specific surface area of the networks on the size and architecture of the comonomers used for the synthesis is discussed in the paper. The reported networks can be classified into the group of conjugated microporous polymers (CMPs). Contrary to the CMPs synthesized by step-growth couplings, significantly lower average comonomer functionality in the feed (f = 1.5–2.0) is sufficient for the high specific surface area to be achieved in the reported polyacetylene-type CMPs. Ó 2015 Elsevier Ltd. All rights reserved. 1. Introduction Microporous Organic Polymers (MOPs), i.e. polymers with permanent micro or micro/mesopores, have become a new class of porous materials over the last decade [1– 5]. The potential applications of MOPs range from (i) gas separation and reversible storage [6–8], (ii) adsorption of chemicals [9,10], (iii) catalysis [11,12], (iv) energy trans- formation and storage [13,14] to (v) optoactive materials and sensors [15,16]. Except for polymers with intrinsic microporosity [17], the microporosity of MOPs results from the rigidity of the polymer segments combined with exten- sive cross-linking and/or hyperbranching [1–5]. Various classifications of MOPs have been applied in the literature [1–5]. If we adopt the source-based classification we can delimit an important subclass of MOPs derived from multifunctional ethynylarenes (MEAs), i.e. monomers con- taining usually from 2 to 4 terminal ethynyl groups attached to the arene core of the molecule. Polycyclotrimerization of MEAs with either Co 2 (CO) 8 or TaCl 5 catalysts leads to hyperbranched, partially cross- http://dx.doi.org/10.1016/j.eurpolymj.2015.03.070 0014-3057/Ó 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +420 221951308. E-mail address: jan.sedlacek@natur.cuni.cz (J. Sedlác ˇek). European Polymer Journal 67 (2015) 252–263 Contents lists available at ScienceDirect European Polymer Journal journal homepage: www.elsevier.com/locate/europolj