Rigid wiry nets: Conjugated microporous polymer networks are formed by Sonogashira–Hagihara coupling. Although these materials are amorphous, the micropore size and surface area can be controlled by varying the length of the phenyleneethynylene struts (see picture; the network is shown in blue, and one 1,3,5‐substituted benzene node and three connected struts are highlighted with C gray and H white).

Photocatalytic hydrogen production from water offers an abundant, clean fuel source, but it is challenging to produce photocatalysts that use the solar spectrum effectively. Many hydrogen-evolving photocatalysts are active in the ultraviolet range, but ultraviolet light accounts for only 3% of the energy available in the solar spectrum at ground level. Solid-state crystalline photocatalysts have light absorption profiles that are a discrete function of their crystalline phase and that are not always tunable. Here, we prepare a series of amorphous, microporous organic polymers with exquisite synthetic control over the optical gap in the range 1.94-2.95 eV. Specific monomer compositions give polymers that are robust and effective photocatalysts for the evolution of hydrogen from water in the presence of a sacrificial electron donor, without the apparent need for an added metal cocatalyst. Remarkably, unlike other organic systems, the best performing polymer is only photoactive under visible rather than ultraviolet irradiation.

A series of rigid microporous poly(aryleneethynylene) (PAE) networks was synthesized by Sonogashira-Hagihara coupling chemistry. PAEs with apparent Brunauer-Emmet-Teller surface areas of more than 1000 m(2)/g were produced. The materials were found to have very good chemical and thermal stability and retention of microporosity under a variety of conditions. It was shown that physical properties such as micropore size, surface area, and hydrogen uptake could be controlled in a "quantized" fashion by varying the monomer strut length, as for metal-organic and covalent organic frameworks, even though the networks were amorphous in nature. For the first time, it was demonstrated that these properties can also be fine-tuned in a continuous manner via statistical copolymerization of monomer struts with differing lengths. This provides an unprecedented degree of direct synthetic control over micropore properties in an organic network.

High surface area porous poly(phenylene butadiynylene) networks were obtained (BET surface area up to 842 m(2) g(-1)) by the palladium-catalyzed homocoupling of 1,3,5-triethynylbenzene and 1,4-diethynylbenzene.

We report here the synthesis of conjugated microporous polymers (CMPs) based on pyrene building units. The networks are both microporous and highly luminescent. The emission colour and resulting band gap can be fine tuned by introducing different comonomers and by varying the monomer distribution (statistical versus alternating). These materials might find applications in organic electronics, photocatalysis, optoelectronics, or in sensing technologies.

Microporous materials have potential applications in areas including molecular separation, gas sorption and catalysis. [1] Materials such as metal-organic frameworks (MOFs), [2] covalent organic frameworks (COFs), [3] microporous organic polymers, [4] and porous organic molecular solids [5] all contain organic functionalities which, in principle, can allow significant synthetic diversification. A particular advantage of microporous organic polymers [4] is the potential to introduce a range of useful chemical functionalities into the pores. [6] This stems from the chemical and thermal stability of these networks which facilitates a variety of chemical transformations.Conjugated microporous polymers (CMPs) [4a] can exhibit extended p-conjugation and have been the subject of much recent interest. A variety of CMPs (and closely related structures) have been developed. [4a, 7] The incorporation of metal sites into CMPs could open up second-generation porous materials with useful combined chemical and physical properties such as catalytic activity, electrical conductivity, or light-absorption/emission.[8] For example, metalated CMP materials might be of interest in heterogeneous catalysis or photocatalysis, where high surface areas would be beneficial. There are, however, few demonstrations of the functionalization of CMP networks with metals at the molecular level. The incorporation of metal nanoparticles into microporous networks has been demonstrated.[4e, 7e, 9a] Also, a lithiated CMP showing very high H 2 sorption was described recently but the precise nature of the metal incorporation at the molecular level was not clear.[9b] Another recent report details a porphyrin-derived microporous organic polymer which shows high catalytic activity for the oxidation of thiols. [10] Beyond this, there are no reports on the purposeful synthesis of metal-functionalized CMPs. Here, we report two versatile strategies for preparing metal-organic CMPs (MO-CMPs). Unlike MOFs, [2] the resulting metal-containing conjugated polymers are amorphous. Another significant difference is that the metal sites need not be nodes in the network but can also be attached pendant to the polymer chains, thus allowing the introduction of vacant metal sites and a range of chemically active functionalities. The introduction of pendant metal sites rather than metal nodes also allows the preparation of materials with unbroken extended conjugation.The MO-CMP networks were prepared either by posttreating a bipyridine-functionalized CMP precursor with a metal complex or by the direct Sonogashira-Hagihara crosscoupling of 1,3,5-triethylbenzene or 1,4-dibromobenzene and a halogenated metal-organic co-monomer. These two strategies can be defined as post-synthetic metalation and direct metal incorporation by copolymerization. The representative structures of the target MO-CMP networks are shown in Scheme 1. These polymers combine conjugation along the main chain with functional units such as bipyridine or phenylpyridine in the backbone in order to provide site...

Microporous poly(tri(4-ethynylphenyl)amine) networks were synthesized by palladium-catalyzed Sonogashira-Hagihara cross-coupling chemistry with apparent Brunauer-Emmet-Teller (BET) specific surface areas in the range 500-1100 m2/g. It was found that very fine synthetic control over physical properties such as BET surface area, Langmuir surface area, micropore surface area, micropore volume, and bulk density could be achieved by varying the average monomer strut length. The micropore structure and micropore surface area were rationalized by atomistic simulations for one network, NCMP-0, based on multiple physical characterization data

Conjugated microporous polymers (CMPs) based on the electron-withdrawing 1,3,5-triazine node (TCMPs) were synthesized by palladium-catalyzed Sonogashira-Hagihara cross-coupling. The porosity in these polymers was found to be comparable to the analogous 1,3,5-connected benzene CMP systems that we reported previously, demonstrating that nodes can be substituted in these amorphous materials in a rational manner, much as for certain crystalline porous metal-organic frameworks. The CO 2 adsorption properties of the TCMPs were measured and compared with the corresponding CMPs, and it was found that the TCMP networks adsorbed more CO 2 than CMP analogues with comparable BET surface areas. Network TNCMP-2 showed the highest surface area (995 m 2 g À1 ) and a CO 2 uptake of 1.45 mmol g À1 at 1 bar at 298 K. The band gap in these triazine-based CMPs could also be engineered through copolymerization with other functional monomers.