Regulating Charge-Transfer in Conjugated Microporous Polymers for Photocatalytic Hydrogen Evolution

Bandgap engineering in donor–acceptor conjugated microporous polymers (CMPs) is a potential way to increase the solar-energy harvesting towards photochemical water splitting. Here, the design and synthesis of a series of donor–acceptor CMPs [tetraphenylethylene (TPE) and 9-fluorenone (F) as the donor and the acceptor, respectively], F_0.1CMP , F_0.5CMP , and F_2.0CMP , are reported. These CMPs exhibited tunable bandgaps and photocatalytic hydrogen evolution from water. The donor–acceptor CMPs exhibited also intramolecular charge-transfer (ICT) absorption in the visible region (λ_max=480 nm) and their bandgap was finely tuned from 2.8 to 2.1 eV by increasing the 9-fluorenone content. Interestingly, they also showed emissions in the 540–580 nm range assisted by the energy transfer from the other TPE segments (not involved in charge-transfer interactions), as evidenced from fluorescence lifetime decay analysis. By increasing the 9-fluorenone content the emission color of the polymer was also tuned from green to red. Photocatalytic activities of the donor–acceptor CMPs ( F_0.1CMP , F_0.5CMP , and F_2.0CMP ) are greatly enhanced compared to the 9-fluorenone free polymer ( F_0.0CMP ), which is essentially due to improved visible-light absorption and low bandgap of donor–acceptor CMPs. Among all the polymers F_0.5CMP with an optimum bandgap (2.3 eV) showed the highest H₂ evolution under visible-light irradiation. Moreover, all polymers showed excellent dispersibility in organic solvents and easy coated on the solid substrates.     

共轭微孔聚合物的制备与应用

共轭微孔聚合物(CMPs)是一类有机多孔聚合物,与常规共轭聚合物或多孔材料相比,其最大的特点是既有π共轭骨架又具有大量微孔.这类材料在解决能源和环境问题方面显示出巨大的潜力,已在气体吸附、非均相催化、发光材料、化学传感器、电能存储和生物杂化物等领域显示出巨大的应用前景.目前已开发出多种用于CMPs结构单元设计与合成的新...     

CO2‐Triggered Switchable Hydrophilicity of a Heterogeneous Conjugated Polymer Photocatalyst for Enhanced Catalytic Activity in Water

Water compatibility for heterogeneous photocatalysts has been pursued for energy and environmental applications. However, there exists a trade‐off between hydrophilicity and recyclability of the photocatalyst. Herein, we report a conjugated polymer photocatalyst with tertiary amine terminals that reversibly binds CO₂ in water, thereby generating switchable hydrophilicity. The CO₂‐assisted hydrophilicity boosted the photocatalytic efficiency in aqueous medium with minimum dosage. When CO₂ was desorbed, the photocatalyst could be simply regenerated from reaction media, facilitating the repeated use of photocatalyst. Hydrophilicity/hydrophobicity control of the polymer photocatalyst was successfully showcased through a variety of organic photoredox reactions under visible‐light irradiation in water.     

自由基修饰共轭微孔聚合物应用于5-羟甲基糠醛选择性氧化

采用有机单体侧链嫁接2,2,6,6-四甲基哌啶氧自由基（2,2,6,6-tetramethylpiperidineoxyl,TEMPO）的策略将TEMPO嫁接到2,5-二溴苯甲酸侧链,并与四（4-乙炔基苯）甲烷通过Sonogashira偶联反应,构筑TEMPO自由基功能化共轭微孔聚合物CMP-4-TEMPO.利用核磁共振谱（NMR）、扫描电子显微镜（SEM）、粉末X-射线衍射（XRD）红外吸收光谱（FT-IR）和电子顺磁共振谱（EPR）等技术研究了所合成单体及CMP形貌和结构.催化性能测试结果表明CMP-4-TEMPO可将5-羟甲基糠醛（5-HMF）高效、高选择性氧化成高附加值2,5-二甲酰基呋喃（2,5-DFF）.CMP-4-TEMPO催化剂循环利用10次仍保持较高的转化率.提出了CMP-4-TEMPO中形成TEMPO氧正离子是实现5-HMF转化为2,5-DEF的催化氧化机理.CMP-4-TEMPO有望成为各种醇高效、高选择性氧化以及可循环利用的异相催化剂.     

Conformation Control of Conjugated Polymers

In the past few decades, conjugated polymers have aroused extensive interest in organic electronic applications. The electrical performance of conjugated polymers has a close relationship with their backbone conformation. The conformation of the polymer backbone strongly affects the πelectron delocalization along polymer chains, the energy band gap, interchain interactions, and further affects charge transport properties. To realize a rigid coplanar backbone that usually possesses efficient intrachain charge transport properties and enhanced π–π stackings, such conformation control becomes a useful strategy to achieve high-performance (semi)conducting polymers. This minireview summarizes the most important polymer structures through conformation control at the molecular level, and then divides these rigid coplanar conjugated polymers into three categories: 1) noncovalent interactions locked conjugated polymers; 2) double-bond linked conjugated polymers; 3) ladder conjugated polymers. The effect of the conformation control on physical nature, optoelectronic properties, and their device performance is also discussed, as well as the challenges of chemical synthesis and structural characterization.     

4‐(N,N‐Dimethylamino)pyridine‐Embedded Nanoporous Conjugated Polymer as a Highly Active Heterogeneous Organocatalyst

We report herein for the first time the incorporation of a versatile organocatalyst, 4‐(N,N‐dimethylamino)pyridine (DMAP), into the network of a nanoporous conjugated polymer (NCP) by the “bottom‐up” approach. The resulting DMAP‐NCP material possesses highly concentrated and homogeneously distributed DMAP catalytic sites (2.02 mmol g^?1). DMAP‐NCP also exhibits enhanced stability and permanent porosity due to the strong covalent linkage and the rigidity of the “bottom‐up” monomers. As a result, DMAP‐NCP shows excellent catalytic activity in the acylation of alcohols with yields of 92–99 %. The DMAP‐NCP catalyst could be easily recovered from the reaction mixture and reused in at least 14 consecutive cycles without measurable loss of activity. Moreover, the catalytic acylation reaction could be performed under neat and continuous‐flow conditions for at least 536 h of continuous work with the same catalyst activity.     

金属有机骨架材料在催化中的应用

金属有机骨架(MOFs)材料是一种相对新型的多孔材料,由于其结构的多样性、可设计性、可剪裁性以及超高的比表面积,近年来吸引了广泛的研究兴趣,并在很多领域展现了潜在的应用前景.特别是在催化方面的应用更受到了强烈的关注.本文的前两部分主要以催化活性位点的来源进行分类,包括配位不饱和金属中心、功能性有机配体、化学修饰接入功能位点以及嵌入在MOFs孔内的金属配合物或金属纳米颗粒等,总结了近几年来MOFs及其复合材料在多相催化方向取得的一些进展.同时在后面两部分也简要地介绍了MOFs在光催化及以MOFs为模板构筑的多孔纳米材料在催化(特别是电催化)方面的一些应用.最后,对MOFs在催化方面的应用前景做了展望.     

Tunable Surface Area,Porosity, and Function in Conjugated Microporous Polymers

Simple inorganic salts are used to tune N‐containing conjugated microporous polymers (CMPs) synthesized by Buchwald–Hartwig (BH) cross‐coupling reactions. Poly(triphenylamine), PTPA, initially shows a broad distribution of micropores, mesopores, and macropores. However, the addition of inorganic salts affects all porous network properties significantly: the pore size distribution is narrowed to the microporous range only, mimicking COFs and MOFs; the BET surface area is radically improved from 58 m² g^?1 to 1152 m² g^?1; and variations of the anion and cation sizes are used to fine‐tune the surface area of PTPA, with the surface area showing a gradual decrease with an increase in the ionic radius of salts. The effect of the salt on the physical properties of the polymer is attributed to adjusting and optimizing the Hansen solubility parameters (HSPs) of solvents for the growing polymer, and named the Beijing–Xi'an Jiaotong (BXJ) method.     

Ultrastable Conjugated Microporous Polymers Containing Benzobisthiadiazole and Pyrene Building Blocks for Energy Storage Applications

In recent years, conjugated microporous polymers (CMPs) have become important precursors for environmental and energy applications, compared with inorganic electrode materials, due to their ease of preparation, facile charge storage process, π-conjugated structures, relatively high thermal and chemical stability, abundance in nature, and high surface areas. Therefore, in this study, we designed and prepared new benzobisthiadiazole (BBT)-linked CMPs (BBT–CMPs) using a simple Sonogashira couplings reaction by reaction of 4,8-dibromobenzo(1,2-c;4,5-c′)bis(1,2,5)thiadiazole (BBT–Br₂) with ethynyl derivatives of triphenylamine (TPA-T), pyrene (Py-T), and tetraphenylethene (TPE-T), respectively, to afford TPA–BBT–CMP, Py–BBT–CMP, and TPE–BBT–CMP. The chemical structure and properties of BBT–CMPs such as surface areas, pore size, surface morphologies, and thermal stability using different measurements were discussed in detail. Among the studied BBT–CMPs, we revealed that TPE–BBT–CMP displayed high degradation temperature, up to 340 °C, with high char yield and regular, aggregated sphere based on thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), respectively. Furthermore, the Py–BBT–CMP as organic electrode showed an outstanding specific capacitance of 228 F g⁻¹ and superior capacitance stability of 93.2% (over 2000 cycles). Based on theoretical results, an important role of BBT–CMPs, due to their electronic structure, was revealed to be enhancing the charge storage. Furthermore, all three CMP polymers featured a high conjugation system, leading to improved electron conduction and small bandgaps.     

四苯基乙烯基共轭微孔聚合物的制备及其气体吸附

共轭微孔聚合物由于其在气体吸附与分离、非均相催化和光电子等领域的巨大应用前景而广受关注. 本文以四苯基乙烯为基本构筑单元, 通过Sonogashira-Hagihara偶联反应制备了3种共轭微孔聚合物新材料, 研究了结构组成和构建模块对制备聚合物孔性能和气体吸附性能的影响. 氮气吸附测试结果表明, 由1,1,2,2-四炔四苯基乙烯自聚合制备的TPE-CMP1具有较大的比表面积, 为1096 m²·g^-1. 在1.13 bar/273 K条件下, TPE-CMP1的CO₂吸附能力为2.36 mmol·g^-1; 在1.13 bar/77.3 K条件下, TPE-CMP1对H₂的吸附能力为1.35 wt%. 另外, 制备的共轭微孔聚合物展示出较高的CO₂/N₂选择性吸附值. 由于这类多孔聚合物材料具有合成方法简单、优良的物理化学及热稳定性、高的比表面积和CO₂吸附性能, 因此将在气体吸附与分离方面具有潜在的应用前景.     

基于水溶性共轭聚合物的蛋白质检测*

近年来,以共轭聚合物作为生物传感元件,在生物大分子（如核酸、蛋白质）特异性识别、检测方面的研究越来越受到人们的关注。共轭聚合物具有强的光捕获能力,具有倍增光学响应性,可用来放大荧光传感信号,大大提高检测的灵敏度,为生物传感器的发展提供了新的传感模式。基于共轭聚合物的新型生物传感器在医疗诊断、环境检测以及国家安全防御等方面具有广泛的应用前景。本文简要介绍了共轭聚合物的荧光信号放大机制以及在蛋白质、酶、抗原－抗体检测方面的应用。最后对共轭聚合物在蛋白质检测方面的未来发展趋势进行了展望。     

树枝状共轭聚合物研究

本文介绍了树枝状共轭聚合物的最新发展,包括全共轭、部分共轭树枝状聚合物及树枝化共轭聚合物的特点及其在电致发光、电极、传感器以及光探测等领域的功能化应用;详细讨论了包括代数、支化单元、端基、核、金属离子的络合等结构因素以及溶剂和浓度等工艺因素对电荷传输的影响;并进一步提出该领域研究前景及有待于解决的问题.     

树枝状共轭聚合物研究

本文介绍了树枝状共轭聚合物的最新发展,包括全共轭、部分共轭树枝状聚合物及树枝化共轭聚合物的特点及其在电致发光、电极、传感器以及光探测等领域的功能化应用;详细讨论了包括代数、支化单元、端基、核、金属离子的络合等结构因素以及溶剂和浓度等工艺因素对电荷传输的影响;并进一步提出该领域研究前景及有待于解决的问题。     

共轭聚合物离子荧光化学传感器

荧光传感器能够将分子识别的信息转换成荧光信号,荧光法在灵敏度、选择性和实时原位检测等方面优势突出,最近已引起了人们很大的兴趣。本文主要介绍以共轭聚合物为基础的离子荧光化学传感器的近期研究进展,重点综述了共轭聚合物的荧光化学传感器在阳离子识别检测中的分子设计、合成、作用机理和应用,并展望了该领域的发展方向。     

氮掺杂多孔炭材料的制备及在多相催化中的应用

氮掺杂多孔炭材料,不仅具有多孔炭材料的较高的比表面积、丰富的孔结构、良好的稳定性及耐高温耐酸碱性等优点,同时氮原子的引入使材料表现出优异的导电性能及电子传输能力,使得炭材料具有了一定的碱性及催化性能,是目前多相催化及材料领域的一个研究热点。本文综述了氮掺杂多孔炭的制备方法及在多相催化中的应用,并指出了该领域未来研发的重点及应用前景。