Two donor–acceptor copolymers based on isomeric acceptor units, [7,7′‐bithieno[2′,3′:4,5]thieno[2,3‐d ]thieno[3,2‐b ]pyridine]‐5,5′(4H ,4′H )‐dione (BTTP) and [2,2′‐bithieno[2′,3′:4,5]thieno[2,3‐d ]thieno[3,2‐b ]pyridine]‐5,5′(4H ,4′H )‐dione (iBTTP), are developed to study the effect of isomeric structures on photovoltaic performance. Compared with PBDTBTTP, PBDTiBTTP possesses a smaller bandgap for good light harvesting and a better π–π stacking for higher hole mobility. PBDTiBTTP solar cells present balanced mobilities and good nanoscale phase separation, giving a power conversion efficiency (PCE) of 6.51%, with higher short‐circuit current (J sc) and fill factor (FF).
Triptycene‐based micorporous polymer is functionalized with CO2‐philic tetrazole moieties via ZnCl2‐catalyzed post‐polymerization. Gas adsorption experiments indicate that it possesses high CO2 uptake capacity, reaching 134 cm3 g−1 (26.5 wt%) at 1.0 bar and 273 K, along with high selectivity towards CO2 over N2 and CH4. The porous polymeric networks present the promising potentials as efficient adsorbents in clean energy applications.
Two novel tetra‐armed microporous organic polymers have been designed and synthesized via a nickel‐catalyzed Yamamoto‐type Ullmann cross‐coupling reaction or Suzuki cross‐coupling polycondensation. These polymers are stable in various solvents, including concentrated hydrochloric acid, and are thermally stable. The homocoupled polymer YPTPA shows much higher Brunauer–Emmet–Teller‐specific surface area up to 1557 m2 g−1 than the copolymer SPTPA (544 m2 g−1), and a high CO2 uptake ability of 3.03 mmol g−1 (1.13 bar/273 K) with a CO2/N2 sorption selectivity of 17.3:1. Both polymers show high isosteric heats of CO2 adsorption (22.7–26.5 kJ mol−1) because the incorporation of nitrogen atoms into the skeleton of microporous organic polymers enhances the interaction between the pore wall and the CO2 molecules. The values are higher than those of the porous aromatic frameworks, which contain neither additional polar functional groups nor nitrogen atoms, and are rather close to those of previously reported microporous organic polymers containing the nitrogen atoms on the pore wall. These data show that these materials would be potential candidates for applications in post‐combustion CO2 capture and sequestration technology.
High‐molecular‐weight conjugated polymer HD‐PDFC‐DTBT with N‐(2‐hexyldecyl)‐3,6‐difluorocarbazole as the donor unit, 5,6‐bis(octyloxy)benzothiadiazole as the acceptor unit, and thiophene as the spacer is synthesized by Suzuki polycondensation. HD‐PDFC‐DTBT shows a large bandgap of 1.96 eV and a high hole mobility of 0.16 cm2 V−1 s−1. HD‐PDFC‐DTBT:PC71BM‐based inverted polymer solar cells (PSCs) give a power conversion efficiency (PCE) of 7.39% with a Voc of 0.93 V, a Jsc of 14.11 mA cm−2, and an FF of 0.56.
Five three‐component chiral polymers incorporating (S )‐1,1′‐binaphthyl, tetraphenylethene (TPE) and fluorene moieties are designed and synthesized by Pd‐catalyzed Sonogashira reaction. All these polymers show obvious aggregation induced emission enhancement response behavior in the fluorescence emission region of 460–480 nm. Interestingly, three of them show aggregation‐induced circularly polarized luminescence (AICPL) signals in tetrahydrofuran–H2O mixtures. Most importantly, these AICPL signals can be tuned by changing the molar ratios of TPE and fluorene components through fluorescence resonance energy transfer and give the highest glum = ±4.0 × 10−3. This work provides a novel strategy for developing AICPL‐enhanced materials.
We report the first mass spectrometric analysis of poly(ionic liquid)s (PILs) containing weakly coordinating anions introduced by a fast, simple, and quantitative postmodification method on the example of the hydrophilic, well‐defined poly(vinylbenzylpyridinium chloride) p([VBPy]Cl) species, analyzed with an in‐source collision induced dissociation‐Orbitrap mass spectrometry (MS) protocol. Using the MS approach allows for the precise structural elucidation of ion‐exchanged p([VBPy]Cl) utilizing AgX (X = NO3−, CF3CO2−, BF4−) salts. The anion exchange is shown to be quantitative – without observing residual chlorinated PIL – on rapid time scales, using only filtration as a standard procedure during sample preparation. In addition, the influence of weakly coordinating anions on the ionization behavior of PILs is studied in detail.
A heterotritopic copillar[5]arene monomer by introducing effective neutral guest moieties (methylene chains end‐capped with cyano and triazole groups) to a pillar[5]arene macrocycle is prepared. This well‐designed AB2‐type copillar[5]arene contains strong host–guest recognition motifs that are connected with relatively flexible and long linkers, thus efficiently assembles to form supramolecular hyperbranched polymer (SHP) in chloroform solution, which is characterized by various techniques including 1H NMR, DOSY, viscosity, DLS, and TEM. Particularly, this supramolecular polymer can be effectively depolymerized by adding a competitive butanedinitrile guest.
Two novel copolymers based on benzothiadiazole (BT) or difluorobenzothiadizole (ffBT) with 2,2′‐(perfluoro‐1,4‐phenylene)dithiophene (2TPF4), namely PBT‐2TPF4 and PffBT‐2TPF4, are synthesized for applications in polymer solar cells (PSCs). A noticeably high open‐circuit voltage (V oc) of 1.017 and 0.87 V are achieved for PffBT‐2TPF4 and PBT‐2TPF4‐based devices, respectively. Although only a moderate efficiency (5.7%) of PBT‐2TPF4‐based devices is obtained, it is first demonstrated that 2TPF4 is a promising acceptor block for construction of the donor copolymers which possess high V oc, prominent crystallinity, and long‐term stability, simultaneously. Besides, two thienyl flanking the tetrafluorophenylene can decrease torsion angle between conjugated units, resulting in a high coplanar structure of copolymers to enhance their charge carrier mobility. The findings may open a promising and practical way to accelerate the commercialization of PSCs by developing a series of new donor copolymers for efficient and long‐term stable thickness bulk heterojunction PSCs.
The fluorinated FI–Ti catalyst bis[N‐(3‐propylsalicylidene)‐pentafluoroanilinato] titanium(IV) dichloride (PFI) combined with dried methylaluminoxane (dMAO) is investigated for ethylene/1‐hexene copolymerization at 50 °C under atmospheric pressure. The reaction shows good livingness and has a high activity at high [H]/[E] molar ratios up to 14. Ultrahigh molecular weight (>1.4 × 106 g mol−1) copolymers with high 1‐hexene content (>25 mol%) are prepared. Kinetic parameters of the copolymerization with PFI are determined. The first‐order Markov statistics applies and the product of the reactivity ratios r1r2 is close to 1, giving random unit distributions.
A novel route for the synthesis of poly(ethylene glycol)‐b‐polystyrene copolymer, starting from commercially available poly(ethylene glycol) methyl ether and azido terminated polystyrene prepared by atom transfer radical polymerization and subsequent nucleophilic substitution, is applied with simplicity and high efficiency. The combination of photoinduced copper (I)‐catalyzed alkyne‐azide cycloaddition (CuAAC) and ketene chemistry reactions proceeds either simultaneously or sequentially in a one‐pot procedure under near‐visible light irradiation. In both cases, excellent block copolymer formations are achieved, with an average molecular weight of around 7000 g mo1−1 and a polydispersity index of 1.20.
Conjugated pillar[5]arene‐diketopyrrolopyrrole copolymer ( P1 ) is synthesized by the copolymerization of a difunctionalized pillar[5]arene and a diketopyrrolopyrrole‐based monomer, which shows large extinction coefficients (1.1 × 104m –1 cm–1) at 519 nm and strong emission at 587 nm. P1 exhibits very strong host–guest binding affinity towards adiponitrile but low binding affinity towards 1,4‐dihalobutane and 1,4‐bis(imidazol‐1‐yl)butane. Such an enhanced selectivity is first found in the polypseudorotaxane between pillararene and neutral guests in organic solution and is successfully used for the recognition and adsorption of adiponitrile by the formation of a P1 ‐adiponitrile polypseudorotaxane.
An alkyne‐functionalized ruthenium(II) bis‐terpyridine complex is directly copolymerized with phenylacetylene by alkyne polymerization. The polymer is characterized by size‐exclusion chromatography (SEC), 1H NMR spectroscopy, cyclic voltammetry (CV) measurements, and thermal analysis. The photophysical properties of the polymer are studied by UV–vis absorption spectroscopy. In addition, spectro‐electrochemical measurements are carried out. Time‐resolved luminescence lifetime decay curves show an enhanced lifetime of the metal complex attached to the conjugated polymer backbone compared with the Ru(tpy)22+ model complex.
A switch from carbanions to aza‐anions is performed by the addition of N‐tosylaziridine (TAz) to living poly(styryl) (PS) chains. This is the first example of carbanionic aziridine ring‐opening which was previously activated by amidation with a tosyl group to enable nucleophilic ring‐opening by the living chain end. Poly(styrene)‐tosylaziridines (PS‐TAz) with narrow molecular weight distributions and variable molecular weights are synthesized. The removal of the tosyl group and subsequent functionalization is shown, evidencing quantitative transfer to azaanionic species. All polymers are characterized in detail by 1H NMR spectroscopy, DOSY 1H NMR spectroscopy, and size exclusion chromatography (SEC). This strategy allows the introduction of amine groups via anionic polymerization in analogy to the well‐established epoxide termination.
In this article, a synthetic concept for the preparation of polyamides with functional side groups is described. First, the synthesis of a bis(thiolactone) monomer is shown in a concise three‐step route from itaconic acid and DL‐homocysteine thiolactone. The reactivity of the resulting bis(thiolactone) toward hexyl amine is examined. Next, the bis(thiolactone) is reacted as A,A‐type monomer with different B,B‐type comonomers (1,12‐diaminododecane and 1,3‐bis(aminopropyl)tetramethyldisiloxane). Ring opening of the thiolactones by the diamines leads to polyamides with pendant thiol groups. Using two diamines in different ratios, the properties of the resulting polyamides are tuned (thermal properties are determined) and different molecular weights are acquired. Subsequently, the thiol groups are reacted with methyl acrylate via Michael addition to functionalize the polyamides. Functionalization of thiol‐functional polyamides using poly(ethylene glycol) monomethyl ether (mPEG) acrylates ( = 480 and 1700 g mol−1) results in water‐soluble amphiphilic polyamides with molecular weights higher than 10 000 g mol−1.
Pentacyclic lactam acceptor unit TPTI invented by our group is proved to be a good building block for efficient D‐A copolymers used in organic solar cells. Here, two D‐A copolymers PBTTPTI and PTTTPTI are developed by copolymerizing TPTI with 2,2′‐bithiophene (BT) or thieno[3,2‐b]thiophene (TT). PBTTPTI and PTTTPTI exhibit good solubility and strong interchain π–π interaction even in dilute solution. They possess deep HOMO levels (ca. ‐5.3 eV), partial crystallinity, and good hole mobilities. Blending with PC71BM, PBTTPTI and PTTTPTI give decent power conversion efficiencies (PCE) up to 6.83% and 5.86%, with outstanding fill factors (FF) of 74.3% and 71.3%, respectively.
A series of fluorene‐based conjugated polymers containing the aggregation‐induced emissive (AIE)‐active tetraphenylethene and dicarboxylate pseudocrown as a receptor exhibits a unique dual‐mode sensing ability for selective detection of lead ion in water. Fluorescence turn‐off and turn‐on detections are realized in 80%–90% and 20% water in tetrahydrofuran (THF), respectively, for lead ion with a concentration as low as 10−8 m .
This study aims at physicochemical properties of thermo‐ and pH/CO2‐responsive cyclic homopolymers. Three examples of cyclic poly(2‐(dimethylamino)ethyl methacrylate)s (PDMAs) are synthesized by combining the reversible addition–fragmentation chain transfer process and the Diels–Alder ring‐closure reaction. After cyclization, the glass transition temperature significantly increases (ΔTg = 51.8–59.7 °C) due to the different configurational entropy and end groups, and the maximum decomposition temperature to lose the pendent groups is drastically decreased from 309 to 278 °C. Effects of polymerization degree, polymer concentration, additive of NaCl, and pH/CO2 on lower critical solution temperature behaviors of PDMA aqueous solutions are investigated. The cloud points (Tc) of ring PDMAs are usually higher than their linear precursors, and the ΔTc values obtained under a fixed condition can reach up to 20.7 °C, revealing the crucial role of the topology effect. This study paves the way for unique properties and applications of smart cyclic polymers and their derivatives.
Composite nanoparticles from poly[(9,9‐di‐n‐octylfluoren‐2,7‐diyl)‐alt‐(benzo[2,1,3]thiadiazol‐4,8‐diyl)] (F8BT) and poly(9,9‐di‐n‐hexylfluoren‐2,7‐diyl) (PF) with embedded inorganic nanoparticles (TiO2, CdSe, and CdSe/CdS) are prepared through kinetic trapping by rapid turbulent mixing in a multi‐inlet vortex mixer without the need for polymer functionalization. High contents of inorganic materials up to 50–60 wt% are realized for all composites. The influence of flow ratios, sodium dodecyl sulfate (SDS) concentration, and absolute flow rates on the particle size and morphology is studied. High water‐to‐THF ratios and high total flow rates around 2 m s−1 yield particle sizes below 50 nm. By adjusting these parameters, controlled particle sizes between 30 to several hundred nanometers are obtained. Composite particles from CdSe/CdS and F8BT or PF show a strong quenching of the polymer emission and near exclusive emission from the inorganic nanocrystal, which indicates an efficient energy transfer with fluorescence quantum yields of 23% for the F8BT/CdSe/CdS composites and 21% for the PF/CdSe/CdS composites. The dispersions are colloidally stable for several months.
PFpP macromolecules, synthesized via migration insertion polymerization of CpFe(CO)2(CH2)3PPh2 (FpP), exhibit reactive Fp end groups for further migration insertion reactions in the presence of phosphines. A number of alkyl diphenylphosphines with varied alkyl length, Ph2PCn (n = 6, 10, 18), have been prepared for the reaction, resulting in PFpP‐PPh2Cn (n = 6, 10, 18) amphiphiles. The phosphines with longer alkyl chains impose steric hindrance for the reaction and therefore require longer reaction times and excess phosphines relative to PFpP.
A direct and facile route toward semitelechelic polymers, end‐functionalized with palladated sulfur–carbon–sulfur pincer (PdII‐pincer) complexes is reported that avoids any post‐polymerization step. Key to our methodology is the combination of reversible addition‐fragmentation chain‐transfer (RAFT) polymerization with functionalized chain‐transfer agents. This strategy yields Pd end‐group‐functionalized materials with monomodal molar mass dispersities (Đ ) of 1.18–1.44. The RAFT polymerization is investigated using a PdII‐pincer chain‐transfer agent for three classes of monomers: styrene, tert‐butyl acrylate, and N‐isopropylacrylamide. The ensuing PdII‐pincer end‐functionalized polymers are analyzed using 1H NMR spectroscopy, gel‐permeation chromatography, and elemental analysis. The RAFT polymerization methodology provides a direct pathway for the fabrication of PdII‐pincer functionalized polymers with complete end‐group functionalization.
