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1. A New Platform of B/N‐Doped Cyclophanes: Access to a π‐Conjugated Block‐Type B 3 N 3 Macrocycle with Strong Dipole Moment and Unique Optoelectronic Properties

   https://doi.org/10.1002/ange.202200612  

   Li, Pengfei ; Shimoyama, Daisuke ; Zhang, Niu ; Jia, Yawei ; Hu, Guofei ; Li, Chenglong ; Yin, Xiaodong ; Wang, Nan ; Jäkle, Frieder ; Chen, Pangkuan ( March 2022 , Angewandte Chemie)

   We herein describe a new design principle to achieve B/N‐doped cyclophane where an electron‐donor block of three triarylamines (Ar₃N) and an acceptor block of three triarylboranes (Ar₃B) are spatially separated on opposite sides of the π‐extended ring system. DFT computations revealed the distinct electronic structure of theblock‐type macrocycleMC‐b‐B3N3with a greatly enhanced dipole moment and reduced HOMO–LUMO energy gap in comparison to its analogue with alternating B and N sites,MC‐alt‐B3N3. The unique arrangement of borane acceptor Ar₃B and amine donor Ar₃N components inMC‐b‐B3N3induces exceptionally strong intramolecular charge transfer in the excited state, which is reflected in a largely red‐shifted luminescence at 612 nm in solution. The respective linear open‐chain oligomerL‐b‐B3N3was also synthesized for comparison. Our new approach to donor–acceptor macrocycles offers important fundamental insights and opens up a new avenue to unique optoelectronic materials.

    

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2. Copolymer‐Derived N/B Co‐Doped Nanocarbons with Controlled Porosity and Highly Active Surface

   https://doi.org/10.1002/pol.20190002  

   Yuan, Rui ; Wang, Han ; Sun, Mingkang ; Whitacre, Jay ; Matyjaszewski, Krzysztof ; Kowalewski, Tomasz ( January 2020 , Journal of Polymer Science)

   N/B co‐doped nanocarbon (NBC) is emerging as promising candidate in various applications. However, most synthetic approaches require complex heteroatom/carbon precursors, and suffer from poor porosity control and inevitable formation of electrochemically inactive N─B bonded species. In this study, we propose a new route to produce NBC from a single copolymer precursor, polyacrylonitrile‐b‐poly(styrene boronic ester) (PAN‐b‐PSBpin). Both polymeric blocks play dual roles during pyrolysis, i.e., PAN serves as both a carbon source and nitrogen source, and PSBpin functions as both a boron source and porogenic block. Importantly, a linear relationship between mesopore size in NBC and block length in copolymers was observed, allowing for excellent porosity control in NBC. X‐ray photoelectron spectroscopy revealed only separated N and B configurations in formed NBC, assuring highly active surface examined by an efficient four‐electron transfer process in oxygen reduction reaction and large geometric capacitances (C_sa= 68 μF cm⁻²andC_vol= 750 F cm⁻³) in supercapacitors. © 2020 Wiley Periodicals, Inc. J. Polym. Sci.2020,58, 225–232

    

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3. A Heterogeneous Palladium Catalyst for the Polymerization of Olefins Prepared by Halide Abstraction Using Surface R 3 Si + Species

   https://doi.org/10.1002/ange.202117279  

   Gao, Jiaxin ; Dorn, Rick W. ; Laurent, Guillaume P. ; Perras, Frédéric A. ; Rossini, Aaron J. ; Conley, Matthew P. ( March 2022 , Angewandte Chemie)

   The silylium‐like surface species [ⁱPr₃Si][(R^FO)₃Al−OSi≡)] activates (N^N)Pd(CH₃)Cl (N^N=Ar−N=CMeMeC=N−Ar, Ar=2,6‐bis(diphenylmethyl)‐4‐methylbenzene) by chloride ion abstraction to form [(N^N)Pd−CH₃][(R^FO)₃Al−OSi≡)] (1). A combination of FTIR, solid‐state NMR spectroscopy, and reactions with CO or vinyl chloride establish that1shows similar reactivity patterns as (N^N)Pd(CH₃)Cl activated with Na[B(Ar^F)₄]. Multinuclear¹³C{²⁷Al} RESPDOR and¹H{¹⁹F} S‐REDOR experiments are consistent with a weakly coordinated ion‐pair between (N^N)Pd−CH₃⁺and [(R^FO)₃Al−OSi≡)].1catalyzes the polymerization of ethylene with similar activities as [(N^N)Pd−CH₃]⁺in solution and incorporates up to 0.4 % methyl acrylate in copolymerization reactions.1produces polymers with significantly higher molecular weight than the solution catalyst, and generates the highest molecular weight polymers currently reported in copolymerization reactions of ethylene and methylacrylate.

    

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4. A Heterogeneous Palladium Catalyst for the Polymerization of Olefins Prepared by Halide Abstraction Using Surface R 3 Si + Species

   https://doi.org/10.1002/anie.202117279  

   Gao, Jiaxin ; Dorn, Rick W. ; Laurent, Guillaume P. ; Perras, Frédéric A. ; Rossini, Aaron J. ; Conley, Matthew P. ( March 2022 , Angewandte Chemie International Edition)

   The silylium‐like surface species [ⁱPr₃Si][(R^FO)₃Al−OSi≡)] activates (N^N)Pd(CH₃)Cl (N^N=Ar−N=CMeMeC=N−Ar, Ar=2,6‐bis(diphenylmethyl)‐4‐methylbenzene) by chloride ion abstraction to form [(N^N)Pd−CH₃][(R^FO)₃Al−OSi≡)] (1). A combination of FTIR, solid‐state NMR spectroscopy, and reactions with CO or vinyl chloride establish that1shows similar reactivity patterns as (N^N)Pd(CH₃)Cl activated with Na[B(Ar^F)₄]. Multinuclear¹³C{²⁷Al} RESPDOR and¹H{¹⁹F} S‐REDOR experiments are consistent with a weakly coordinated ion‐pair between (N^N)Pd−CH₃⁺and [(R^FO)₃Al−OSi≡)].1catalyzes the polymerization of ethylene with similar activities as [(N^N)Pd−CH₃]⁺in solution and incorporates up to 0.4 % methyl acrylate in copolymerization reactions.1produces polymers with significantly higher molecular weight than the solution catalyst, and generates the highest molecular weight polymers currently reported in copolymerization reactions of ethylene and methylacrylate.

    

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5. An experimental and computational study of donor–linker–acceptor block copolymers for organic photovoltaics

   https://doi.org/10.1002/polb.24633  

   Hu, Zhiqi ; Jakowski, Jacek ; Zheng, Chenyu ; Collison, Christopher J. ; Strzalka, Joseph ; Sumpter, Bobby G. ; Verduzco, Rafael ( August 2018 , Journal of Polymer Science Part B: Polymer Physics)

   Block copolymers with donor and acceptor conjugated polymer blocks provide an approach to dictating the donor–accepter interfacial structure and understanding its relationship to charge separation and photovoltaic performance. We report the preparation of a series of donor‐linker‐acceptor block copolymers with poly(3‐hexylthiophene) (P3HT) donor blocks, poly((9,9‐dioctylfluorene)‐2,7‐diyl‐alt‐[4,7‐bis(thiophen‐5‐yl)‐2,1,3‐benzothiadiazole]‐2′,2″‐diyl) (PFTBT) acceptor blocks, and varying lengths of oligo‐ethylene glycol (OEG) chains as the linkers. Morphological analysis shows that the linkers increase polymer crystallinity while a combination of optical and photovoltaic measurements shows that the insertion of a flexible spacer reduces fluorescence quenching and photovoltaic efficiencies of solution processed photovoltaic devices. Density functional theory (DFT) simulations indicate that the linking groups reduce both charge separation and recombination rates, and block copolymers with flexible linkers will likely rotate to assume a nonplanar orientation, resulting in a significant loss of overlap at the donor–linker–acceptor interface. This work provides a systematic study of the role of linker length on the photovoltaic performance of donor–linker–acceptor block copolymers and indicates that linkers should be designed to control both the electronic properties and relative orientations of conjugated polymers at the interface. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2018,56, 1135–1143

    

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