More Like this

1. Carving Out Pores in Redox‐Active One‐Dimensional Coordination Polymers

   https://doi.org/10.1002/ange.201807506  

   Clayman, Naomi E. ; Manumpil, Mary Anne ; Umeyama, Daiki ; Rudenko, Andrey E. ; Karunadasa, Hemamala I. ; Waymouth, Robert M. ( September 2018 , Angewandte Chemie)

   Reduction of the insulating one‐dimensional coordination polymer [Cu(abpy)PF₆]_n,1 a(PF₆), (abpy=2,2′‐azobispyridine) yields the conductive, porous polymer [Cu(abpy)]_n,2 a. Pressed pellets of neutral2 aexhibit a conductivity of 0.093 S cm⁻¹at room temperature and a Brunauer–Emmett–Teller (BET) surface area of 56 m² g⁻¹. Fine powders of2 ahave a BET surface area of 90 m² g⁻¹. Cyclic voltammetry shows that the reduction of1 a(PF₆) to2 ais quasi‐reversible, indicative of facile charge transfer through the bulk material. The BET surface area of the reduced polymer2can be controlled by changing the size of the counteranion X in the cationic [Cu(abpy)X]_n. Reduction of [Cu(abpy)X]_nwith X=Br (2 b) or BAr^F(2 c; BAr^F=tetrakis(3,5‐bis(trifluoromethyl)phenyl)), affords [Cu(abpy)]_npolymers with surface areas of 60 and 200 m² g⁻¹, respectively.

    

   more » « less
2. Phosphonium‐based polyelectrolyte networks with high thermal stability, high alkaline stability, and high surface areas

   https://doi.org/10.1002/pola.29298  

   Yang, Xiaoyan ; Smith, Rhett C. ( December 2018 , Journal of Polymer Science Part A: Polymer Chemistry)

   Phosphonium‐containing polyelectrolyte networks (PENs) (P1–P4) were prepared by cyclotrimerization of bis(4‐acetylphenyl)diphenylphosphonium bromide (M1) and 1,4‐diacetylbenzene (M2) withp‐toluene sulfonic acid in variousM1:M2ratios (1,0, 1:1, 1:2, and 1:4). The relative abundance of the PAr₄⁺units in each PEN was demonstrated to influence thermal stability, alkaline stability, water uptake, surface area, and CO₂uptake in predictable ways. Impressively, PENs with NTf₂⁻counterions (Tf = CF₃SO₃) did not exhibit 5% mass loss until heating above 400 °C. Alkaline stability, tested by challenging a PEN with 6MNaOH(aq) at 65 °C for 120 h, increased with increasing PAr₄⁺content, which reflected the enhanced reactivity of the HO⁻anion in more hydrophobic materials (i.e., PENs with lowerM1:M2ratios). The specific surface areas estimated by Brunauer‐Emmett‐Teller (BET) analysis for these PENs were above 60 m²/g under N₂and nearly 90 m²/g under CO₂. Notably,P3(in which 33% of monomers comprise a phosphonium moiety) exhibited a CO₂uptake affinity of one CO₂molecule adsorbed for every phosphonium site. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2019,57, 598–604

    

   more » « less
3. Redox‐triggered chiroptical switching activity of ruthenium(III)‐bis‐(β‐diketonato) complexes bearing a bipyridine‐helicene ligand

   https://doi.org/10.1002/chir.22835  

   Saleh, Nidal ; Vanthuyne, Nicolas ; Bonvoisin, Jacques ; Autschbach, Jochen ; Srebro‐Hooper, Monika ; Crassous, Jeanne ( March 2018 , Chirality)

   The charged, electroactive bipyridine‐helicene‐ruthenium(III) complex [4]^.+,PF₆⁻has been prepared from 3‐(2‐pyridyl)‐4‐aza[6]helicene and a Ru‐bis‐(β‐diketonato)‐bis‐acetonitrile precursor (β‐diketonato: 2,2,6,6‐tetramethyl‐3,5‐heptanedionato). Its chiroptical properties (electronic circular dichroism and optical rotation) were studied both experimentally and theoretically and suggest the presence of 2 diastereoisomers, namely (P,Δ)‐ and (P,Λ)‐[4]^.+,PF₆⁻(denoted jointly as (P,Δ*)‐[4]^.+,PF₆⁻) and their mirror‐images (M,Λ)‐ and (M,Δ)‐[4]^.+,PF₆⁻((M,Δ*)‐[4]^.+,PF₆⁻). The electrochemical reduction of (P,Δ*)‐[4]^.+,PF₆⁻to neutral complex (P,Δ*)‐4was performed and revealed strong changes in the UV‐vis and electronic circular dichroism spectra. A reversible redox‐triggered chiroptical switching process was then achieved.

    

   more » « less
4. Further Studies of Co III (TIM) Mono‐Alkynyl and Bis‐Alkynyl Complexes

   https://doi.org/10.1002/ejic.202200641  

   Rodriguez Segura, Leobardo ; Cox, Kenneth E. ; Samayoa‐Oviedo, Hugo Y. ; Ren, Tong ( December 2022 , European Journal of Inorganic Chemistry)

   A new series of mono‐ and bis‐alkynyl Co^III(TIM) complexes (TIM=2,3,9,10‐tetramethyl‐1,4,8,11‐tetraazacyclotetradeca‐1,3,8,10‐tetraene) is reported herein. Thetrans‐[Co(TIM)(C₂R)Cl]⁺complexes were prepared from the reaction betweentrans‐[Co(TIM)Cl₂]PF₆and HC₂R (R=tri(isopropyl)silyl or TIPS (1), ‐C₆H₄‐4‐^tBu (2), ‐C₆H₄‐4‐NO₂(3 a), andN‐mesityl‐1,8‐naphthalimide or NAP^Mes(4 a)) in the presence of Et₃N. The intermediate complexes of the typetrans‐[Co(TIM)(C₂R)(NCMe)](PF₆)(OTf),3 band4 b, were obtained by treating3 aand4 a, respectively, with AgOTf in CH₃CN. Furthermore, bis‐alkynyltrans‐[Co(TIM)(C₂R)₂]PF₆complexes,3 cand4 c, were generated following a second dehydrohalogenation reaction between3 band4 b, respectively, and the appropriate HC₂R in the presence of Et₃N. These new complexes have been characterized using X‐ray diffraction (2,3 a,4 a, and4 c), IR,¹H NMR, UV/Vis spectroscopy, fluorescent spectroscopy (4 c), and cyclic voltammetry.

    

   more » « less
5. Dispersion‐Force‐Assisted Disproportionation: A Stable Two‐Coordinate Copper(II) Complex

   https://doi.org/10.1002/ange.201605061  

   Wagner, Clifton L. ; Tao, Lizhi ; Thompson, Emily J. ; Stich, Troy A. ; Guo, Jingdong ; Fettinger, James C. ; Berben, Louise A. ; Britt, R. David ; Nagase, Shigeru ; Power, Philip P. ( July 2016 , Angewandte Chemie)

   The synthesis of the first linear coordinated Cu^IIcomplex Cu{N(SiMe₃)Dipp}₂(1Dipp=C₆H₅‐2,6Prⁱ₂) and its Cu^Icounterpart [Cu{N(SiMe₃)Dipp}₂]⁻(2) is described. The formation of1proceeds through a dispersion force‐driven disproportionation, and is the reaction product of a Cu^Ihalide and LiN(SiMe₃)Dipp in a non‐donor solvent. The synthesis of2is accomplished by preventing the disproportionation into1by using the complexing agent 15‐crown‐5. EPR spectroscopy of1provides the first detailed study of a two‐coordinate transition‐metal complex indicating strong covalency in the Cu−N bonds.

    

   more » « less