Hydrogenolysis of the half‐sandwich penta‐arylcyclopentadienyl‐supported heavy alkaline‐earth‐metal alkyl complexes (CpAr)Ae[CH(SiMe3)2](S) (CpAr=C5Ar5, Ar=3,5‐iPr2‐C6H3; S=THF or DABCO) in hexane afforded the calcium, strontium, and barium metal–hydride complexes as the same dimers [(CpAr)Ae(μ‐H)(S)]2 (Ae=Ca, S=THF, 2‐Ca; Ae=Sr, Ba, S=DABCO, 4‐Ae), which were characterized by NMR spectroscopy and single‐crystal X‐ray analysis. 2‐Ca, 4‐Sr, and 4‐Ba catalyzed alkene hydrogenation under mild conditions (30 °C, 6 atm, 5 mol % cat.), with the activity increasing with the metal size. A variety of activated alkenes including tri‐ and tetra‐substituted olefins, semi‐activated alkene (Me3SiCH=CH2), and unactivated terminal alkene (1‐hexene) were evaluated.
This study obtained solution-tractable anion-selective membranes with intrinsic porous and highly ionic conductive capabilities by a convenient route. We used the coplanar structure of 9,9-dimethylxanthene to construct a rigid twisted intrinsic microporous all-carbon skeleton PDI with up to 363.4 m 2 g −1 of Brunauer−Emmett−Teller surface, and the pore was filled with a quaternary ammonium salt containing long flexible alkyl chains, which produced an efficient means of OH − transport. The conductivity of the resulting polymer (QPDI-100) is reached as high as 205 mS cm −1 at 80 °C. The size stability was determined to be good at high conductance and swelling ratio is less than 15% at 80 °C. QPDI-a exhibited good stability under alkaline conditions, and 90% of the conductivity of QPDI-100 was retained after being immersed in 1 M NaOH solution at 60 °C for 40 days. The power density of H 2 −O 2 fuel cells at 60 °C was 437.7 mW cm −2 . The prepared intrinsic porous anion exchange membranes (AEMs) demonstrate potential for the development of anion exchange membrane fuel cells. This membrane design strategy paves the way for a new generation of AEMs for the purposes of electrochemical energy conversion and storage.
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