Asymmetric alkynylation of aldehydes with propiolates without high reagent loading and any additives

The asymmetric alkynylation of aliphatic and aromatic aldehydes with propiolates was mediated by dialkylzinc and a novel prolinol catalyst without high reagent loading and any additives, such as Ti(Oi-Pr)(4), to give the corresponding γ-hydroxy-α,β-acetylenic esters with high enantiomeric excess of up to 95%.     

Thiourea-tagged poly(octadecyl acrylate) gels as fluoride and acetate responsive polymer gels through selective complexation

Fluoride and acetate-responsive polymer gels were prepared by incorporation of p-nitrophenylthiourea into poly(octadecyl acrylate) gels, and the colours and volumes were changed selectively in the presence of these ions by complexation in THF.     

Molecular Design Rule of Phthalocyanine Dyes for Highly Efficient Near‐IR Performance in Dye‐Sensitized Solar Cells

A series of zinc–phthalocyanine sensitizers ( PcS16 – 18 ) with different adsorption sites have been designed and synthesized in order to investigate the dependence of adsorption‐site structures on the solar‐cell performances in zinc–phthalocyanine based dye‐sensitized solar cells. The change of adsorption site affected the electron injection efficiency from the photoexcited dye into the nanocrystalline TiO₂ semiconductor, as monitored by picosecond time‐resolved fluorescence spectroscopy. The zinc–phthalocyanine sensitizer PcS18 , possessing one carboxylic acid directly attached to the ZnPc ring and six 2,6‐diisopropylphenoxy units, showed a record power conversion efficiency value of 5.9 % when used as a light‐harvesting dye on a TiO₂ electrode under one simulated solar condition.     

Control of photochemistry of stilbazolium ion by adsorption to poly(potassium vinylsulfate) and to hectorite clay

Adsorption or intercalation of trans-1-methyl-4-(2-phenylvinyl)pyridinium ion (stilbazolium ion, SB ( 1 )) to a polyelectrolyte, i. e., poly(potassium vinylsulfate) (PVSK), and to a hectorite clay is studied and its effect on the photochemistry of SB examined. trans-cis Photoisomerization of SB molecularly adsorbed to PVSK proceeds efficiently as with free SB in water, while that of SB molecularly intercalated in the clay is markedly suppressed. Photodimerization proceeds efficiently with SB intercalated in the clay in the aggregated form. Overall photodecoloration, however, proceeds more efficiently with SB adsorbed to PVSK under multiple adsorption conditions apparently due to the higher mobility of PVSK-adsorbed SB compared to that of clay-intercalated SB.     

Inside Back Cover: Integrated Soft Porosity and Electrical Properties of Conductive-on-Insulating Metal-Organic Framework Nanocrystals (Angew. Chem. Int. Ed. 35/2023)

A one-stone, two-bird method to integrate the soft porosity and electrical properties of distinct metal–organic frameworks (MOFs) into a single material involves the design of conductive-on-insulating MOF (cMOF-on-iMOF) heterostructures that allow for direct electrical control. Herein, we report the synthesis of cMOF-on-iMOF heterostructures using a seeded layer-by-layer method, in which the sorptive iMOF core is combined with chemiresistive cMOF shells. The resulting cMOF-on-iMOF heterostructures exhibit enhanced selective sorption of CO₂ compared to the pristine iMOF (298 K, 1 bar, S from 15.4 of ZIF-7 to 43.2–152.8). This enhancement is attributed to the porous interface formed by the hybridization of both frameworks at the molecular level. Furthermore, owing to the flexible structure of the iMOF core, the cMOF-on-iMOF heterostructures with semiconductive soft porous interfaces demonstrated high flexibility in sensing and electrical “shape memory” toward acetone and CO₂. This behavior was observed through the guest-induced structural changes of the iMOF core, as revealed by the operando synchrotron grazing incidence wide-angle X-ray scattering measurements.