Chinese Journal of Chemistry最新文献

Ketenimine zwitterionic salt (KZS), a novel and stable ketenimine precursor, is still underexplored in the realm of chemical synthesis. In this study, we demonstrate the transformation of pyrrole derivatives through the cyclization of KZS with α-aminoketones. The diastereoselectivity of this reaction is influenced by the solvent, enabling the isolation of 3-hydroxypyrrolidine diastereomers with the highest reported dr value of 21 : 1. Furthermore, the chemoselectivity is modulated by the choice of base, yielding 2-aminopyrrole derivatives as the major products. This research offers a sustainable approach to harnessing the potential of KZS in organic synthesis, contributing to a greener chemical process.

The industrialization of organic solar cells (OSCs) faces challenges due to complex synthesis routes and high costs of organic photovoltaic materials. To address this, we designed and synthesized a series of polythiophene-based donor materials, PTVT-T-xCl (20%Cl, 50%Cl and 100%Cl), by introducing different degrees of chlorine substitution within their conjugated skeletons. The incorporation of chlorine atoms does not change the planar conformation of the conjugated main chain of the control polymer, PTVT-T, but effectively reduces their HOMO energy levels (≤ –5.3 eV) and alters the crystallinity of the polymers. In addition, when preparing OSC by blending with non-fused electron acceptor A4T-16, the non-radiative energy loss of the three photovoltaic devices gradually decreased with the increase of chlorine content (0.343, 0.278 and 0.189 eV, respectively). Notably, PTVT-T-20%Cl exhibited a more moderate nanoscale phase separation with the acceptor, leading to efficient exciton dissociation, lower bimolecular recombination, and thus a favorable current in the OSCs. Consequently, the photovoltaic device based on PTVT-T-20%Cl:A4T-16 achieved a remarkable photovoltaic efficiency of 11.8%. In addition, the PTVT-T-xCl series polymers show much lower material-only-cost (MOC) values than the other reported photoactive material systems. This work provides the way for the development of low-cost photovoltaic materials and the industrial application of OSC, overcoming previous limitations posed by high energy losses in polythiophene-based donors.

The present work prepared a copper N-heterocyclic carbene complex that could be used in catalyzing the homogeneous hydrogenation of carboxylic acid with ammonia borane (hydrogen source) to synthesize primary alcohols. Various aromatic and aliphatic carboxylic acids with diverse functional groups were transformed to respective alcohols in moderate to high yields. The process can be easily scaled up (TON up to 14545) and exhibits a high compatibility with different sensitive functional groups, including fluorine, chlorine, bromine, iodine, hydroxyl, cyano and nitro groups. IMesCuCl/NH₃·BH₃ combination can selectively reduce aromatic and aliphatic esters. Mechanistic studies indicate that Cu-H species produced in situ are the active intermediates.

Given the crucial role of film morphology in determining the photovoltaic parameters of organic solar cells (OSCs), solvent or solid additives have been widely used to realize fine-tuned film morphological features to further improve the performance of OSCs. However, most high-performance OSCs are processed only using single component additive, either solvent additive or solid additive. Herein, a simple molecular building block, namely thieno[3,4-b]thiophene (TT), was utilized as the solid additive to coordinate with the widely used solvent additive, 1-chloronaphthalene (CN), to modulate the film morphology. Systematical investigations revealed that the addition of TT could prevent the excessive aggregation to form a delicate nanoscale phase separation, leading to enhanced charge transport and suppressed charge recombination, as well as superior photovoltaic performance. Consequently, the PM6:Y6 based OSCs with the addition of hybrid additive of CN + TT demonstrated the optimal PCE of 18.52%, with a notable FF of 79.6%. More impressively, the PM6:Y6:PC₇₁BM based ternary OSCs treated with the hybrid additives delivered a remarkable efficiency of 19.05%, which ranks among the best values of Y6-based OSCs reported so far. This work highlights the importance of the hybrid additive strategy in regulating the active layer morphology towards significantly improved performance.

Post-polymerization modification provides an important approach to tuning the material properties of obtained polymers. In this work, we demonstrated a rational design of novel vinylcyclopropane monomer bearing a pendant N-hydroxylphthalimide redox ester, and explored its radical ring-opening polymerization behavior under visible-light conditions. Photochemical decarboxylation of resulted polymer provided unique access to poly(vinylcyclopropane) bearing single ester group in each repeating unit. This decarboxylative modification has greatly reshaped the thermal and mechanical properties, converting a glassy polymer into a soft, ductile, and rubber-like material.