Precision Chemistry最新文献

Tetra-coordinate boron-based fluorescent materials hold considerable promise across chemistry, biology and materials science due to their unique and precisely tunable optoelectronic properties. The incorporation of the heteroatom boron (B) enables these materials to exhibit high luminescence quantum yields, adjustable absorption and emission wavelengths, and exceptional photostability. This review examines the molecular design and applications of tetra-coordinate boron-based photoactive molecules, highlighting their roles in fluorescence sensing, anticounterfeiting, and imaging. We outline how structural features impact their properties and discuss strategies for enhancing their performance, including ligand modification and the extension of conjugation length, among others. Additionally, future research focus in this field is also addressed including strategies for diversifying molecular structures and enhancing molecular stability, which is believed to pave the way for innovative solutions to the challenges in areas such as sensing, imaging and information security.

Organic semiconducting nanomembranes (OSNMs), particularly carbon-based ones, are at the forefront of next-generation two-dimensional (2D) semiconductor research. These materials offer remarkable promise due to their diverse chemical properties and unique functionalities, paving the way for innovative applications across advanced semiconductor material sectors. Graphene stands out for its extraordinary mechanical strength, thermal conductivity, and superior charge transport capabilities, inspiring extensive research into other 2D carbon allotropes like graphyne and graphdiyne. With its high electron mobility and tunable bandgap, graphdiyne is particularly attractive for power-efficient electronic devices. However, synthesizing graphdiyne presents significant challenges, primarily due to the difficulty in achieving precise and deterministic control over the coupling of its monomers. This precision is crucial for determining the material's porosity, periodicity, and overall functionality. Innovative approaches have been developed to address these challenges, such as the strategic assembly of molecular building blocks at heterogeneous interfaces. Furthermore, data-driven techniques, such as machine learning and artificial intelligence (AI), are proving invaluable in this field, assisting in screening precursors, optimizing structural configurations, and predicting novel properties of these materials. These advancements are essential for producing durable monolayer sheets that can be integrated into existing electronic components. Despite these advancements, the integration of graphdiyne into semiconductor technology remains complex. Achieving long-range coherence in bonding configurations and enhancing charge transport characteristics are significant hurdles. Continued research into robust and controllable synthesis techniques is essential for unlocking the full potential of graphdiyne and other 2D materials, leading to more efficient, faster, and mechanically robust electronics.

The bibenzyl skeleton is prevalent in numerous natural products and other biologically active compounds. Radical homocoupling provides a straightforward approach for synthesizing bibenzyls in a single step with the reductive homocoupling of benzyl halides undergoing extensive development. Unlike benzyl bromides and other tailored precursors used in visible-light-mediated homocoupling, benzyl chlorides offer greater abundance and chemical stability. Nevertheless, achieving chemoselective cleavage of the C-Cl bond poses significant challenges, with only a limited number of studies reported to date. Herein, we demonstrate a catalytic reductive homocoupling of benzyl chlorides facilitated by zirconocene and photoredox catalysis. This cooperative catalytic system promotes C-Cl bond cleavage in benzyl chlorides under mild conditions and supports the homocoupling of a wide range of benzyl chlorides, including those derived from pharmaceutical agents. Our preliminary mechanistic investigations highlight the pivotal role of hydrosilane in the catalytic cycle.

A highly strained macrocycle comprising four [4]helicene panels, [4]cyclo[4]helicenylene ([4]CH, 1), was synthesized through a one-pot macrocyclization and chemically reduced by alkali metals (Na and K), revealing a four-electron reduction process. The resulting di-, tri-, and tetraanions of compound 1 were isolated and crystallographically characterized by X-ray diffraction. Owing to the four axially chiral bi[4]helicenyl fragments, a reversible stereo transformation of 1 between the (S,R,S,R)- and (S,S,R,R)-configurations was disclosed upon the two-electron uptake, which was rationally understood by theoretical calculations. The (S,S,R,R)-configuration of 1 ^2- was further stabilized in triply reduced and tetra-reduced states, where structural deformation led by charges and metal complexation was observed. This study proposed an approach to alter the configuration of cycloarylenes in addition to thermal treatment.

The one-pot terpolymerization of epoxide (EP), anhydride (AH), and CO₂ to synthesize polyester-polycarbonate copolymers with precise sequences remains a significant challenge in polymer chemistry. In this study, promising progress was achieved by utilizing a cyclic trimeric phosphazene base (CTPB) and triethylboron (TEB) as a binary catalyst, enabling the synthesis of both well-defined block and truly random poly(ester-carbonate) copolymers through the one-pot terpolymerization of EP/AH/CO₂. By adjusting the molar ratio of CTPB/TEB to 1/0.5, remarkable chemoselectivity for ring-opening alternating copolymerization (ROAC) of propylene oxide (PO) and phthalic anhydride (PA) was achieved, followed by the ROAC of PO/CO₂. This sequential control allowed for the synthesis of well-defined block poly(ester-carbonate) copolymers, containing three possible sequences, ester-ester sequence (EE)/ester-carbonate sequence (EC)/carbonate-carbonate sequence (CC) = 59/4/37, from a mixture of PO, PA, and CO₂. Moreover, the versatility of this CTPB/TEB catalyst in regulating chemoselectivity was demonstrated, with a ratio of 1/3 facilitating the simultaneous ROAC of PO/PA and PO/CO₂ with compatible rates, resulting in the production of random poly(ester-carbonate) copolymers, in which three possible sequences (EE/EC/CC = 26/50/24) are very close to theoretical values. This metal-free catalytic system and its flexible chemoselectivity regulation strategy proved to be applicable to a wide range of epoxides (PO, cyclohexene oxide (CHO)) and anhydrides (PA, diglycolic anhydride (DGA), and succinic anhydride (SA)), enabling the successful synthesis of poly(ester-carbonate) copolymers with diverse sequences and compositions.