Monthly Archives: March 2024

Achieving Seconds‐to‐Hours Duration‐Tunable Organic Long Persistent Luminescence from Carbon Dots‐Based Exciplex Systems by Energy Gaps Regulation

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Achieving Seconds-to-Hours Duration-Tunable Organic Long Persistent Luminescence from Carbon Dots-Based Exciplex Systems by Energy Gaps Regulation†

Carbon dots (CDs)-based long persistent luminescence (LPL) composites with a tunable duration in an ultrawide range from second- to hour-level are designed and prepared for the first time. The relationship of energy levels between excited states of CDs and charged-transfer (CT) states of the corresponding composites plays a pivotal role in activating LPL and regulating the LPL durations. These LPL composites have been preliminarily employed in dynamic displaying systems.


Comprehensive Summary

Duration-tunable afterglow materials have garnered considerable attention in various applications. Herein, carbon dots (CDs)-based long persistent luminescence (LPL) composites with a tunable duration in an ultrawide range of seconds-to-hours levels were designed and prepared for the first time. In contrast to the established CD-based afterglow materials, we reported that CD-based composites exhibit LPL in the form of exciplexes and long-lived charge-separated states, enabling the LPL to be prolonged from several seconds to over one hour, exceeding the typical regulation range (limited to 1 min). Further studies revealed that the relationship between the excited and charge-transfer states of CDs plays a pivotal role in activating the LPL and regulating its duration. Furthermore, these composites exhibited high photoluminescence (PL) quantum yields of up to 60.63%, and their LPL was robust under ambient conditions, even in aqueous media. Their robust and superior LPL performance endows these composites with a strong competitive advantage in dynamic display systems, such as tags for time-resolved data encryption and displays of the remaining time of takeaways. This study offers an approach to preparing CDs-based LPL composites with tunable durations and may provide new insights for the development of rare-earth-free LPL materials.

Non‐Fully Conjugated Photovoltaic Materials with Y‐Series Acceptor Backbone for High‐Performance Organic Solar Cells

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Non-Fully Conjugated Photovoltaic Materials with Y-Series Acceptor Backbone for High-Performance Organic Solar Cells†


Comprehensive Summary

In the last few years, organic solar cells (OSCs) have made significant progress in photovoltaic performance, mainly due to the innovative development of active layer materials, especially Y-series and related derivatives as acceptors which have become the key factor that boosts the power conversion efficiency. Recently, to achieve high-performance OSCs, an emerging molecular design strategy of applying flexible alkyl units as linkers to construct non-fully conjugated acceptors has been developed and addressed great attention. This review highlights the non-fully conjugated photovoltaic materials with Y-series backbone that enable high-performance OSCs. Impressive OSCs have been achieved by some representative non-fully conjugated material systems. The related molecular design strategies are discussed in detail. Finally, a brief summary and future prospect are provided in advancing the non-fully conjugated photovoltaic materials with Y-series backbone towards the brighter future.

Key Scientists

Formal synthesis of 10‐Hydroxy‐6‐Aryldibenzo[b,g][1,8]Naphthyridin‐11(6H)‐ones from 2‐chloroquinolin‐3‐carbaldehydes and 3‐(Arylamino)cyclohexenones

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Formal synthesis of 10-Hydroxy-6-Aryldibenzo[b,g][1,8]Naphthyridin-11(6H)-ones from 2-chloroquinolin-3-carbaldehydes and 3-(Arylamino)cyclohexenones

Two component synthesis of naphthyridines.


Abstract

We have described herein a simple and formal synthesis of 10-Hydroxy-6-Aryldibenzo[b,g][1,8]naphthyridin-11(6H)-ones from 2-chloroquinolin-3-carbaldehydes and 3-(Arylamino)cyclohexenones. This protocol provides the formation of four rings including 1,8-naphthyridin under the mild conditions. Furthermore, the cyclohexanone part of the enaminone undergoes air oxidation provided the phenol ring is attached directly to the 1,8-naphthyridin scaffold. These newly formed chemo-types may be useful in drug discovery programs probably as antibacterial agents due to the presence of 1,8-naphthyridine.

Unraveling complexation and enantioseparation of a new chiral‐at‐uranium complex to chiral pesticides R/S‐malaoxons

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Unraveling complexation and enantioseparation of a new chiral-at-uranium complex to chiral pesticides R/S-malaoxons

A novel chiral-at-uranium complex (Uranyl-HPIDO) was designed for enantioseparation of R/S-malaoxons (R/S-MLXs). Based on density functional theory, we unraveled complexation between Uranyl-HPIDO and R/S-MLXs. The results indicated that Uranyl-HPIDO preferred to bind to phosphoryl oxygen of R/S-MLXs to form stable complexes and realized the enantioseparation of chiral MLXs.


Unraveling uranium complexes has become a popular study topic in recent years to address the problem of spent fuel treatment. An important and promising investigation is the enantiomer separation of chiral organophosphorus pesticides (OPs) via uranyl-containing receptors. Among them, malaoxon (MLX), as a chiral OP with high toxicity and good selectivity, is controversial because of the different toxicity differences caused by the R and S configurations to target and non-target organisms. Therefore, it is crucial to explore effective methods for separating its enantiomers. In this work, a novel 2-(9-[1H-pyrazole-1-carbonyl]-1,10-phenanthrolin-2-yl)-1H-inden-1-one (HPIDO) ligand, which combines with uranyl to form the chiral-at-uranium complex (Uranyl-HPIDO receptor), was designed for the enantioseparation of R/S-malaoxons (R/S-MLXs). Based on density functional theory (DFT), we explored the potential coordination modes between the Uranyl-HPIDO receptor and R/S-MLXs at various sites. The analyses of bonding properties, orbital interactions, and weak interactions of intramolecular groups of the complexes, along with the study of thermodynamic properties, revealed that the Uranyl-HPIDO receptor preferred to bind to the phosphoryl oxygen (O5) of R/S-MLXs to form stable complexes. Good enantioseparations of the two enantiomers were achieved in various solvents (water, n-Butanol, n-Octanol, dichloromethane, propanoic acid, toluene, and cyclohexane); the separation factors (SF R/S) ranged 21–853, and the enantioselectivity coefficients (ESC R/S) were more than 95%. The findings could theoretically offer useful information and guidance for the separation of R/S-MLXs, in addition to providing fresh concepts for the creation of novel uranyl receptors.

Solvent Effects on the Spin Crossover Properties of Manganese (III) (sal‐N‐1,5,8,12) Complexes

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Solvent Effects on the Spin Crossover Properties of Manganese (III) (sal-N-1,5,8,12) Complexes

Three new solvent adducts [Mn(sal-N-1,5,8,12)]I⋅CH3OH, [Mn(sal-N-1,5,8,12)]I⋅C2H5OH and [Mn(sal-N-1,5,8,12)]I⋅CH3CN, as well as a rare compound, [Mn(sal-N-1,5,8,12)]I3 are synthesized. Surprisingly, the solvent in compound [Mn(sal-N-1,5,8,12)]I⋅CH3OH easily escapes, and with a slight increase in temperature, the crystal collapses, eventually turning into a powdered state. The magnetic properties undergo significant changes accompanying the loss of the solvent.


Abstract

The interplay of host-guest interactions and controlled modulation of spin-crossover (SCO) behavior is one of the most exploited topics regarding data storage, molecular sensing, and optical technologies. This study examines the effect of solvents on the spin-crossover (SCO) behavior of manganese(III) complexes [Mn(sal-N-1,5,8,12)]I•S (S=CH3OH, C2H5OH, CH3CN) (1) and [Mn(sal-N-1,5,8,12)]I3 (2), where (sal-N-1,5,8,12)2− is 2,2′-((1E,13E)-2,6,9,13-tetraazatetradeca-1,13-diene-1,14-diyl)diphenol synthesized by salicylaldehyde and 1,2-bis(3-aminopropylamino)ethane. The complexes, crystallizing in orthorhombic or monoclinic systems, exhibit similar supramolecular arrangements with one-dimensional cationic chains at low temperatures. Magnetic studies reveal that solvent inclusion sharpens the SCO transition and lowers the transition temperature. Specifically, 1⋅CH3OH shows a 13 K thermal hysteresis due to methanol‘s mobility through the channels in the cationic framework. Although the solvent-free compound was not obtained, compound 2 with a linear I3 − anion was synthesized, displaying extensive cation-anion contacts and a distinct 13 K thermal hysteresis upon heating due to altered intermolecular cooperativity. This emphasizes the significant role of solvent introduction and variation in crystal packing and their impact on the SCO properties.

Ring Opening Copolymerization of Epoxides with CO2 and Organic Anhydrides Promoted by Dinuclear [OSSO]‐type Metal Complexes

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The ternary copolymerization of a series of cyclic anhydrides with epoxides and carbon dioxide using dinuclear [OSSO]-type chromium (III),1, and -iron(III), 2, complexes (0.1 mol%) in combination with (bis(triphenylphosphine)iminium chloride) (PPNCl, 0.5-1.0 mol with respect to catalyst) as co-catalyst is reported in this study. The results have yielded copolymers with polyester and polycarbonate segments with high molecular weights and narrow dispersity. The catalytic systems 1-2/PPNCl were tested in the copolymerization of different epoxides, such as propylene oxide (PO), cyclohexene oxide (CHO), and vinylcyclohexene oxide (VCHO), with a variety of cyclic anhydrides, such as phthalic (PA), diglycolic (DGA) and succinic (SA), with CO2 pressure of 20 bar, temperature range of 45-80 °C in 24 h. Anhydride reaction, affording the polyester segments, exceeded the conversion of 99% in all the explored cases. On the other hand, in the case of epoxide copolymerization with CO2, for the propylene oxide (PO) reaction, the selectivity towards polypropylene carbonate (PPC) without polyether linkage consistently was >99%. For the terpolymerization of PO, CO2 and diglycolic anhydride (DGA), a notable epoxide conversion of 86%, selectively to polycarbonate, with TOF value as high as 36 h-1, was achieved.

Photoelectrocatalytic Conversion of Nitrates to Ammonia: Effect of Proton Donor

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Changes in farming techniques have facilitated the movement of nitrogen-containing species, making converting nitrate into ammonia (fertilizer) highly desirable. Recently, we introduced a photosystem comprising NiO/Au plasmon/TiO2 that can selectively convert nitrate to ammonia at neutral pH and room temperature using visible light in a photo-electrochemical approach. The study evaluated the role of adding alcohol to the overall process activity and selectivity. Adding small quantities of alcohol to the electrolyte leads to changes in the catalytic behaviour, which cannot be attributed exclusively to improvement in counter-electrode reaction kinetics. Analysis of product Faradaic efficiency and photo-current measurements revealed that alcohols act as proton donors in nitrate/nitrite reduction, possibly through a concerted proton-couple electron transfer mechanism. These initial findings offer new handles for nitrate reduction to ammonia efficacy at neutral pH. Ultimately, this opens up avenues for agricultural practices that recycle nutrients, improve process circularity, and reduce fertilizer costs, thus contributing to economic sustainability.