Design, preparation and pharmacodynamics of ICG-Fe(Ⅲ) based HCPT nanocrystals against cancer

The use of nanocrystal technology to manufacture drug delivery systems intended to enhance therapeutic efficacy has attracted the attention of the pharmaceutical industry.However,the clinical application of nanocrystal drugs for injection is restricted by Ostwald ripening and the large-scale use of stabilizers such as polysorbate and lecithin,which have potential toxicity risks including hemolysis and allergies.Here,we designed an amorphous nanocrystal drug complex(IHNC),which is stabilizer-free and composed of indocyanine green(ICG)framework loading with a chemotherapeutic agent of 10-hydroxycamptothecin(HCPT).Considering the possibility of industrial manufacturing,IHNC was simply prepared with the assistance of ferric ion(III)via supramolecular assembly strategy.The theoretical result of Materials Studio simulation indicated that the prepared ICG-Fe(III)framework showed a stable spherical structure with the appropriate cavity for encapsulating the two drugs of HCPT and ICG with equal mass ratio.The IHNC was stable at physiological pH,with excellent PTT/PDT efficacy,and in vivo probing characteristics.The nanoscale size and reductive stimuli-responsiveness can be conducive to drug accumulation into the tumor site and rapid unloading of cargo.Moreover,such combination therapy showed synergistic photo/chemotherapy effect against 4T1 breast cancer and its tumor inhibition rate even up to 79.4%.These findings demonstrated that the nanocrystal drug delivery strategy could avoid the use of stabilizers and provide a new strategy for drug delivery for combination therapy.

Side-Chain Engineering of Non-Fullerene Acceptors with Trialkylsilyloxy Groups for Enhanced Photovoltaic Performancet

Side-chain engineering has emerged as a highly effective strategy for tailoring the aggregation behavior and charge transport properties of non-fullerene small molecule acceptors(SMAs).In this study,we designed and synthesized two SMAs,namely BTPSi-Bu and BTPSi-Pr,respectively incorporating tributylsilyloxy and trisopropylsilyloxy groups in their outer positions.Notably,BTPSi-Bu exhibited better planarity,crystallization,and favorable phase separation when paired with PM6 donor polymer compared to its counterpart,BTPSi-Pr.The resulting organic solar cells,utilizing the PM6:BTPSi-Bu blend,demonstrated a remarkable power conversion efficiency of 17.41%and a high open-circuit voltage of 0.859 V.These findings underscore the significance of integrating trialkylsilyloxy side chains into SMAs as a rational design approach for enhancing the performance of photovoltaic systems.

Single atom doping induced charge-specific distribution of Cu1-TiO_(2) for selective aniline oxidation via a new mechanism

Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile,identifying the active site also represents a significant obstacle,primarily due to the intricate electronic environment of single atom site doped metal oxide.Herein,a single atom Cu doped TiO_(2)catalyst(Cu_(1)-TiO_(2)) is prepared via a simple“colloid-acid treatment”strategy,which switches aniline oxidation selectivity of TiO_(2) from azoxybenzene to nitrosobenzene,without using additives or changing solvent,while other metal or nonmetal doped TiO_(2) did not possess.Comprehensive mechanistic investigations and DFT calculations unveil that Ti-O active site is responsible for triggering the aniline to form a new PhNOH intermediate,two PhNOH condense to azoxybenzene over TiO_(2) catalyst.As for Cu_(1)-TiO_(2),the charge-specific distribution between the isolated Cu and TiO_(2) generates unique Cu_(1)-O-Ti hybridization structure with nine catalytic active sites,eight of them make PhNOH take place spontaneous dissociation to produce nitrosobenzene.This work not only unveils a new mechanistic pathway featuring the PhNOH intermediate in aniline oxidation for the first time but also presents a novel approach for constructing single-atom doped metal oxides and exploring their intricate active sites.

Metal-Free C_(3)N_(4) with plentiful nitrogen vacancy and increased specific surface area for electrocatalytic nitrogen reduction

As a substitute for synthetic ammonia under mild condition, electrocatalytic nitrogen reduction reaction(NRR) provides a hopeful approach for the development of ammonia. Nevertheless, the current development of NRR electrocatalysts is far from enough and a systematic research is needed to gain a better improvement. This article presents that 2 D C_(3)N_(4)-NV with a large specific surface area and abundant nitrogen vacancies is prepared by a simple and feasible method, and used as a metal-free catalyst for electrocatalytic NRR. Experiment result and density functional theory(DFT) calculation reveal that nitrogen vacancies in 2 D C_(3)N_(4)-NV can act as an efficient active site for catalytic NRR, which is conducive to capturing and activating N_(2), lowering Gibbs free energy(DG) in reaction and inhibiting hydrogen evolution reaction(HER) at the same time. In addition, the larger specific surface area also makes more active site exposed, which is good for the contact between the electrolyte and the active site, thus enhancing its NRR activity. The electrocatalyst shows an excellent catalytic activity for NRR in 0.1 M HCl, including Faradaic efficiency of 10.96%, NH_(3) yields of 17.85 lg h^(-1) mg_(cat)^(-1)., and good stability(over 20 h).

Reductive Deoxygenative Functionalization of Alcohols by First-Row Transition Metal Catalysis

Alcohols are among the most accessible functionalities.Catalytic deoxygenative functionalization of alcohols is highly synthetically appealing.While significant progress has been made on the reactions with nucleophiles,the reactions with electrophilic coupling partners remain a real challenge.This manuscript highlights the advance in this direction,which is mainly achieved by the first-row transition metals.The low-valent titanium catalyst has shown the unique reactivity to homolytically cleave the C—OH bonds.The formed carbon radicals could either undergo reduction to give protonation products or couple with carbon fragments to form C—C bonds.This chemistry is initially realized using a stoichiometric amount of titanium reagents and later extended to catalytic variants.Nickel features a variety of oxidation states ranging from Ni0 to NiIV,and both two-electron oxidative addition and single-electron process are involved in their activation of an electrophile.These properties enable nickel to catalyze reductive C—C coupling of alcohols with R–X electrophiles.The reaction is first reported on the reactions of allylic alcohols,then extended to benzylic alcohols and,very recently non-activated alcohols.Recent effort has resulted in many invaluable methodologies that highly improve the reaction efficiency for the construction of aliphatic C—C bonds.The use of cobalt and copper catalysts not only expands the substrate scope of these reactions but also shows the new reactivity and selectivity issues.

N-Aryl diketopyrrolopyrrole derivatives towards organic optical and electronic materials

Diketopyrrolopyrrole(DPP)and related derivatives have drawn great attention due to their applications in organic optical/electronic materials.Progress in these materials is associated with developments in the syntheses of the DPP family.Chemical modification of DPP at nitrogen atom,including N-alkylation and N-arylation,is an effective strategy to improve its physical and chemical properties,such as solubility,optical and semiconducting properties.However,N-arylation of DPPs remains challenging compared to the easily accessible N-alkylation.Herein,the synthesis of N-aryl DPP derivatives and correlatedπ-expanded DPPs are summarized,and their optical/electronic properties are introduced.The future perspectives of N-aryl DPP derivatives are also discussed.

Nickel-catalyzed cross-electrophile C–Ge coupling of benzyl pivalates and chlorogermanes

The C–Ge cross-coupling offers a promising approach for the precise synthesis of organogermanes. However, the current methods are primarily effective in the germylation of organo(pseudo)halides. This work demonstrates the possibility of transferring low-cost and easily available ester groups into organogermanes through the cleavage of stable C–O bonds. Primary,secondary, and even tertiary benzylic pivalates were coupled well with chlorogermanes. The reactions proceed under mild conditions. The scalability of this reaction and derivatization of the formed benzylgermanes are demonstrated.

Azulene-based organic functional molecules for optoelectronics

Design and synthesis of new organic functional materials with improved performance or novel properties are of great importance in the field of optoelectronics.Azulene,as a non-alternant aromatic hydrocarbon,has attracted rising attention in the last few years.Different from most common aromatic hydrocarbons,azulene has unique characteristics,including large dipole moment,small gap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO）.However,the design and synthesis of azulene-based functional materials are still facing several challenges.This review focuses on the recent development of organic functional materials employing azulene unit.The synthesis of various functionalized azulene derivatives is summarized and their applications in optoelectronics are discussed,with particular attention to the fields including nonlinear optics（NLO）,organic field-effect transistors（OFETs）,solar cells,and molecular devices.

Mn-mediated reductive C(sp3)–Si coupling of activated secondary alkyl bromides with chlorosilanes

The construction of secondary alkylsilanes is a challenging subject in the synthetic community.The cross-coupling provides a practical solution to address this problem,but it typically relies on organometallic species.Herein,we report an Mn-mediated reductive C(sp^(3))-Si coupling to synthesize these compounds from alkyl and silyl electrophiles.This approach avoids the requirement for activation of Si-Cl by transition metals and thus allows for the coupling of various common chlorosilanes.The reaction proceeds under mild conditions and shows good functional group compatibility.The method offers access toα-silylated organophosphorus and sulfones with a scope that is complementary to those obtained from the established methods.

Covalent carbene modification of 2D black phosphorus

Black phosphorus(BP)has attracted an ever-growing interest due to its unique anisotropic two-dimensional structure,impressive photoelectronic properties and attractive application potential.However,the tools for bandgap engineering and passivation via covalent modification of BP nanosheets remain limited to diazonium salt and nucleophilic addition methods,so that developing new modification strategies for BP nanosheets is crucial to explore its physical and chemical properties and enrich the toolbox for functionalization.Herein,we report the covalent modification of liquid-phase exfoliated BP nanosheets based on a rational analysis of BP structure.The modification of BP is achieved via carbene,a highly reactive organic mediate.The carbene modification improves the solubility and stability of BP nanosheets.Detailed microscopic and spectroscopic characterizations including infrared spectra,Raman spectra,X-ray photoelectron spectra,SEM and TEM were conducted to provide insights for the reaction.The proof of the existence of covalent bonds between BP nanosheets and organic moieties confirms the successful modification.Moreover,theoretical calculations were conducted to unveil the reaction mechanism of the two different types of bonds and the chemical property of two-dimensional BP.

Synthesis and Characterization of Planar Five-Ring-Fused Dithiophene-dione

A series of new organic semiconductors based on s-indaceno[1,2-b：5,6-b＇]dithiophene-4,9-dione was success fully synthesized and characterized. The electron withdrawing carbonyl group lowers the LUMO energy levels, leading to increased electronegativities, which is beneficial for high photo-stability in air. The n-alkyl substituted compounds, lc and ld, crystallize with the rigid coplanar systems packed into slipped face-to-face n-stacks. Inter- estingly, lc and ld also show liquid crystalline behaviors, which give highly ordered molecular packing over large area.

High performance nonvolatile organic field-effect transistor memory devices based on pyrene diimide derivative

Developing high-quality electret layer is important for the fabrication of highperformance nonvolatile organic field effect transistor memory devices(OFETNVMs).In this work,three representative aromatic diimide frameworks are employed for comparative studies as n-type doping materials for the electret layers in OFET-NVMs,which are naphthalene diimide(NDI),perylene diimide(PDI),and pyrene diimide(PyDI).When blended with polystyrene(PS)to prepare the electret layers,all the memory devices containing aromatic diimide dopants exhibited significantly improved performances compared with the undoped counterparts,indicating that low-lying LUMO energy levels of these dopants are beneficial for charge injection.All the devices with n-type dopants exhibited long retention times(more than 104 s)and good switching reliability in more than 400 continuous write-read-erase-read cycles.Among them,the PyDI-based memory device exhibited superior performance compared with other aromatic diimides,which achieved a memory window of 34.0 V,a trapping charge density of 1.98×1012 cm−2 along with an on/off ratio higher than 104.This work indicates that PyDI framework could be a new platform for the future design of n-type dopant for high-performance nonvolatile organic field-effect transistor memory devices.

Intermolecular coupling enhanced thermopower in single-molecule diketopyrrolopyrrole junctions

Sorting out organic molecules with high thermopower is essential for understanding molecular thermoelectrics.The intermolecular coupling offers a unique chance to enhance the thermopower by tuning the bandgap structure of molecular devices,but the investigation of intermolecular coupling in bulk materials remains challenging.Herein,we investigated the thermopower of diketopyrrolopyrrole(DPP)cored single-molecule junctions with different coupling strengths by varying the packing density of the self-assembled monolayers(SAM)using a customized scanning tunneling microscope break junction(STM-BJ)technique.We found that the thermopower of DPP molecules could be enhanced up to one order of magnitude with increasing packing density,suggesting that the thermopower increases with larger neighboring intermolecular interactions.The combined density functional theory(DFT)calculations revealed that the closely-packed configuration brings stronger intermolecular coupling and then reduces the highest occupied molecular orbital(HOMO)-lowest unoccupied molecular orbital(LUMO)gap,leading to an enhanced thermopower.Our findings offer a new strategy for developing organic thermoelectric devices with high thermopower.

Fluoro-substituted DPP-bisthiophene conjugated polymer with azides in the side chains as ambipolar semiconductor and photoresist

Photoresists are essential for the fabrication of flexible electronics through all-photolithographic processes.Single component semiconducting photoresist exhibits both semiconducting and photo-patterning properties,and as a result,the device fabrication process can be simplified.However,the design of semiconducting polymeric photoresist with ambipolar semiconducting property remains challenging.In this paper,we report a single component semiconducting photoresist(PFDPPF4T-N_(3))by incorporating azide groups and noncovalent conformation locks into the side alkyl chains and conjugated backbones of a diketopyrrolopyrrole-based conjugated polymer,respectively.The results reveal that PFDPP4FT-N_(3) exhibits ambipolar semiconducting property with hole and electron mobilities up to 1.12 and 1.17 cm^(2) V^(−1) s^(−1),respectively.Moreover,field effect transistors with the individual photo-patterned thin films of PFDPP4FT-N_(3) also show ambipolar semiconducting behavior with hole and electron mobilities up to 0.66 and 0.80 cm^(2) V^(−1) s^(−1),respectively.These results offer a simple yet effective design strategy for high-performance single component semiconducting photoresists,which hold great potential for flexible electronics processed by all-photolithography.

Nickel-Catalyzed Cross-Electrophile Vinyl–Vinyl Coupling:An Approach to Structurally Versatile Dienylboronates

Cross C–C bond formation of two vinyl electrophiles is a long-standing challenge in synthetic chemistry.Herein,we report a nickel-catalyzed reductive vinyl–vinyl coupling between vinyl triflates and boron-substituted vinyl bromides.This new protocol offers facile access to dienylboronates with high structural complexity and molecular diversity.The reaction proceeds with a broad substrate scope under very mild conditions.The synthetic utility of the method is highlighted by its gram-scale reaction,modification of complex molecules,and diverse transformation of the products.