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The emergence of accelerated aging reaction provided a safer, cleaner, and more sustainable technology for material manufacturing and biomass treatment but still underexploited in organic synthesis and medicinal chemistry. We report the first mechanochemical accelerated aging strategy for solvent-minimal (cascade) cross dehydrogenative coupling (CDC) reactions between glycine esters/amides and a range of nucleophiles, which features clean and convenient setup, ambient temperature, atmospheric oxidation, and feasibility, for multigram-scale synthesis. By virtue of these facts, the present method provided an expedient and sustainable alternative to synthesize biologically important α-glycine derivatives and functionalized 1,4-dihydropyridines including the precursor of the antioxidant AV-154 and calcium channel blocker analogs. Mechanistically, a pre-grinding of the reactants and silica gel/NaCl facilitated spontaneous oxidation of glycine esters/amides under open air without continuous energy input followed by a coupling reaction (and sequential transformations). Multiform green metrics calculation demonstrates that the current accelerated aging protocol meets many of the principles of green chemistry such as waste prevention, high atom economy, unnecessary solvent, and good energy efficiency. [ABSTRACT FROM AUTHOR]

The fabrication of type II heterojunctions is an efficient strategy to facilitate charge separation in photocatalysis. Here, mixed dimensional 0D/2D van der Waals (vdW) heterostructures (graphene quantum dots (GQDs)–MoS2) for generating hydrogen from water splitting are investigated based on density functional theory (DFT). The electronic and photocatalytic properties of three heterostructures, namely, C6H6–MoS2, C24H12–MoS2 and C32H14–MoS2 are estimated by analyzing the density of states, charge density difference, work function, Bader charge, absorption spectra and band alignment. The results indicated that the built-in electric fields from GQDs to MoS2 boost charge separation. Meanwhile, all the GQDs–MoS2 exhibit strong absorption in the visible light region. Surprisingly, the transition of heterojunctions from type I to type II is realized by tuning the size of GQDs. In particular, C32H14–MoS2 with enhanced visible-light absorption and an appropriate band edge position, as a type II heterostructure, may be a promising photocatalyst for generating hydrogen from water splitting. Thus, in this work a novel type II 0D/2D nanocomposite as a photocatalyst is constructed that provides a strategy to regulate the type of heterostructure from the perspective of theoretical calculation. [ABSTRACT FROM AUTHOR]

Optical nonlinearity of two-dimensional (2D) materials with a permanent dipole is a subject of intense research in the fields ranging from all-optical signal processing to laser nanotechnology due to the potential outstanding performance of 2D materials in nonlinear optical processes, and the feasibility for extensive integration into optoelectronic devices. In the present work, the group-VA binary monolayers are predicted to have giant and broadband second harmonic generation (SHG) properties superior to some of the most popular NLO materials by first-principles calculations. The SHG susceptibility of the α-PAs reaches up to 8.0 × 106 pm2 V−1, which is nearly 1–2 orders of magnitude higher than that of honeycomb monolayer MoS2 and h-BN, and twice larger than the record-high SHG susceptibility of a 2D ferroelectric GeSe monolayer. This intriguing peak is formed by intraband two photon transition ascribed to the relatively small bandgap and large transition matrix elements between valence and conduction band edges. A high-performance nonlinear optical device can be developed using those 2D group-VA monolayer materials with puckled structure and in-plane polarizabilities for multifunctional and integrated optoelectronic applications. [ABSTRACT FROM AUTHOR]

Using the density functional theory (DFT) calculations, we find that  Janus group-III chalcogenide monolayers can serve as a suitable substrate for silicene, and the Dirac electron band properties of silicene are also fully preserved. The maximum opened band gap can reach 179 meV at the Dirac point due to the interaction of silicene and the polar two-dimensional (2D) substrate. In addition, the electronic band structure of the heterostructure can be modulated by applying an electric field where its predicted band gap increases or decreases according to the direction of the applied external electric field. Furthermore, an insight into the electron structures can be understood by analyzing the electron energy-loss (EEL) spectra. From these results, we also predict that heterostructures with polar 2D substrates have broad application prospects in multi-functional devices. Besides, Janus group-III chalcogenide monolayers can be used as good substrates for growing silicene and the modulation of the electronic structure can also be applied to nanodevices and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Two-photon photodynamic therapy (TP-PDT) plays crucial roles in curing tumors because it involves deep penetration of drugs into the tissue and has minimal damage to the surrounding cells. Our theoretical study was aimed at providing fresh insights into photosensitizers, such as [Ir(N^C)2(N^N)]+ (N^C = 2-phenylpyridine, N^N = bis-benzimidazole) and [Rh(N^C)2(N^N)]+, to treat cancer via the TP-PDT route. To better understand the properties of the complexes [Ir(N^C)2(N^N)]+ and [Rh(N^C)2(N^N)]+, the one-photon and two-photon absorption electronic spectra, energy gap (ΔES–T), strength of two-photon absorption cross-section (δ), spin–orbit matrix element (〈S1☋ĤSO☋Tj〉), and phosphorescence lifetimes (τ) were calculated by DFT and TD-DFT. The calculation results suggested that both complexes met the criteria (i.e. an efficient ISC process, enough energy to produce 1O2 and phototherapeutic window of the absorption wavelength) of photosensitizers; importantly, the designed complex [Rh(N^C)2(N^N)]+ had better performance than [Ir(N^C)2(N^N)]+, especially in the long-lived triplet excited state. It is expected that our research can make quite a few contributions to the development of photosensitizers and establish some guidelines for experiments based on TP-PDT. [ABSTRACT FROM AUTHOR]

In the present work, the structural, magnetic and electronic properties of a novel one-dimensional infinite monatomic copper wire (1D-IMCW) have been investigated using first-principles computational calculation. Geometrical optimization shows that a minor difference in energy will lead to a transformation happening between a non-magnetic configuration and a magnetic configuration with the condition of a weak magnetic field. Notably, ferromagnetic 1D-IMCW can be used as a half-metal according to the calculated results of its band structure and density of states. Furthermore, it is discovered that this nanowire exhibits excellent optical properties, i.e. strong absorption across the visible range. [ABSTRACT FROM AUTHOR]

Solvent recovery is a big challenge in conventional solution electrospinning for the large-scale production of ultrafine fibers because the precursor utilization ratio is usually less than 20 wt%. In this paper, we report an eco-friendly two-component electrospinning technique for the fabrication of acrylate composite fibers using a homemade device at room temperature. During this electrospinning process, the two-component spinning solutions (component A: t-butyl peroxy-2-ethyl hexanoate (BPOEH), isobornyl methacrylate (IBOMA), nitrile rubber (NBR), methacrylic acid (MAA); component B: N,N-dimethylaniline (DMA), IBOMA, NBR and MAA) are nearly all electrospun into ultrafine fibers, and the utilization ratio of the precursor can reach more than 90 wt%. The fiber solidification mechanism can be ascribed to the rapid polymerization of the IBOMA monomer in the presence of free radicals formed by a redox initiation system (BPOEH + DMA), which is different from the solvent evaporation in solution electrospinning or cooling solidification in melt electrospinning. Such a two-component electrospinning technique may stimulate the development of an eco-friendly approach to fabricate composite and functional ultrafine fibers. [ABSTRACT FROM AUTHOR]

Two-photon photodynamic therapy (TP-PDT) is a very promising treatment that has drawn much attention in recent years due to its ability to penetrate deeper into tissues and minimize the damage to normal cells. Here, the properties of three highly water soluble Ru(ii) and Zn(ii) polypyridyl complexes as photosensitizers (PSs) were examined, including the one-photon and two-photon absorption (OPA and TPA) spectra, singlet–triplet energy gap (ΔH–L), TPA cross-section and spin–orbit coupling constant via Density Function Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT). Their potential therapeutic use as photosensitizers in TP-PDT is proposed, where the reasoning is as follows: first, they possess strong absorption in the therapeutic window; second, the vertical excitation energy is greater than 0.98 eV, which can generate a singlet oxygen species and the remarkable coupling between the S1 and T1 states. Moreover, the spin–orbit matrix elements are greater than 0.24 cm−1 for Ru-bpy and Zn-tpy, indicating that the intersystem spin crossing processes are efficient. It is expected that these complexes will be applied to PSs in TP-PDT, and we hope this research can serve as a guideline for the development of efficient two-photon PSs. [ABSTRACT FROM AUTHOR]

Vesicles are well-sealed capsules that can store or transport substances. Their dynamic evolution mechanisms are important to fulfill specific functions. In the present study, dissipative particle dynamics (DPD) simulation was employed to study the formation, fusion, and fission pathways of vesicles. Our results show that comb-like block copolymer-tethered nanoparticles can self-assemble into stable vesicles, which may be a good candidate for drug entrapment and controlled release of drug. The spontaneous fusion of this type of vesicles has been studied, whose mechanism is different from that of the vesicles formed from comb-like block copolymers. However, the fission mechanisms of the two types of vesicles are similar. To summarize, the introduction of nanoparticles alters the fusion mechanism, but causes no difference in the fission pathway of vesicles. The reason may be attributed to the nature of nanoparticles. The fusion and fission processes always experience the congregation of nanoparticles. The large and rigid nanoparticles inevitably result in changes of surface tension of the vesicle that is a key factor influencing the membrane dynamics. [ABSTRACT FROM AUTHOR]

To overcome tough conditions currently used for the preparation of nanostructured hematite films on a conducting substrate, a rational and easy method of chemical etching involving Fe3+ release and material growth in the presence of OH− has been developed. By carefully tuning the parameters influencing the morphologies of hematite, including the synthetic procedure, the concentration of etching solution, temperature, etching time and the morphology controlling surfactant, hematite films grown on iron foil with various morphologies (e.g. nanorod, nanowire, ultrathin nanoflake and cauliflower-like shape) have been achieved. In particular, it is found that F− is an effective surfactant to control the morphology as well as the crystallization process of hematite. Ultrathin nanoflakes having a minimized feature size exhibit the best photocurrent of 0.5 mA cm−2 (1.23 V vs. RHE, RHE is reversible hydrogen electrode) among the samples tested as a result of facilitated hole diffusion to the electrolyte and thus lowered carrier recombination. Compared with pristine hematite, a nearly tripled photocurrent is observed when H2O2 is added in the electrolyte as a hole scavenger, suggesting the presence of a charge injection barrier in the surface of samples. According to this, the strategy of Co2+ treatment is utilized and the improved photocurrent is seen, likely due to the improved water oxidation kinetics and surface state passivation. We believe that this convenient and economical method can be extended to the synthesis of other alkaline metal oxide nanomaterials as long as the redox potential of S2O82−/SO42− is higher than Mn+/M (M refers to metal). [ABSTRACT FROM AUTHOR]

Free-standing graphene-based macroscopic membranes, which are characterized by a layered structure and tunable conductivity, are prepared by a self-assembly process at a liquid–air interface. Since the preliminary results indicate that it is hard to construct macroscopic graphene membranes solely by low-temperature exfoliated graphene nanosheets (LGNs) at the liquid–air interface, graphene oxide nanosheets (GONs), as the stacking template and sticking component, are introduced into the assembly process of graphene layers to promote the formation of layer-by-layer stacking structure and help form a conductive macroscopic membrane. The conductivity of such a graphene-based membrane can be tuned by changing the GON fraction in the LGN/GON hybrid membrane. [ABSTRACT FROM AUTHOR]

The influence of the nature of metal ions and reaction conditions on the formation of group IIB metal coordination architectures of a tetrazole ligand, 2-(1H-tetrazol-5-yl)pyrazine (HL), and the luminescent properties of some complexes have been investigated. At room temperature, the reactions of Zn(NO3)2∙6H2O (or ZnCl2) and Cd(NO3)2∙6H2O with HL gave rise to two reported complexes, [M(L)2(H2O)2] (1 and 2, Acta Crystallogr., Sect. C, 2006, 62, m614; Acta Crystallogr., Sect. E, 2006, 62, m2841), respectively. However, under hydrothermal conditions, the same reactions yield 1 and another complex, {[Cd2(L)4](H2O)0.25}n (3), respectively. In both preparation conditions mentioned above, the HL ligand reacts with Hg(OAc)2 (or HgBr2) to give complexes, [Hg(L)2]n (4), [Hg(L)2]n (5) and [Hg(L)Br]n (6) with different structures. 1 and 2 have a similar mononuclear structure and in the crystal structure such molecules are further assembled together to form a 3-D α-Pt topological framework with O–H⋯N hydrogen bonds. 4 possesses a 1-D chain structure, in which the Cd(ii) center is six-coordinated, with all coordination sites being occupied by N atoms of the ligands. Furthermore, such chains are interlinked viaπ⋯π interactions to form a 3-D framework. 4 has a 2-D (6,3) topological structure, in which the Hg(ii) center is six-coordinated to six N atoms of L, and the L ligand takes a chelating-bridging mode similar to that in 3. 5 has a 2-D (4,4) topological layer structure with the metal center being six-coordinated, and the six coordination sites are held by N atoms from four L ligands, taking different coordination modes. Moreover, such planes are generated to form a 3-D structure via two kinds of π⋯π interactions. 6 is a 2-D layer with the Hg(ii) coordinating to a Br atom and three N atoms of three tetrazole rings from different L ligands. This result shows that the metal ions and reaction conditions have significant influence on the group IIB metal complexes of this multifunctional ligand, and the intramolecular/intermolecular weak interactions are likely to play important roles in the formation of such complexes, especially linking the discrete subunits or low-dimensional entities into high-dimensional frameworks. In addition, the luminescent studies of HL and 1, 2, 3 and 6 indicate that they display blue emissions with different densities in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

An azido–metal–1,2,4-triazolate coordination polymer, [Cu(trz)(N3)]n (trz = 1,2,4-triazolate) was synthesized using hydrothermal methods; the complex has a rare three-dimensional non-interpenetrated utp or (10,3)-d topological network structure and exhibits spin-canted antiferromagnetism at low temperature. [ABSTRACT FROM AUTHOR]

The in situ solvothermal reaction of 3,4-dicyano-1,2,5-thiadiazole with MCl2 (M = Co, Ni) and NaOH afforded two isomorphous complexes, [M2(L)2(H2O)2]n (L = 2,1,3-thiadiazole-4,5-dicarboxylate), which exhibit a rare non-interpenetrated (10,3)-d (utp) network topology and interesting magnetic behaviors: spin-canted antiferromagnetism for the CoII complex, but simple antiferromagnetic coupling for the NiII. [ABSTRACT FROM AUTHOR]

The in situ solvothermal reaction of 9,10-dicyanoanthracene and ZnCl2/NaN3 gave the complex, {[Zn7(OH)8(DTA)3]·H2O}n (1) (DTA2− = 9,10-ditetrazolateanthracene), which presents a pcu-type topological framework formed by DTA2− bridging unprecedented heptanuclear spindle [Zn7(OH)8]6+ clusters as SBUs, and exhibits strong luminescent emission with long lifetime. [ABSTRACT FROM AUTHOR]

Disulfiram (DSF) can target and kill cancer cells by disrupting cellular degradation of extruded proteins and has therefore received particular attention for its tumor chemotherapeutic potential. However, the uncontrollable Cu 2+ /DSF ratio reduces the efficacy of DSF-mediated chemotherapy. Herein, self-supplying Cu 2+ and oxidative stress synergistically enhanced DSF-mediated chemotherapy is proposed for melanoma-based on PVP-coated CuO 2 nanodots (CPNDs). Once ingested, DSF is broken down to diethyldithiocarbamate (DTC), which is delivered into a tumor via the circulation. Under the acidic tumor microenvironment, CPNDs produce sufficient Cu 2+ and H 2 O 2 . DTC readily chelates Cu 2+ ions to generate CuET, which shows antitumor efficacy. CuET-mediated chemotherapy can be enhanced by H 2 O 2 . Sufficient Cu 2+ generation can guarantee the maximum efficacy of DSF-mediated chemotherapy. Furthermore, released Cu 2+ can be reduced to Cu + by glutathione (GSH) and O 2- in tumor cells, and Cu + can react with H 2 O 2 to generate toxic hydroxyl radicals (·OH) via a Fenton-like reaction, promoting the efficacy of CuET. Therefore, this study hypothesizes that employing CPNDs instead of Cu 2+ ions could enhance DSF-mediated melanoma chemotherapy, providing a simple but efficient strategy for achieving chemotherapeutic efficacy., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The fabrication of type II heterojunctions is an efficient strategy to facilitate charge separation in photocatalysis. Here, mixed dimensional 0D/2D van der Waals (vdW) heterostructures (graphene quantum dots (GQDs)-MoS 2 ) for generating hydrogen from water splitting are investigated based on density functional theory (DFT). The electronic and photocatalytic properties of three heterostructures, namely, C 6 H 6 -MoS 2 , C 24 H 12 -MoS 2 and C 32 H 14 -MoS 2 are estimated by analyzing the density of states, charge density difference, work function, Bader charge, absorption spectra and band alignment. The results indicated that the built-in electric fields from GQDs to MoS 2 boost charge separation. Meanwhile, all the GQDs-MoS 2 exhibit strong absorption in the visible light region. Surprisingly, the transition of heterojunctions from type I to type II is realized by tuning the size of GQDs. In particular, C 32 H 14 -MoS 2 with enhanced visible-light absorption and an appropriate band edge position, as a type II heterostructure, may be a promising photocatalyst for generating hydrogen from water splitting. Thus, in this work a novel type II 0D/2D nanocomposite as a photocatalyst is constructed that provides a strategy to regulate the type of heterostructure from the perspective of theoretical calculation.

To overcome tough conditions currently used for the preparation of nanostructured hematite films on a conducting substrate, a rational and easy method of chemical etching involving Fe 3+ release and material growth in the presence of OH - has been developed. By carefully tuning the parameters influencing the morphologies of hematite, including the synthetic procedure, the concentration of etching solution, temperature, etching time and the morphology controlling surfactant, hematite films grown on iron foil with various morphologies (e.g. nanorod, nanowire, ultrathin nanoflake and cauliflower-like shape) have been achieved. In particular, it is found that F - is an effective surfactant to control the morphology as well as the crystallization process of hematite. Ultrathin nanoflakes having a minimized feature size exhibit the best photocurrent of 0.5 mA cm -2 (1.23 V vs. RHE, RHE is reversible hydrogen electrode) among the samples tested as a result of facilitated hole diffusion to the electrolyte and thus lowered carrier recombination. Compared with pristine hematite, a nearly tripled photocurrent is observed when H 2 O 2 is added in the electrolyte as a hole scavenger, suggesting the presence of a charge injection barrier in the surface of samples. According to this, the strategy of Co 2+ treatment is utilized and the improved photocurrent is seen, likely due to the improved water oxidation kinetics and surface state passivation. We believe that this convenient and economical method can be extended to the synthesis of other alkaline metal oxide nanomaterials as long as the redox potential of S 2 O 8 2- /SO 4 2- is higher than M n+ /M (M refers to metal).