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In continuation of previously reported results, the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene-1-ium acetate was also found to be a powerful non-derivatizing solvent for cellulosic waste such as paper and cardboard. The ionic liquid could dissolve all the present bio-polymers (cellulose, hemicellulose, and lignin) in high concentrations, resulting in solutions with visco-elastic properties that were suitable for dry-jet wet fiber spinning. The cellulosic raw materials were refined gradually to identify the influence of residual components on the spinnability of the respective solution. Polymer degradation and losses in the spinning process could be avoided nearly entirely. With the exception of virtually unrefined cardboard, all the samples showed excellent spinnability, resulting in fibers with high tensile strength. Prototype textiles were produced to validate the quality of the fibers and demonstrate the possibility of using residual lignin in cardboard as a natural dye. [ABSTRACT FROM AUTHOR]

Ruthenium nitrosyl (RuNO) complexes continue to attract significant research interest due to several appealing features that make these photoactivatable nitric oxide (NO˙) donors attractive for applications in photoactivated chemotherapy. Interesting examples of molecular candidates capable of delivering cytotoxic concentrations of NO˙ in aqueous media have been discussed. Nevertheless, the question of whether most of these highly polar and relatively large molecules are efficiently incorporated by cells remains largely unanswered. In this paper, we present the synthesis and the chemical, photophysical and photochemical characterization of RuNO complexes functionalized with 17α-ethinylestradiol (EE), a semisynthetic steroidal hormone intended to act as a molecular Trojan horse for the targeted delivery of RuNO complexes. The discussion is centered around two main molecular targets, one containing EE (EE-Phtpy-RuNO) and a reference compound lacking this biological recognition fragment (Phtpy-RuNO). While both complexes displayed similar optical absorption profiles and NO˙ release efficiencies in aqueous media, important differences were found regarding their cellular uptake towards dermal fibroblasts, with EE-Phtpy-RuNO gratifyingly displaying a remarkable 10-fold increase in cellular uptake when compared to Phtpy-RuNO, thus demonstrating the potential drug-targeting capabilities of this biomimetic steroidal conjugate. [ABSTRACT FROM AUTHOR]

In view of the growing demand for synthetic molecules or materials by researchers from both the core sciences and interdisciplinary sectors, the field of organic synthesis needs to be strategically more powerful to produce more molecules in a shorter time. Ensuring a reduction in the use of solvents, catalysts, reagents, time, effort, and waste is essential during green chemical syntheses. Keeping those criteria in mind, the integration of chemical reactions is very much needed. Integrated organic synthesis can be considered the ideal replacement for stepwise synthesis to fulfill demand while maintaining green parameters. The electrochemical cascade process satisfies the essential criteria of greener integrated synthesis to a great extent, providing a modern strategic tool in the arsenal of synthetic chemists. The strategy is applied extensively by researchers, as evidenced by the growing number of publications, amounting to more than a hundred papers on the development of synthesis methods using electrochemical cascade reactions. A thorough understanding of the process is needed to implement the strategy further in targeted synthesis and methodology development for cutting-edge research. To grow the concept among researchers, a concise account of published articles on the topic, depicting the mechanisms, prospects, and problems of the developed methods, is highly desirable. Quenching the thirst herein, we present a concise review of electrochemical cascade processes reported in the literature since 2015. The precedent reactions developed earlier are also discussed in this context. Electrochemical multicomponent reactions involving the cascade process are also covered, expanding the scope of the review. The sections are classified based on the types of functionalization. The mechanistic details of each category of reactions are thoroughly covered to present a clear idea of the redox behavior of different reagents under electrochemical conditions. The prospects and problems associated with the methods are also discussed. [ABSTRACT FROM AUTHOR]

Sequential peptide coupling plays a central role in chemical protein synthesis. This paper describes a new peptide derivative, peptide-aminothiazoline (At), whereof the C-terminus is functionalized with 2-aminothiazoline. Peptide-At streamlined the sequential peptide ligation in a one-pot manner and demonstrated the convergent synthesis of a circular protein and homogeneous glycoproteins. [ABSTRACT FROM AUTHOR]

Extending the catalytic valorization roadmap of platform molecules is one of the core tasks in the development of the biomass conversion field. Through ongoing research efforts, the transformation system of biomass-derived platform molecules has been well established and is gradually becoming relatively mature. In this context, it is of great practical interest to further explore next-generation platform molecules and their valorization pathways that have recently emerged. Linear diketones, usually derived from biomass and their C6 furan compounds, are one of the novel platform molecules that have been recently spotlighted for the synthesis of high-end chemicals due to their huge valorization potential. Herein, we intend to underline the crucial platform role that linear diketones, i.e., 2,5-hexanedione (HD) and 1-hydroxy-2,5-hexanedione (HHD), play in extending the biomass valorization roadmap to a broader one. Perspectives are concentrated on elucidating the heterogeneous tandem conversion system of biomass and its derived C6 furan compounds to HD and HHD. Also, we further demonstrate the diverse valorization routes of HD and HHD to high-end chemicals for various applications. The insights presented in this paper may contribute to highlighting the bright future of linear diketones in constructing a sustainable biomass valorization system. [ABSTRACT FROM AUTHOR]

In 2011, Zhang's research team, in cooperation with Li and Liu, reported the Pt1/FeOx atomically dispersed catalysts for the first time in the world, and based on this, proposed the concept of "single-atom catalysts". Single-atom catalysts (SACs) have a wide range of industrial application prospects in the catalytic synthesis of fine chemicals due to their high atomic utilization rate and special catalytic activity. With the deepening of the research, the preparation methods of SACs emerge in an endless stream, but it is still an urgent problem to realize the industrial production of highly stable SACs prepared in small batches (gram level) or even in large batches (kilogram level). In this review paper, several typical solvent-free green synthetic strategies (e.g., ball milling, physical mixing, gas migration, and pyrolyzing coordination polymers (including MOFs)) for the batch preparation of SACs are introduced. And typical catalytic application of SACs in green synthesis of fine chemicals by means of oxidation reaction, hydrogenation reaction, coupling reaction and other reactions are also introduced. This is the first review paper focusing on the mass preparation techniques of SACs and their applications in fine chemicals production. [ABSTRACT FROM AUTHOR]

CrystEngCommrsc. li/ crystengcomm ISSN 1466- 8033 Volume 26 Number 17 7 May 2024 Pages 2221– 2334 PAPER Edita Garskaite et al. Assessing aspects of solution- based chemical synthesis to convert waste Si solar cells into nanostructured aluminosilicate crystals [Extracted from the article]

Cellulose is the most abundant, renewable carbohydrate resource in nature, providing human society with a broad spread of materials for production and living. Compared with the mature textile and paper industries, technologies for cellulose utilization to produce energy and chemicals are still under development. In particular, the depolymerization of cellulose to glucose and further transformation into various fuel compounds or chemicals has received considerable attention as a sustainable approach to address the energy crisis and environmental issues raised by massive fossil consumption. Among various cellulose derived molecule types, ester is one of the most appealing owing to its unique physicochemical properties, reactivities and functions. This review summarizes recent advances in the chemical synthesis of esters from cellulose and its derivatives. Various esters, including alkyl levulinates, γ-valerolactone, valerates, pentenoates, lactates etc., have been effectively prepared from cellulose feedstock or its downstream platform compounds. The catalytic systems were highlighted with rational integration of the active sites for the tandem reactions involved in the conversions. The kinetics, process integration, selectivity control and catalysis mechanism were also discussed in detail. Finally, an outlook of the future direction, as well as the challenges, for cellulose ester production were also illustrated. [ABSTRACT FROM AUTHOR]

Lignin chemistry is regarded as one of the core components in the field of biomass catalytic conversion. Over the past decade, the catalytic synthesis of value-added chemicals or biofuels via oxidation/reduction depolymerization with lignin as the initial substrate has made extensive progress through ongoing research attempts. However, there are fewer investigations on the conversion of lignin derivatives to nitrogen-containing compounds such as aniline and benzylamine through heterogeneous catalytic amination. On this account, this paper reviews the amination value-added reaction processes of lignin-derived phenols, ethers, carbonyl compounds and alcohols to produce aniline and benzylamine, mainly focusing on cheap catalysts, green solvent systems, nitrogen source systems, and mild reaction conditions, which can provide novel perspectives to promote the processive innovation of a sustainable lignin amination system. The perspectives on the synthesis of lignin-based aniline and benzylamine proposed in this review are intended to offer novel research ideas for further expanding the boundaries of the biomass refining systems involving lignin amination chemistry. [ABSTRACT FROM AUTHOR]

Ferredoxin (Fd) is an electron carrier protein containing a [2Fe–2S] cluster. In this paper, we synthesized Se–Fd, in which four Cys residues coordinated to the cluster are substituted to selenocysteine. After the one-pot segment coupling by the thioester method, followed by deprotection and cluster loading, the desired Se–Fd was successfully obtained. [ABSTRACT FROM AUTHOR]

Droplet microfluidics is an emerging tool in many biological and chemical application areas such as digital polymerase chain reaction (PCR) and in vitro diagnosis because of its extremely small sample volume and wide range of possibilities for on-demand adjustment of droplet properties. Although centrifugal microfluidics has been reported as a viable scheme for droplet generation, there is not much progress as far as droplet manipulation and droplet-based reactions are concerned. In this paper, we report a microfluidic pressure regulator scheme along with the use of microcapillaries for periodic droplet generation and the subsequent fusion. This scheme enables fine control over droplet generation and the fusion process by varying the rotational frequency. To control the solution concentration in droplets, we have implemented several fusion devices, including one-to-one mode using a symmetric structure and ratio-adjustable mode with an asymmetric structure. As an application example, we performed cell transfection using the reported droplet-based technique, which resulted in considerable improvement in terms of transfection efficiency compared to the traditional bulk approach. In another example, we synthesized quasi-2D perovskites with controllable compositions and tunable photoluminescence peaks, thus confirming the volumetric accuracy of this approach down to the nano-liter scale. Compared to the common pressure pulsation approach, our centrifugal force actuation scheme offers the advantages of compactness and highly parallel batch processing. We anticipate that the new scheme will find many applications in cell biology and chemical synthesis. [ABSTRACT FROM AUTHOR]

The paper dwells on the synthesis and diverse studies of cyclically arranged hydrogen bridges in tris-hydroxy aryl Schiff bases. Experimental (IINS, IR, Raman and X-ray) and theoretical (CPMD, DFPT and DFT) studies of tris-hydroxy aryl Schiff bases have been performed in the solid state. This is the pioneer spectroscopic investigation of mutual interactions between hydrogen bridges in a cyclic arrangement. The spectroscopic studies have been carried out by IR, Raman and IINS experimental methods and supported by density functional theory (DFT), plane-wave periodic theory (DFPT) and Car–Parrinello Molecular Dynamics (CPMD) calculations. A study of the impact of steric squeezing on the strength of hydrogen bonds is presented. The remarkable dynamics of the bridged protons in the studied Short Strong Hydrogen Bond (SSHB) has been investigated on the basis of first-principles CPMD calculations. The fundamental investigations of the hydrogen bridge vibrations have been accomplished on the basis of isotopic substitutions (NH → ND and OH → OD) and vibrational Potential Energy Distribution (PED) analysis. [ABSTRACT FROM AUTHOR]

N-Halamine-based antibacterial polymers play a significant role in controlling microbe-associated surface contamination. Hydantoin-containing polymers are usually synthesized by tethering polymerizable moieties to 5,5′-dialkyl hydantoin. However, such approaches sacrifice the imide hydrogen in the molecule, thereby restricting the halogen capture only to the amide nitrogen. In this paper, we report the synthesis of a novel polymerizable hydantoin monomer containing one more amide group in addition to the amide and imide groups already present in hydantoin to maximize the halogen capture and hence its antibacterial activity. The synthesized monomer was copolymerized with methyl methacrylate (MMA) and styrene. The monomer and its copolymers were characterized using 1H and 13C NMR, HRMS, FTIR, XPS, TGA, DTA and GPC. The oxidative chlorine content of the copolymers ranged from 0.9% to 1.21%. The polymers were spin coated onto glass surfaces to study their antimicrobial potential. The polymer-coated glass surfaces exposed to both Gram positive S. aureus and Gram negative E. coli bacteria using standard protocols showed total kill of the bacteria within 15 minutes of exposure. These new hydantoin polymers showed highly superior antibacterial activities compared to many such polymers reported so far in the literature. [ABSTRACT FROM AUTHOR]

A dynamic development of methodologies of analytical flow injection measurements during four decades since their invention has reinforced the solid position of flow analysis in the arsenal of techniques and instrumentation of contemporary chemical analysis. With the number of published scientific papers exceeding 20 000, and advanced instrumentation available for environmental, food, and pharmaceutical analysis, flow analysis is well established as an extremely vital field of modern flow chemistry, which is developed simultaneously with methods of chemical synthesis carried out under flow conditions. This review work is based on almost 300 original papers published mostly in the last decade, with special emphasis put on presenting novel achievements from the most recent 2–3 years in order to indicate current development trends of this methodology. Besides the evolution of the design of whole measuring systems, and including especially new applications of various detections methods, several aspects of implications of progress in nanotechnology, and miniaturization of measuring systems for application in different field of modern chemical analysis are also discussed. [ABSTRACT FROM AUTHOR]

The development of an immobilized enzyme for efficient biocatalysis and catalyst recycling is of great importance in cost-effective and green chemical synthesis, with the hydrolysis of cellulose to glucose for the utilization of lignocellulosic biomass as a prominent and challenging example. We developed a novel concept of engineering temperature-responsive nanobiocatalysts with an upper critical solution temperature (UCST) for efficient catalysis as a soluble catalyst at a temperature ＞UCST and for easy catalyst separation as an insoluble catalyst at a temperature ＜UCST. The first polymeric nanoparticles showing an UCST were fabricated in high yield, and the immobilization of cellulase and cellobiase onto the particles afforded the first UCST-biocatalysts, with high specific enzyme loading and enzyme loading efficiency, an UCST of 13–14 °C, and high retention of the initial hydrolysis activity of the free enzyme at 50 °C (＞UCST). The hydrolysis of insoluble cellulose, such as filter paper and pre-treated oil palm Empty Fruit Bunch (EFB, a waste biomass), with a mixture of the UCST-nanobiocatalysts containing cellulase and cellobiase at 50 °C reached the same catalytic performance as the free enzymes and gave 97% and 93% glucose yield at 2 wt% of cellulase loading, respectively. These catalytic performances are much better than any other known immobilized cellulases, due to the use of soluble catalysts. The catalysts were easily recovered at 4 °C and recycled to retain 71% and 73% productivity in the 8th and 6th reaction cycles for hydrolyzing filter paper and pre-treated EFB, respectively. The engineered UCST-nanobiocatalysts are potentially useful for the practical green hydrolysis of cellulose to glucose. [ABSTRACT FROM AUTHOR]

Three new complexes of palladium(ii) floroquinolone drugs (levofloxacin (HLVX), pefloxacin mesylate (HPFX) and lomefloxacin (HLMX)) were prepared in alkaline media at pH = 9. The suggested chemical formula was assigned as [Pd(L)2] (where L = LVX, PFX and LMX). These complexes were explored by elementary analyses, conductivity tests, infrared and proton NMR spectroscopy, and thermogravimetric analysis and its deferential tools. The homogeneity, surface morphology and particle size of the as-synthesized solid palladium(ii) complex were investigated using X-ray powder diffraction and transmittance electron microscopy. FT-IR and 1H-NMR spectroscopy techniques. The results reveal that HLVX, HPFX and HLMX fluoroquinolones act as bidentate chelates coordinated to the palladium(ii) central metal ion via the oxygen of carboxylate and carbonyl groups. The palladium(ii) metal ion produces a stable six-membered ring with distorted octahedral structure. The conductivity measurement results deduced that these chelates are non-electrolytic in 1 : 2 stoichiometric ratio. Thermal analysis (TG/DTG) was applied to ascertain the stability of the as-synthesized complexes in comparison to free floroquinolone drugs. The thermal decomposition pathways show that the final residual product is pure PdO. Thermodynamic parameters such as energy of activation E*, entropy ΔS*, enthalpy ΔH* and Gibbs free energy ΔG* of activation were calculated using Coats–Redfern and Horowitz–Metzger non-isothermal techniques. The particle sizes of palladium(ii) complexes were measured within nanoscale range, dependent on morphological tools (XRD and TEM). Molecular docking assessment of the three floroquinolones against prostate cancer mutant 2q7k-hormone receptor is discussed. To our knowledge, this paper presents the first-time synthesis and physicochemical characterizations of a coordination complex of palladium(ii) metal ions with floroquinolone and its use as a medicinal model against cancer cells. [ABSTRACT FROM AUTHOR]

Mesoporous hydroxyapatite (MPHA) particles have recently gained a great deal of interest in a broad range of fields including biomedical fields, wastewater treatment and catalysis. In this paper, we describe a novel and convenient route to synthesise MPHA particles using calcium carbonate nanoparticle templates for the formation of mesopores in HA. In this method, both nano-CaCO3 templates and HA are prepared simultaneously using calcium sucrate as a precursor by allowing the nano-CaCO3 to embed in HA. Mesopores in HA are obtained by removing the template. The porosity of HA is confirmed by Brunauer–Emmett–Teller (BET) analysis and the average pore size (below 50 nm) is determined from Transmission Electron Microscopy (TEM) images. The synthesized material is noncytotoxic as confirmed by cytotoxicity studies, which makes it a potential candidate as a biomaterial for biomedical applications. Furthermore, the MPHA shows a superior adsorption ability towards Pb2+ Ni2+ and Cd2+ in aqueous solutions, and could also be used as an environmental-friendly material for wastewater treatment and water purification. Therefore, we believe that this simple and novel synthesis route for the fabrication of porous HA could be useful in fulfilling the current demand for HA in biomedical and water purification applications. [ABSTRACT FROM AUTHOR]

In this paper we reported the synthesis and the in vitro and the in vivo biological evaluation of linear pseudo-peptides incorporating the N-VGCC blocker tripeptide Phe-NMe-Leu-Tyr(OBz)-NtBu and the biphalin pharmacophore Tyr-d-Ala-Gly-Phe. The novel sequences have been designed by using amino acids of different length to join the two pharmacophores and explore the structure–activity relationships of the novel compounds. [ABSTRACT FROM AUTHOR]

In this paper, we describe the effective synthesis of oxatruxene and its photophysical, electrochemical and structural features that transpire when a methylene unit in a truxene core is replaced by an oxygen atom to yield 5-oxatruxene. This modification broke the C3h symmetry and at the same time introduced a more electronegative structure as revealed by a four-fold increase in the quantum yield as compared to truxene. The derivatives of this material have great potential in optoelectronic devices and in organic photovoltaics. This proposed new synthetic method can be used to introduce other heteroatoms into the truxene system. [ABSTRACT FROM AUTHOR]

In this paper, a novel methodology is introduced for the synthesis of novel 5-methyl-8H-isoquinolino[1,2-b]quinazolin-8-one derivatives based on an efficient immobilized palladium catalyzed intramolecular carbon–carbon bond formation. The novel catalyst is fabricated by immobilization of Pd on phosphinite polyethyleneimine functionalized Fe3O4@SiO2 core–shell nanoparticles (denoted as Pd@OPPh2–PEI–mSiO2 NPs). In this catalyst, PEI moieties act as both a water dispersant and base in the reaction. In the key step, 3-allyl-2-(2-bromophenyl)-2,3-dihydroquinazolin-4(1H)-ones (3a–i) were synthesized via a cyclization reaction between N-allyl-2-aminobenzamides and 2-bromobenzaldehyde. The latter obtained materials then underwent an intramolecular carbon–carbon bond formation in the presence of the Pd@Ph2PO–PEI–mSiO2 catalyst to give 5-methyl-13,13a-dihydro-8H-isoquinolino[1,2-b]quinazolin-8-ones (4a–i). [ABSTRACT FROM AUTHOR]

In this paper, we present an approach for the precisely controlled phase transformation of MnO2 in order to synthesise different compositions of α-/β-MnO2 materials, by adding a trace amount of Zn(acac)2 as the phase transformation-inducing agent in a hydrothermal reaction. The single-atomic dispersion of Zn might reduce the barrier of phase transformation of δ-MnO2 to β-MnO2. The ratio of the Zn species present in the single-atomic dispersions and nanoclusters might dominate the generation of α-MnO2 and β-MnO2. The results of the oxygen reduction reactions indicate that the MnO2 materials have potential applications as promising catalysts in electrochemical catalysis. [ABSTRACT FROM AUTHOR]

A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as illisimonin A from Illicium simonsii. [ABSTRACT FROM AUTHOR]

The applicability of microbial electrosynthesis (MES) for chemical synthesis from carbon dioxide (CO2) requires improved production and energetic efficiencies. Microbial catalysts, electrode materials, and reactor design are the key components which influence the functioning of such processes. In particular, cathode materials critically impact the electricity-driven CO2 reduction process by microorganisms. Interest in cathode surface modifications for improving MES processes is thus consistently increasing. In this paper, the recent developments and spatial modification of cathode materials for microbial CO2 reduction are systematically reviewed. The characteristics of commercially available materials, their modifications, and developments in new materials that have been used as cathodes for MES are summarized. Key cathode–microorganism interactions that led to improved CO2 conversion are then discussed. The cathode surface modification approaches have focused mainly on improving the surface area and surface chemistry of the materials. Although the modified cathode surfaces improved biofilm growth in direct electron uptake based bioconversions, they have achieved lower acetate production rates than that of hydrogen-based MES processes thus far. Research efforts on different materials suggest that the three-dimensional cathodes that can retain more biomass, in particular in hydrogen-based bioconversions, are promising for further improvements in production efficiencies. Further efforts toward reducing the energy inputs for achieving energetically efficient MES processes by using electrocatalytically efficient cathodes are needed. [ABSTRACT FROM AUTHOR]

Engineering an efficient biomolecular circuit often requires time-consuming iterations of optimization. Cell-free protein expression systems allow rapid testing of biocircuits in vitro, speeding the design–build–test cycle of synthetic biology. In this paper, we combine this with droplet microfluidics to densely scan a transcription–translation biocircuit space. Our system assays millions of parameter combinations per hour, providing a detailed map of function. The ability to comprehensively map biocircuit parameter spaces allows accurate modeling to predict circuit function and identify optimal circuits and conditions. [ABSTRACT FROM AUTHOR]

In this paper, functional dialkoxysilanes, (3-((3-chloropropyl)thio)propyl)methyldimethoxysilane, 3-((3-(dimethoxy(methyl)silyl)propyl)thio) propanoic acid, 3-methoxy-3-methyl-2,11-dioxa-7-thia-3-silatridecan-13-ol, and 3-methoxy-3-methyl-2,11,14,17,20,23,26,29,32-nonaoxa-7-thia-3-silatritriacontane, are first obtained by reacting functional alkenes with 3-(dimethoxy(methyl)silyl)propane-1-thiol in near-quantitative yields using a simple, efficient and photoinitiated thiol–ene click reaction. Then, functional polysiloxanes are synthesized from their corresponding functional dialkoxysilane monomers. This two-step method is a novel and efficient way of synthesizing functional polysiloxanes. The functional polysiloxanes show obvious fluorescence properties, which are assumed to be generated from unconventional chromophores. Furthermore, a series of copolymers (PETHs) with mercaptopropyl and polyether side chains are also obtained. They are successfully used for hydrophilic modification of a poly(styrene-b-butadiene-b-styrene) triblock copolymer. The PETH-based blue-light-emitting silicone elastomer is synthesized first via a thiol–ene click reaction, and it exhibits wonderful hydrophilicity, which may be useful in biomedical fields. [ABSTRACT FROM AUTHOR]

A mild and efficient synthesis of N-acylhydrazones has been developed, applying a simple grindstone procedure, leading to a library of 51 examples exhibiting a broad variety of structural features, 21 of them described for the first time in this paper. This methodology works without any organic solvent under the catalysis of acetic acid at room temperature, promotes the formation of essentially pure crude products, and avoids tedious work-up and the use of harmful solvents, as well as energy consumption. In addition, it leads to the stereoselective formation of N-acylhydrazones, as supported by NMR analysis. [ABSTRACT FROM AUTHOR]

In this paper we report the one pot functionalization of the carbon–carbon double bonds of triglycerides via a cascade hydroaminomethylation (HAM)/hydrohydroxymethylation (HHM) reaction. The carbon–carbon double bonds are first hydroformylated using a Rh-catalyst. The produced aldehydes react with secondary amines to yield enamines which are then reduced to tertiary amines. Interestingly, the latter act as ligands of Rh-species capable of hydrogenating the remaining formyl groups into alcohols. As a result, the final triglycerides are substituted by both aminomethyl and hydroxymethyl groups. Of interest, no phosphane ligand is used to stabilize the Rh-species. Moreover, the proportion of aminomethyl and hydroxymethyl groups grafted onto the triglyceride fatty chains can be finely adjusted by a careful choice of the experimental conditions, especially the nature and the amount of the amine, the reaction temperature, and the CO/H2 pressure. The resulting amino-hydroxylated triglycerides are unprecedented biosourced building blocks whose applications could be of major interest, especially in the field of polymer chemistry. [ABSTRACT FROM AUTHOR]

This paper presents the synthesis, X-ray studies, spectroscopic characterization and variable temperature magnetic investigations and DFT calculation of four novel thiocyanato Cu(ii) compounds [Cu(mpz)2(NCS)2]n·nH2O (1), {[Cu2(dmpz)4(NCS)4][Cu(dmpz)(NCS)2]}n·2nMeOH (2) [(bdmpzm)CuII(SCN)2(μ1,3-SCN)CuI(bdmpzm)]n (3) and [Cu(bpzpy)(NCS)2] (4). Three of them (1, 2 and 3) display one-dimensional coordination structures while complex (4), incorporating a tridentate N-donor ligand, possesses a 0D molecular structure. Complex 3 belongs to a relatively rare group of mixed-valence CuII/CuI coordination polymers. [ABSTRACT FROM AUTHOR]

The synthesis, single-crystal structure characterization and detailed magnetic study of a homometallic hexanuclear CuII cluster [Cu6(μ3-OH)2(ppk)6(H2O)2(NO3)4] (1) and a three-dimensional (3D) compound [{MnCu2(dpkO2H)2(dpkO2)N3}·(NO3)·H2O]n (2) (ppk = phenyl-2-pyridyl ketoxime; dpk = di-2-pyridyl ketone) consisting of heterometallic MnII–CuII hexanuclear cores as secondary building units are reported in this paper. In compound 1, two symmetry-related Cu3 triangles consisting of a hydroxido-bridged trinuclear unit, [Cu3(μ3-OH)(ppk)3(H2O)(NO3)]+, are assembled through nitrate bridging giving rise to the homometallic Cu6 cluster. Compound 2 contains heterometallic {MnII2CuII4} cores, which are further connected to each other through an azido bridging ligand in all the crystallographic directions, resulting in a 3D metal–organic framework. Construction of such a heterometallic 3D framework from {MnII2CuII4} units is until now, unknown. Magnetic studies of both 1 and 2 were performed in detail and both compounds show dominant antiferromagnetic interaction in the respective clusters. Compound 1 reveals significant spin frustration and anti-symmetric exchange interaction in the trinuclear cores, with a significantly high value of Jav (−655 cm−1). Furthermore, compound 2 exhibits a dominant antiferromagnetic interaction, which is also supported by an extensive magneto-structural correlation which considers the different magnetic pathways. [ABSTRACT FROM AUTHOR]

This paper reports the TiO2 seed-assisted hydrothermal growth of VO2 films on a quartz substrate. The rutile TiO2 seed layer can promote the oriented growth of VO2(M) at the initial stage of the hydrothermal reaction, and then, the VO2(D) phase further grows on top of the VO2(M) layer. It was found that a pure VO2(M) thin film can grow on the TiO2 seed layer at a temperature as low as 200 °C. A subsequent annealing treatment can transform the VO2(D) phase to the VO2(M) phase. The VO2(M)/TiO2 composite films display thickness-dependent optical and electrical performance, and nearly 55% infrared modulation at 3 μm and 3 orders of magnitude resistance modulation can be realized. Our results demonstrate important progress in growth of VO2(M) thermochromic thin films, which will find potential application in constructing VO2-based switching devices. [ABSTRACT FROM AUTHOR]

Here, we for the first time synthesized bimetallic Cu/Ag dendrites on graphene paper (Cu/Ag@G) using a facile electrodeposition method to achieve efficient SERS enhancement. Cu/Ag@G combined the electromagnetic enhancement of Cu/Ag dendrites and the chemical enhancement of graphene. SERS was ascribed to the rough metal surface, the synergistic effect of copper and silver nanostructures and the charge transfer between graphene and the molecules. [ABSTRACT FROM AUTHOR]

In this paper, a series of stable Sn-containing heteroaromatic conjugated oligomers, dialkyl dithieno[3,2-b:2′,3′-d]stannole (DTSn) and stannafluorene (SnF) derivatives, were designed and synthesized employing a new synthetic route. The distinctive feature of this route is that terminal groups are linked to the backbone before the stannole cycle closed, which can avoid the cleavage of stannole in the Stille reaction. Three Sn-heteroaromatic small molecules, DTSn-1, SnF-1 and SnF-3, have been obtained and characterized. The density functional theory (DFT) calculations show that the alkyl groups are further displaced from the conjugated backbone due to the larger atomic radius of Sn, which allows a stronger π-stacking interaction to occur. Interestingly, the fluorescence intensity of DTSn-1 is increased in the presence of Al3+ due to interaction between Al3+ and Sn. However, the emissions of the three Sn-containing oligomers can be quenched by Ru3+, which renders these compounds potential candidates as fluorescence detectors for Ru3+. [ABSTRACT FROM AUTHOR]

A series of l-phenylalanine ionic liquids (ILs), l-tyrosine ILs, tertiary amino analogues and proposed transformation products (PTPs) have been synthesised. Antimicrobial toxicity data, as part of the green chemistry metrics evaluation and to supplement preliminary biodegradation studies, was determined for ILs, tertiary amino analogues and PTPs. Good to very good overall yields (76 to 87%) for the synthesis of 6 ILs from l-phenylalanine were achieved. A C2-symmetric IL was prepared from TMS-imidazole in a one-pot two-step method in excellent yield (91%). Synthesis of the l-tyrosine IL derivatives utilised a simple protection group strategy by using an extra equivalent of the bromoacetyl bromide reagent. Improvements in the synthesis of the α-bromoamide alkylating reagent from l-phenylalanine were achieved, directed by green chemistry metric analysis. A solvent switch from dichloromethane to THF is described, however the yield was 15% lower. Antimicrobial activity testing of l-phenylalanine ILs, l-tyrosine ILs, tertiary amino analogues and PTPs, against 8 bacteria and 12 fungi strains, showed that no compound had a high antimicrobial activity, apart from an l-proline analogue. In this exceptional case, the highest toxicity (IC95 = 125 and 250 μM) was observed towards the two Gram positive strains Staphylococcus aureus and Staphylococcus epidermidis respectively. High antimicrobial activity was not found for the other bacteria or fungi strains screened. The limitations of the antimicrobial activity study is discussed in relation to SAR studies. Preliminary analysis of biodegradation data (Closed Bottle Test, OECD 301D) is presented. The pyridinium IL derivative is the preferred green IL of the series based on synthesis, toxicity and biodegradation considerations. This work is a joint study with Kümmerer and co-workers and the PTPs were selected as target compounds based on concurrent biodegradation studies by the Kümmerer group. For the comprehensive biodegradation and transformation product analysis see the accompanying paper. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis, structure and photophysical studies of four new complexes of conformationally flexible 6-chloro-4-phenyl-2-(pyridin-2-yl)quinazoline ligand (L) with Zn(ii). The coordinating ability of the ligand and geometrical preferences of the resultant complexes are tuned by varying the anion of the metal salt as confirmed by structural and DFT studies. The choice of the metal salt (especially anion) directs the stabilisation of different conformations of the ligand arising out of twisting of the pyridyl ring with respect to the quinazoline ring, resulting in complexes with different nuclearity (monomer/dimer) as well as different coordination geometries (tetrahedral/trigonal bipyramidal/octahedral). Photophysical properties are also found to be tuned due to conformational changes on complexation. DFT studies on the ligand establish the conformationally stable forms as observed in the reported structures. [ABSTRACT FROM AUTHOR]

Selenium nanoparticles (SeNPs) have attracted great attention because of their superior optical properties and wide utilization in biological and biomedical studies. This paper reports an environmentally benign procedure of greener monodispersible SeNP synthesis using the reducing power of Trigonella foenum-graecum extract, characterization and their protective effect against unfolded (Herring sperm DNA) hsDNA. We investigated the anti-cancer activity of SeNPs against MCF-7, MDA MB 435 and COLO-205 cells. The photocatalytic activity of SeNPs was investigated for the degradation of a Sunset Yellow FCF (SYFCF) dye using ultraviolet-B light. The reduction of the Se ion to SeNPs was monitored by ultraviolet-visible spectroscopy (UV-vis). The size and morphology of the SeNPs were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Dynamic Light Scattering (DLS). The SeNPs were stable, and the diameter was homogeneous at around 5–12 nm. Interactions of various concentrations of SeNPs with hsDNA were systematically investigated by UV-vis, fluorescence, circular dichroism (CD), polarimetry and FTIR spectroscopy under physiological conditions. The results from fluorescence spectroscopy indicated that SeNPs quenched the fluorescence intensity of hsDNA with increasing concentrations. The modified Stern–Volmer quenching rate constant Ksv, binding constant K and binding sites n at different temperatures and the corresponding thermodynamic parameters ΔH°, ΔG° and ΔS° were calculated. Hoechst 33258 and methyl green (MG) site markers, melting experiment (Tm), viscosity measurements and sequence specificity verification by DNA bases clarified that SeNPs bind to hsDNA via a groove site. The rate of photocatalytic degradation of the SYFCF dye in the presence and absence of photocatalysts (SeNPs) was studied using UV-vis, the results showed appreciable degradation of the SYFCF dye. Our results suggested that nano Se can be used as a promising selenium species with potential application in cancer treatment. These nanoparticles were found to be the most active cytotoxic agent prepared in a new green synthesis manner, causing ＞50% inhibition of MCF-7, MDA MB-435 and COLO-205 cell proliferation at concentrations ＜10−7 M. Hence these SeNPs could be recognized as promising materials for biomedical applications. [ABSTRACT FROM AUTHOR]

In this paper, we report a novel morphology-controlled synthetic method. Platinum (Pt) nanoparticles with three kinds of morphology (aggregation-like, cube-like and globular) were grown on the surface of graphene oxide (GO) using a simple gas–liquid interfacial reaction and Pt/GO nanocomposites were obtained successfully. According to the experimental results, the morphology of the Pt nanoparticles can be controlled by adjusting the reaction temperature with the protection of chitosan. The obtained Pt/GO nanocomposites were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). Then the Pt/GO nanocomposites with the three kinds of morphology were all used to fabricate electrochemical sensors. The electrochemical experimental results indicated that compared with various reported electrochemical sensors, the Pt/GO modified sensors in this work exhibit a low detection limit, high sensitivity and an extra wide linear range for the detection of nitrite. In addition, the synthesis of Pt particles based on a gas–liquid interfacial reaction provides a new platform for the controllable synthesis of nanomaterials. [ABSTRACT FROM AUTHOR]

In this paper, a facile precursor phosphidation route was designed for morphology controlled synthesis of Ni2P nanostructures, employing NiCl2 and NaH2PO2 as the initial reactants in the presence of polyvinylpyrrolidone (PVP) and hexamethylenetetramine (HMT). Experiments showed that under the same hydrothermal conditions, NiHPO3·H2O nanorods and Ni nanospheres were separately obtained via only changing the original amount of HMT. The as-obtained NiHPO3·H2O nanorods and Ni nanospheres could be used as the precursors in low-temperature phosphidation reactions under a N2 atmosphere. Under the same phosphidation conditions, Ni2P nanorods and nanospheres were formed, respectively. The precursor and the final products were characterized by powder X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical performance and the catalytic properties of the Ni2P nanorods and nanospheres were investigated. It was found that the as-obtained Ni2P nanostructures displayed marked shape-dependent properties: the Ni2P nanorods presented better electrochemical performance, such as higher specific capacitance and more stable cycle features, and stronger catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in an excess NaBH4 solution than the Ni2P nanospheres. [ABSTRACT FROM AUTHOR]

This paper presents the first dysprosium(iii) complex, [{(MeMeArO)3tacn}DyIII(THF)] (1Dy), that shows oxygen-sensitive luminescence. The synthesis, structure and oxygen-sensitive luminescence properties of 1Dy are reported (Φ = 0.050 and τ = 17.7 μs under N2, Φ = 0.011 and τ = 4.1 μs under O2 and KSV = 305 M−1 in THF; KSV = 0.0077%−1 in polystyrene film). The oxygen sensitive mechanism of 1Dy is discussed based on the photophysical properties of the corresponding gadolinium(iii) complex, [{(MeMeArO)3tacn}GdIII(THF)]. [ABSTRACT FROM AUTHOR]

This paper reports an effective route for the syntheses of hydroxy carbamates from the reaction of CO2, epoxides and amines catalyzed by a Au/Fe2O3 catalyst. Under the optimized reaction conditions, various hydroxy carbamates were successfully synthesized with 92–98% isolated yields. The catalyst could be reused for several runs without deactivation. A plausible reaction mechanism was proposed by which the hydroxy carbamate was formed through an ammonium carbamate intermediate and the catalyst mainly promoted further nucleophilic addition between the epoxide and ammonium carbamate. [ABSTRACT FROM AUTHOR]

Spinel-like Mn1.5Al1.5O4 is an unstable compound whose decomposition is induced by partial oxidation of Mn2+ ions in the temperature range of 300–800 °C in air. According to XRD, two spinel-like phases, Mn0.4Al2.4O4 and Mn2.8Al0.2O4, are formed during both cooling and heating of Mn1.5Al1.5O4. In this paper, we have studied microstructural changes of Mn1.5Al1.5O4 to understand its decomposition mechanism. During heating, low-temperature oxidation takes place and decomposition proceeds via a nucleation and growth mechanism. As a result slightly Al-doped β-Mn3O4 nanoparticles are formed on the surface of the parent spinel particles. On the contrary, cooling leads to high-temperature oxidation that results preferably in spinodal decomposition and formation of alternating Mn- and Al-rich lamellas of nanosized thickness. The present study provides a fundamental reference for the nanostructure design of a Mn–Al–O system and probably some other ones subjected to oxidative decomposition. [ABSTRACT FROM AUTHOR]

Covering: up to 2015 In this highlight we describe two case studies from our laboratory, involving the biomimetic syntheses and the biological mechanism elucidation of the bioactive oligomeric sesquiterpenoids, (+)-ainsliadimer A (4) and (−)-ainsliatrimer A (5). Ainsliadimer A possesses potent anti-inflammatory activity by inhibition of the NF-κB signalling pathway via binding at a previously untargeted allosteric site. (−)-Ainsliatrimer A induces apoptosis in cancer cells by activation of PPARγ. Furthermore, we highlight a new bioorthogonal ligation (TQ-ligation) developed in our laboratory which facilitates the target identification of complex natural products via pre-target fluorescence imaging and affinity chromatography. Generally, this paper will discuss the complete process from total synthesis to biological studies of complex natural products, and from the establishment of new bio-orthogonal chemistry to successful target identification. Our approach provides a systematic and efficient methodology for addressing the challenge of natural product target identification. [ABSTRACT FROM AUTHOR]

Cauliflower-like NiCo2S4 nanoparticles (NPs) for use as battery-type materials have been synthesized via a simple one-step route solvothermal method with thioacetamide (TAA) as the sulfur source. The synthesis of the Ni–Co precursors and the S2− anion exchange reactions occur at the same time, which is time-effective and cost-effective compared to other methods. The obtained NiCo2S4 NPs display very competitive electrochemical performance (a specific capacitance of 2480 F g−1 is achieved at a current density of 0.5 A g−1, excellent rate capability with 68% of the original capacitance remained at 10 A g−1 and ideal cycle stability with 80% capacitance remained after 3000 cycles) with high mass-loading (5 mg cm−2). In addition, low-cost activated balsam pear pulp (ABPP) is developed as a capacitor-type carbon material for supercapacitors with ideal electrochemical performances. The asymmetric hybrid capacitors (AHCs) are further assembled into pouch cells using battery-type NiCo2S4 NPs as the positive electrode, capacitor-type ABPP as the negative electrode and flexible carbon papers as the current collector. The AHCs demonstrate high power density (3.52 kW kg−1 at an energy density of 3.72 Wh kg−1) and cycle stability (72.4% after 9000 cycles). [ABSTRACT FROM AUTHOR]

The dark color of industrial lignin is the main obstacle for their high value-added use in areas such as sunscreen or dyestuff dispersants. Here, a one-step method for reducing the color of lignin is presented and the structural changes of the whitened lignin are characterized by UV, FTIR, NMR, GPC, DLS, AFM, HS-GC and potentiometric titration. The results show that the content of aromatic ring, methoxyl and phenolic hydroxyl groups in the alkali lignin (AL) decreases, while the content of carboxylic groups increases when it is exposed to UV in THF. AL experiences a darkening process before it is gradually whitened. The blue shift of the UV spectrum and the decrease in size and molecular weight indicate AL is not only intermolecular and intramolecular disaggregated, but also partially depolymerized when light colored lignin is obtained. This simple but efficient whitening method is successfully practised in bleaching. The white degree of raw paper increases from 0.438 to 0.917 after being irradiated under sunshine for 3 days. [ABSTRACT FROM AUTHOR]

This paper will review the crystal growth mechanism of zeolites and discuss some of the latest findings in this field. A great effort has been dedicated in recent years to improving the fundamental understanding of zeolite crystal growth during the synthesis process, with the overall aim of increasing control over the zeolite properties and structure. The latest studies on zeolite crystallization in colloidal (clear) suspensions, prepared by addition of organic and inorganic structural directing agents, in comparison to traditional gel synthesis and seed-approach will be discussed. Further understanding of the imperative dependence of zeolite crystallization kinetics' on the nature and mode of mixing of the initial reactants, leading to the formation of amorphous particles, intermediates, and final crystalline zeolites will be presented. [ABSTRACT FROM AUTHOR]

In this paper, we designed and synthesized a novel TBET-based ratiometric fluorescent chemodosimeter, RH-Au, for Au3+. It was found that the probe RH-Au displayed highly selective, sensitive and naked-eye detection upon the addition of Au3+. The probe RH-Au can be used in the pH range 6.0–7.5 and the detection limit was determined to be as low as 2.91 nM (0.57 ppb). We also demonstrated a successful application of imaging Au3+ in living cells using RH-Au. [ABSTRACT FROM AUTHOR]

Hollow mesoporous silica nanospheres with high-density functional groups were successfully prepared based on an effective basic selective etching strategy. In this work, thiol-functionalized hollow mesoporous silica nanospheres were synthesized by the etching of cyano-SiO2@thiol-SiO2and vinyl-SiO2@thiol-SiO2core–shell composite particles. The composite particles were fabricated, respectively, viaa two-step sol–gel reaction of different organosilanes. The different alkali resistance between the inner core and the outer shell of the composite particles is the key to fabricating hollow silica nanospheres in this paper. When the core–shell composite particles were treated with Na2CO3and NaOH, the thiol functionalized outer shell showed higher stability than the cyano and vinyl functionalized inner core. The inner core, which is less stable under alkaline conditions, will be etched off in base, resulting in a hollow structure. Transmission electron microscopy (TEM) results demonstrate that large-scale hollow mesoporous silica nanospheres can be obtained through this method. In addition, it is also found that the morphology of samples may be regularly changed by manipulating the concentration of alkali in the etching process. Fourier transform infrared (FT-IR) and energy dispersive spectrometry (EDS) confirm that the thiol groups exist in the organic functionalized hollow mesoporous silica nanospheres obtained. We expect that this facile strategy can be extended to fabricate organic functionalized hollow mesoporous silica nanospheres with more other valuable functional groups. [ABSTRACT FROM AUTHOR]

This paper describes the pyrolysis of pyridinedicarboxylate-containing Zn-based metal–organic frameworks (MOFs) to form nanoporous carbons with accessible N dopants to adsorb CO2. The optimal materials were synthesized using N-heterocycle additives to control the amount of coordinated DMF in the base MOF structure, thereby increasing its thermal stability prior to pyrolysis. [ABSTRACT FROM AUTHOR]

Phosphorus and microporous aluminosilicates, better known as zeolites, have a unique but poorly understood relationship. For example, phosphatation of the industrially important zeolite H-ZSM-5 is a well-known, relatively inexpensive and seemingly straightforward post-synthetic modification applied by the chemical industry not only to alter its hydrothermal stability and acidity, but also to increase its selectivity towards light olefins in hydrocarbon catalysis. On the other hand, phosphorus poisoning of zeolite-based catalysts, which are used for removing nitrogen oxides from exhaust fuels, poses a problem for their use in diesel engine catalysts. Despite the wide impact of phosphorus–zeolite chemistry, the exact physicochemical processes that take place require a more profound understanding. This review article provides the reader with a comprehensive and state-of-the-art overview of the academic literature, from the first reports in the late 1970s until the most recent studies. In the first part an in-depth analysis is undertaken, which will reveal universal physicochemical and structural effects of phosphorus–zeolite chemistry on the framework structure, accessibility, and strength of acid sites. The second part discusses the hydrothermal stability of zeolites and clarifies the promotional role that phosphorus plays. The third part of the review paper links the structural and physicochemical effects of phosphorus on zeolite materials with their catalytic performance in a variety of catalytic processes, including alkylation of aromatics, catalytic cracking, methanol-to-hydrocarbon processing, dehydration of bioalcohol, and ammonia selective catalytic reduction (SCR) of NOx. Based on these insights, we discuss potential applications and important directions for further research. [ABSTRACT FROM AUTHOR]

Large magnetoresistance (MR) effects in bismuth depend on crystallinity and grain size. In this paper, we report for the first time Bi micron particles (BMPs) with large MR that can be produced on a large scale and with high quality through a simple low-temperature solvothermal reduction route in a highly alkaline media system. Almost all the BMPs have the very interesting structural characteristic of a rounded truncated octahedral shape. In addition, the reaction and growth mechanism of the truncated octahedral BMPs is proposed on the basis of experimental data. It starts with an alkaline media-homogeneous nucleation, and then small crystal nuclei aggregate into irregular nanoflakes and assemble into polycrystalline microspheres at the lead of the CTAC soft template with the nucleus growing at the same time. Then surface recrystallizations happen to form the truncated octahedral bismuth micron particles via Ostwald ripening. With prolonged time, recrystallization continues from the surface to the core anisotropically. Moreover, the MR of the truncated octahedral BMPs can reach up to 130% at room temperature (T = 300 K) and 700% at temperature T = 10 K in an 8 T field, respectively, with nonhysteretic and quasi-linear field dependence. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of monoclinic bismuth vanadate (BiVO4) by the oxidant peroxide method with crystallization under hydrothermal conditions, and its catalytic performance on the photodegradation of pollutants under visible light. The as-synthesized BiVO4 materials were characterized by means of X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and scanning electron microscopy (SEM). Hydrothermal treatment above 80 °C was required to obtain pure monoclinic BiVO4 phase by releasing V5+ ions from vanadium peroxo complexes. With the increase in hydrothermal reaction temperature, the particle size decreased. All BiVO4 samples presented large size and shape distribution and band gap of approximately 2.40 eV. The as-prepared BiVO4 catalysts showed high photoactivity for decomposition of model pollutants, methylene blue (MB) and rhodamine B (RhB) dyes, under exposure to visible light. The photodegradation mechanism was evaluated by adding scavengers, DMSO and KBrO3, which were used to probe ṖOH radical and conduction band (CB) electrons, respectively. It was observed that photodegradation of MB and RhB dyes is caused by the action of ṖOH radicals, and that BiVO4 CB electrons do not have reduction potential sufficiently high to reduce dissolved oxygen to O2−Ṗ. It was proven that the indirect mechanism, i.e.ṖOH radical formation, plays the major role on the BiVO4-assisted photodegradation process. [ABSTRACT FROM AUTHOR]