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The ingredients of makeup removers are very complex, and it is difficult to distinguish the brand and authenticity of makeup removers simply by employing traditional ingredient analysis. In this work, based on the controlled self-assembly of perylene probes, a novel fluorescence sensing strategy was successfully developed to distinguish the brand and authenticity of makeup removers. Four charged perylene derivatives were synthesized and utilized as the sensing elements. It was found that the perylene probes were soluble and existed in equilibrium between their aggregated and free monomeric forms in neutral aqueous solution. The disaggregation of the probes occurred in the presence of surfactants or alcohols. Moreover, various degrees of disaggregation and the corresponding turn-on fluorescence were observed in the presence of different kinds of surfactants and alcohols. A novel four-channel sensor array based on the probes was then established, and successfully utilized for the discrimination of alcohols and surfactants. In addition, based on the fact that surfactants and alcohols are the main components of makeup removers, the sensor array was also successfully employed to discriminate makeup remover waters. Using our devised sensor array, makeup removers could be easily distinguished from the daily used liquid goods, and the nine brands of commercial makeup removers could also be easily differentiated from each other. The authenticity of makeup removers could also be identified with high accuracy. [ABSTRACT FROM AUTHOR]

Annulated 1,4,2,5-diazadiborinine 3 has been synthesized and fully characterized. Computational studies revealed that compound 3 features a relatively small HOMO–LUMO gap (2.61 eV). When 3 was treated with elemental grey selenium (Se), oxidative addition of Se proceeded regioselectively at the boron centres of 3 to give a bicyclo[2.2.2] molecule 4 involving a B–Se–Se–B unit, which can be deemed a heavier analogue of dibora-peroxide. [ABSTRACT FROM AUTHOR]

A novel sensing strategy for acetylcholinesterase (AChE) and alpha-fetoprotein (AFP) is developed, based on the perylene probe monomer to excimer fluorescence transformation induced by the in situ generation of a metal coordination polymer. In the presence of AChE, acetylthiocholine chloride was hydrolyzed to thiocholine. Ag+ and the produced thiocholine formed a positively charged metal coordination polymer, which induced the aggregation of a negatively charged perylene probe and the formation of probe excimer emission. The intensity ratio of excimer to monomer emission was proportional to the AChE concentration. A sensing method for AChE was thus established with a detection limit of 0.02 mU mL−1. The excimer emission with a large Stokes shift could avoid the interference of background fluorescence from complex biological samples, and thus achieved selective and sensitive detection of AChE. In addition, a fluorescence immunoassay strategy for AFP was then developed. Gold nanoparticles (AuNPs) co-immobilized with acetylcholinesterase and the AFP antibody as the capture and amplification probe were first prepared. In the presence of AFP, the sandwich structure was formed by immunological recognition. The hydrolysis of acetylthiocholine was catalyzed by AChE on the AuNPs, and the metal coordination polymer was then formed which resulted in the aggregation of the perylene probe and the formation of the excimer emission. The proposed sensing method offers a new strategy for the detection of other biomarkers. [ABSTRACT FROM AUTHOR]

The addition of phenyl lithium (PhLi) to an aromatic 1,3,2,5-diazadiborinine (1) afforded isolable ionic species 2, which can be deemed as an inorganic analogue of a Janovsky complex. X-ray diffraction analysis and DFT studies of 2 indicate the delocalization of π-type electrons mainly over the C–B–C unit in the central B2C2N2 six-membered ring. The reactions of 2 with methyl iodide (MeI) and chloro(tricyclohexylphosphine)gold(i) (Cy3PAuCl) gave 3 bearing a B–Me bond and 4 featuring a B–Au bond, respectively, demonstrating the nucleophilic properties of the tricoordinate boron center in 2. [ABSTRACT FROM AUTHOR]

The reaction of [LCH2] (1, L = 1,3-C6H4(PhPS)2) and M(NMe2)4 (M = Hf, Zr) in toluene at 110 °C afforded a mixture of group 4 metal complexes [{LC(S)}2M] [M = Hf (2), Zr (3)] and [1,3-C6H4(PhPS)(PhP)CH2]. The reactions appear to proceed through the formation of metal bis(carbene) complexes, [LC=M=CL], which then undergo an intermolecular sulphur transfer reaction with the P=S bond of [LCH2] to form 2 and 3, and the byproduct is [1,3-C6H4(PhPS)(PhP)CH2]. In addition, the reaction of 1, [CH2(PPh2S)2] (4) and M(NMe2)4 in refluxing toluene gave a mixture of [{LC(S)}M(NHMe2){C(PPh2S)2}] [M = Hf (5), Zr (6)], [1,3-C6H4(PhPS)(PhP)CH2] and [CH2(PPh2S)(PPh2)]. Moreover, the intermolecular sulfur transfer reaction is evidenced by the reaction of the tin(ii) 1,3-benzodi(thiophosphinoyl)methandiide complex [{μ-1,3-C6H4(PhPS)2C}Sn]2 (7) with two equivalents of elemental sulfur in CH2Cl2 at ambient temperature to give [{1,3-C6H4(PhPS)2CS}2Sn] (8). Compounds 2, 3, 5, 6, and 8 were characterized by NMR spectroscopy and X-ray crystallography. [ABSTRACT FROM AUTHOR]

A novel fluorescence turn-on strategy for glucose sensing is demonstrated. The fluorescence of a perylene probe could be quenched by the silver nanoparticles (Ag NPs). The Ag NPs could be etched by H2O2 generated from the enzymatic oxidation of glucose. And efficient probe fluorescence recovery was detected. [ABSTRACT FROM AUTHOR]

Sodium bisulfite is a food additive, and its excessive intake can be harmful to human health. In this work, a new method for detecting bisulfite was developed based on the Etch-Cu-HCF nanozyme with enhanced polyphenol oxidase-like (PPO-like) activity. The Etch-Cu-HCF nanozyme was obtained from the ammonia erosion of the Cu-HCF nanozyme, and its PPO-like activity was enhanced by nearly 100% than that of the Cu-HCF nanozyme. It is possible that the Cu/Fe ratio of Etch-Cu-HCF increased after ammonia etching and more copper active sites were exposed. In addition, based on the PPO-like activity of the Etch-Cu-HCF nanozyme, 2,4-dichlorophenol (2,4-DP) can be oxidized to its corresponding quinone-like product, which can combine with 4-aminoantipyrine (4-AP) to obtain colorful products with UV absorption at 510 nm. However, the quinone-like product can be consumed by bisulfite via an addition reaction, which reduces the binding of the quinone-like product to 4-AP, resulting in a decrease in the UV absorbance of the system at 510 nm. Therefore, a new method for the detection of bisulfite was developed. The detecting range was 0–50 μM, and the detecting limit was 0.47 μM. The method has good selectivity and was successfully applied for the analysis of bisulfite in food. [ABSTRACT FROM AUTHOR]

A metal-free tandem double hydrophosphination of extended conjugated indandiones has been established. Mechanistic investigations confirmed the consecutive manner of the nucleophilic addition reaction. Complexation of the generated keto-diphosphine resulted in the formation of an unexpected tridentate bridging ligand with an anionic P,O-bidentate and a neutral P-monodentate coordination mode on two palladium units. In the presence of an external chiral auxiliary, the coordinated diphosphines could be separated into their enantiomeric forms. [ABSTRACT FROM AUTHOR]

In this work, we report the successful construction of two chiral porous metal-metallosalan frameworks (1 and 2) by using dipyridylfunctionalized chiral Al(salen) and Mn(salen) separately, and then a composite crystal MOF 3 was constructed with 1 inside, which was encapsulated by 2 outside. The resulting composite crystal appeared to be highly enantioselective for the alkene epoxidation/epoxide aminolysis reactions with a maximum ee of 97%. [ABSTRACT FROM AUTHOR]

Given the periodic relationship of phosphines and arsines, is remodeling the catalytic asymmetric hydrophosphination reaction an efficient manner to develop the corresponding hydroarsination reaction? Herein, a chiral PCP-Pd(ii) pincer complex adept at generating enantioenriched phosphines was examined in the asymmetric hydroarsination reaction. Under distinct conditions, tertiary phosphines and arsines were generated in excellent yields (P: 96%, As: 91%) and ees (P: 90%, As: 85%). While secondary arsine reagents were not direct substitutes for the analogous phosphines, important parameters were identified which increased yield and ee of the hydroarsination reaction. Unlike the PCP-PdOAc pincer complex commonly used for hydrophosphinations, hydroarsination reactions involved a PCP-PdCl catalyst with 10 equiv. of CsF for optimal performance. Notable differences between the two reactions and their workup procedures were highlighted to guide further developments in the field. Lastly, respective mechanisms were proposed and contrasted for the activation of HEPh2 (E = P, As). [ABSTRACT FROM AUTHOR]

The reactions of germylone 1 with one equivalent of [M(COD)Cl]2 (M = Ir, Rh) afforded the germylone-bridged bimetallic complexes 2 and 3, which have been spectroscopically and structurally characterized. Density functional theory (DFT) studies reveal the relatively strong interactions between the Ge atom and these metals. By the reaction of [Rh(COD)Cl]2 with CO followed by addition of 1, a complex 4 involving a Rh–Ge–Rh–Ge–Rh chain was also synthesized. [ABSTRACT FROM AUTHOR]

A growing number of halogenated organic compounds have been identified as hazardous pollutants. Although numerous advanced oxidative processes have been developed to degrade organohalide compounds, reductive and nucleophilic molecular approaches to dehalogenate organic compounds have rarely been reported. In this manuscript, we employ nickel(ii)-ate complexes bearing the o-phenylenebis(N-methyloxamide) (Me2opba) tetraanionic ligand as nucleophilic reagents that can react with alkyl halides (methyl up to the bulky isobutyl) by O-alkylation to give their respective imidate products. Four new nickel(ii) complexes have been characterized by X-ray crystallography, and the salient structural parameters and FT-IR vibrational bands (∼1655 cm−1) concur with their assignment as the imidate tautomeric form. To the best of our knowledge, this is the first report on the nucleophilic reactivity of NiII(Me2opba) with halogenated organic compounds. The parent nickel(ii) Me2opba complex exhibits reversible electrochemical oxidation and reduction behavior. As a proof of concept, NiII(Me2opba) and its alkylated congeners were utilized for the electrocatalytic reduction of chloroform, as a representative, simple polyhalogenated organic molecule that could arise from the oxidative treatment of organic compounds by chlorination. Modest turnover numbers of up to 6 were recorded, with dichloromethane identified as one of the possible products. Future efforts are directed towards bulkier -ate complexes that possess metal-centered instead of ligand-centered nucleophilic activity to create more effective electrocatalysts for the reduction of halogenated organic compounds. [ABSTRACT FROM AUTHOR]

A catalytic asymmetric hydroarsination reaction of an activated alkene viz. (E)-nitrostyrene was developed using chiral PCP Pt-, Pd- and Ni-pincer complexes as catalysts. The corresponding chiral tertiary arsine adduct was obtained in ees of up to 80% under mild reaction conditions using the PCP Ni–Cl pincer catalyst. The arsine adduct was furnished with catalyst loadings of 1–5 mol% and the reaction duration ranging from ＜5 min to 180 min. The subsequent coordination of the hydroarsination product to gold(i) chloride allowed for the confirmation of the stereochemistry of the arsine adduct via crystallographic analysis. [ABSTRACT FROM AUTHOR]

A chiral phosphine auxiliary was generated with excellent ee via catalytic asymmetric hydrophosphination of 3-(naphthalen-1-ylmethylene)pentane-2,4-dione. The subsequent metal complexation of the monophosphine yielded two different coordination complexes depending on the reaction conditions. The ortho-palladation of both coordination complexes resulted in the formation of a single dimeric phosphapalladacycle complex that could be further converted to the monomeric bisacetonitrile derivative. Moreover, the palladium complex exhibits interesting oxophilicity as the stable bisaquo derivative could be isolated and characterized crystallographically. The catalytic potential of the phosphapalladacycle was also demonstrated. [ABSTRACT FROM AUTHOR]

Single crystals of two new charge-transfer compounds, anthracene-F4TCNQ and tetracene-F4TCNQ, were grown by physical vapor transport. Both of these crystals have a 1 : 1 donor : acceptor stoichiometry and mixed stacking structure. The charge-transfer degrees at room temperature are estimated to be 0.051–0.089e and 0.086–0.148e for anthracene-F4TCNQ and tetracene-F4TCNQ, respectively. The C≡N stretching frequency depends linearly on the charge-transfer degree. A single-crystal field-effect transistor made from tetracene-F4TCNQ has average and maximum mobilities of ∼10−4 cm2 V−1 s−1 and 0.006 cm2 V−1 s−1, respectively, and an on/off ratio of ∼105. The tetracene-F4TCNQ charge-transfer single crystals exhibit good photoresponse and on–off switching. [ABSTRACT FROM AUTHOR]

A growing number of halogenated organic compounds have been identified as hazardous pollutants. Although numerous advanced oxidative processes have been developed to degrade organohalide compounds, reductive and nucleophilic molecular approaches to dehalogenate organic compounds have rarely been reported. In this manuscript, we employ nickel(ii)-ate complexes bearing the o-phenylenebis(N-methyloxamide) (Me2opba) tetraanionic ligand as nucleophilic reagents that can react with alkyl halides (methyl up to the bulky isobutyl) by O-alkylation to give their respective imidate products. Four new nickel(ii) complexes have been characterized by X-ray crystallography, and the salient structural parameters and FT-IR vibrational bands (∼1655 cm−1) concur with their assignment as the imidate tautomeric form. To the best of our knowledge, this is the first report on the nucleophilic reactivity of NiII(Me2opba) with halogenated organic compounds. The parent nickel(ii) Me2opba complex exhibits reversible electrochemical oxidation and reduction behavior. As a proof of concept, NiII(Me2opba) and its alkylated congeners were utilized for the electrocatalytic reduction of chloroform, as a representative, simple polyhalogenated organic molecule that could arise from the oxidative treatment of organic compounds by chlorination. Modest turnover numbers of up to 6 were recorded, with dichloromethane identified as one of the possible products. Future efforts are directed towards bulkier -ate complexes that possess metal-centered instead of ligand-centered nucleophilic activity to create more effective electrocatalysts for the reduction of halogenated organic compounds. [ABSTRACT FROM AUTHOR]

Cyclopalladation of the pyridyl-substituted chiral phosphine sulfide (N–P=S) and oxide (N–P=O) compounds afforded the asymmetric N–C(sp3)*–S and N–C(sp3)*–O pincer complexes. When applied as catalysts in asymmetric hydrophosphination, the newly developed aliphatic pincer catalyst could be recycled over three runs and obtained in large quantities via a one-pot “self-breeding” catalytic protocol. [ABSTRACT FROM AUTHOR]

The reaction of germylone (L)Ge (1) [L = 3-Ad-1-{C(tBu) = N(Mes)}C3H4N2] with 1 equivalent of MeOTf afforded a germyliumylidene ion [(L)GeMe]+OTf− (2), while reactions with M(CO)5(thf) (M = Cr, Mo, W) gave the corresponding germylone-metal complexes [(L)Ge]M(CO)5 (3–5). The former possesses a pyramidal Ge center, whereas the latter display a planar geometry around the Ge atom. Computational studies showed a unique bonding interaction between 1 and the M(CO)5 unit, which involves a σ-donation as well as a weak π-back-donation. [ABSTRACT FROM AUTHOR]

A simple and facile one-step method for the synthesis of an organic dye-functionalized polyoxometalate (POM) hybrid with visible-light photo-response was reported. The POM hybrid was fully characterized via single crystal XRD, powder XRD, FTIR and elemental analysis. The reaction of the organic dye with inorganic salts gave the dye-functionalized POM (MoBB3), in which the POM cluster was formed in situ. The electronic absorption peak of this hybrid was successfully extended beyond 680 nm. Photoelectrochemical measurement indicated that MoBB3 was photoresponsive under visible-light illumination, suggesting that it is an n-type (electron conductive) semiconducting material. This result might offer a method for the design of novel organic dye-functionalized POMs for photoelectric applications. [ABSTRACT FROM AUTHOR]

Gold-catalyzed hydroimination of terminal alkynes, giving rise to anti-Markovnikov adducts concomitant with unstable Markovnikov adducts is described. The elementary step can be applied for the construction of pyridine derivatives from ammonia and alkynes. [ABSTRACT FROM AUTHOR]

Herein, we discover the new reactivity of the 1,3,5-triazine moiety reacting with a phenol group and report the development of biocompatible and catalyst-free triazine-pyridine chemistry (TPC) for tyrosine labelling under physiological conditions and profiling in the whole proteome. TPC exhibited high tyrosine chemoselectivity in biological systems after cysteine blocking, displayed potential in tyrosine-guided protein labelling, and had bio-compatibility in live cells. [ABSTRACT FROM AUTHOR]

Natural laccase exhibits a broad substrate scope and only water is a by-product of its action, making it an environmentally friendly enzyme. It has good application prospects in food engineering, paper making, textiles, environmental pollutant treatment, and biosensing. However, natural laccase often has inherent defects like a high price, poor stability, and difficulty of being recycled. Nanomaterials with laccase-like activity have been rapidly developed in recent years to overcome these drawbacks. In comparison with laccase, nanozymes possess the benefits of being low price, mass-produced, having long-term storage, high stability, and adjustable activity. This review first briefly introduces the catalytic mechanism and the application of laccase, hoping to stimulate future research ideas for laccase mimics and expand its application fields. Then, nanomaterials with laccase activity are reviewed, and their application directions are introduced. Finally, it summarizes the current challenges of laccase-mimicking enzymes and proposes the development direction of future research. [ABSTRACT FROM AUTHOR]

Sensitive and efficient monitoring of food-borne bacteria is of great importance for food safety control. Herein, a novel biosensor for highly sensitive detection of Staphylococcus aureus (S. aureus) was constructed by combining hybridization chain reaction (HCR) and nicking enzyme. Different from the upstream-downstream based circuit, the proposed biosensor integrated HCR circuit and three-way DNA junction nicking enzyme assisted signal amplification (3WJ-NEASA) into a virtuous circle of promotion. In the HCR-mediated 3WJ-NEASA sensing strategy, target DNA of S. aureus initiated the self-assembly between HCR hairpins (H1 and H2), which exposed the gap to capture molecular beacon (MB) and construct the 3WJ structure. Meanwhile, MB increased the stability of HCR nanowires and enhanced the efficiency of the HCR circuit, and thus more 3WJ-NEASA circuits were generated in HCR nanowires. Benefiting from the synergistic amplification coupling HCR and 3WJ-NEASA, this isothermal biosensor can detect as low as 6.7 pM of target DNA in one step within only 30 min. Furthermore, the HCR-mediated 3WJ-NEASA assay has been applied in the detection of S. aureus with a limit of detection (LOD) as low as 1.2 × 101 cfu mL−1, and has exhibited reliable practicability in spiked milk. It is the first time that a DNA biosensor combining HCR and 3WJ-NEASA for dual signal amplification was developed and has been adopted to the sensitive analysis of food-borne bacteria. Additionally, this strategy can serve as a universal platform for monitoring other analytes, and therefore possesses broad application prospects in food safety and environmental monitoring. [ABSTRACT FROM AUTHOR]

Bisphosphine oxides formed highly active asymmetric Heck catalysts, which were applied in asymmetric synthesis of pharmacologically active azacycles. Olefin insertion proceeded via cis pathways, different from P,N-ligands. [ABSTRACT FROM AUTHOR]

There are many active pharmaceutical ingredients that lack N–H, O–H and S–H hydrogen-bond donor functional groups. N,N-Disubstituted O-thiocarbamates are examples of molecules that display such a feature. Despite the desirable medicinal properties displayed by some N,N-disubstituted O-thiocarbamates, the study of the solid-state properties of these compounds has been relatively unexplored. Herein, we report the synthesis and analysis of the structures and properties of a series of N,N-dimethyl-O-thiocarbamates, and use X-ray diffraction techniques to gain insight into how these molecules self-assemble in the solid-state. As part of our work, we report for the first time the crystal structure of tolnaftate, an active pharmaceutical ingredient that is indicated for the treatment of fungal infections. It was observed that the aryl-thiocarbamate C–O bonds are twisted such that the planar aryl and carbamate moieties are orthogonal. Such a non-planar molecular geometry affects the way the molecules pack and crystal structure analyses revealed four general modes in which the molecules can assemble in the solid-state, with some members of the series displaying isostructural relationships. Computational modelling of the cohesive energy densities in the crystals suggests that there is no single stacking type that is associated with greater stability. However, crystals with a combination of high packing index and π⋯π stacking interactions appear to display large cohesive energy densities. The lack of strong hydrogen bonding interactions in the crystals also leads to relatively low Young's moduli that are within a narrow range of 10–15 GPa for all 14 crystal structures reported. [ABSTRACT FROM AUTHOR]

Modulated synthesis and isoreticular expansion of Th-MOFs enable the stepwise construction of hierarchical complexes in which porosity and functionality can be fine-tuned, affording new Th-MOFs with a record high void space (74.0%), the largest surface area (3396.5 m2 g−1) among thorium materials, and excellent adsorption capacities toward radioactive iodine. [ABSTRACT FROM AUTHOR]

In this study, a series of Pickering emulsions for catalysis of Knoevenagel condensations of malononitrile with aldehydes were prepared by surface modification of amine-functionalized graphene oxide (GO-NH2) with trimethoxymethylsilane (MTMS). The catalytic activity of the prepared Pickering emulsion system in a Knoevenagel condensation was mainly determined by the active sites and properties (namely droplet size, density, and distribution) of the emulsion. The results show that the mass ratio of 3-aminopropyltrimethoxysilane to MTMS affects the active catalytic sites and properties of the Pickering emulsion. Under conditions that provided a large number of active catalytic sites in the Pickering emulsion, modification of the surface of amine-functionalized GO with an organosilane enhanced substrate adsorption on the catalyst and improved the properties of water-in-oil Pickering emulsions. This increased the Picking emulsion catalytic activity. The Pickering emulsion prepared with GO-NH2 : Si = 1.8 : 0.2 gave the highest catalytic activity in a Knoevenagel condensation at 40 °C, and its activity was much higher than that of GO-NH2. The Pickering emulsion with GO-NH2(1.8)–Si(0.2) still showed high catalytic activity after six cycles and therefore has good reusability. [ABSTRACT FROM AUTHOR]

A sensitive sandwich immunoassay for the sensing of human epididymis protein 4 (HE4) is developed based on aggregation-induced emission probe doped silica nanoparticles. Fluorescent silica nanoparticles (TSiO2) with excellent performance were prepared using a tetraphenylethylene based probe (TPE-C4-4) to produce a controlled aggregation effect, and HE4 was detected using antibody-functionalized fluorescent silica nanoparticles. The fluorescent silica nanoparticles possess good photophysical properties. The TSiO2 NPs were surface modified with carboxyl groups, and the antibody was covalently attached onto the surface of the nanoparticles. In addition, magnetic beads were modified with N-hydroxysulfosuccinimide sodium salt (NHS) on their surface, capable of forming stable peptide bonds with the antibody. TSiO2 NPs modified by an antibody and the magnetic beads modified by an antibody were used for the sandwich immunoassay for HE4 protein. The assay is quite sensitive and selective. The detection limit of HE4 is estimated to be 40 pM. The assay shows promising applications for the early diagnosis of ovarian cancer and the development of ovarian cancer-related drugs. [ABSTRACT FROM AUTHOR]

A simple nanopore modification and sensing strategy was developed for the detection of miRNAs. This preparation and sensing approach provides a quick, simple and facile tool for the detection of specific biomolecules with high sensitivity and selectivity, and may find a wide range of applications in bio-analysis. [ABSTRACT FROM AUTHOR]

The fabrication of a perovskite oxide with a tunable pore-size was implemented by a general inorganic salt-template strategy. As a proof-of-concept, hierarchically porous PrBa0.5Sr0.5Co1.5-Fe0.5O5+δ (PBSCF) with a surface area of 148 m2 g−1 was successfully prepared, which exhibited remarkable electrocatalytic performance for the oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

Treatment of tetrakis(dimethylamino)diboron (B2(NMe2)4) with 1,4-bis(2-(triisopropylsilyl)ethynyl)naphthalene-2,3-diamine (1) generated a large NBBN polycyclic compound 1,1-B2{2,3-(NH)2-1,4-(iPr3SiC2)2C10H4} (2). The X-ray structure analysis reveals that 2 has a twisted structure (dihedral angle ≈ 21.75°) with a rather short B–B bond (1.667(9) Å). Theoretical calculations on 1,1-B2 isomer 2 and its counterpart 1,2-B2 isomer 3 have been conducted to understand their frontier orbital energy levels. Compound 2 shows strong emission with a high quantum yield of 0.52, despite the presence of many unbeneficial non-radiative behaviors such as the vibration of the TIPS groups and the rotation of the B–B single bond. [ABSTRACT FROM AUTHOR]

In this work, a label-free electrochemical apta-nanosensor was fabricated on a single gold nanodisk electrode (AuNDE) for thrombin sensing with high sensitivity via a novel signal amplification strategy. This recognition platform was fabricated via self-assembly of helper DNA (HP-DNA), thrombin-binding aptamer (TBA) and gold nanoparticle (AuNP)-DNA complexes to form a sandwich structure on the AuNDE surface. A novel signal amplification strategy via designed AuNP-DNA complexes was introduced using Ru(NH3)63+ as the signal reporter based on the electrostatic interaction. In the presence of thrombin, the strong interaction between the TBA and target led to the dissociation of sandwich DNA complexes from the AuNDE, which resulted in the reduction current of Ru(NH3)63+. This proposed sensing platform showed a wide detection range of 0.1 pM–5 nM and a low detection limit of 0.02 pM. Considering the small overall dimensions and high sensitivity, this nanosensor can be potentially applied for bioanalysis in living biosystems. [ABSTRACT FROM AUTHOR]

An ultrafine ruthenium nanocrystal (RuNC) was fabricated via thermal annealing tris(2,2′-bipyridine)ruthenium dichloride with cyanuric acid. The as-obtained RuNC features a small diameter of ∼2 nm and high crystallinity. As an electrocatalyst for the hydrogen evolution reaction, the ultrafine RuNC exhibited remarkable performance in both acidic and alkaline media. [ABSTRACT FROM AUTHOR]

The iridation of (R)-N,N-dimethyl-1-(1-naphthyl)ethylamine in the presence of a base afforded an assortment of products ranging from organic molecules to coordinated systems and cyclometalated complexes. The transformation affirmed the postulation where steric effects within the coordination sphere favor a β-hydride elimination-like decomposition pathway, competing alongside ortho-metalation, thus leading to iminium intermediates. The same procedure also generated an unprecedented carbocyclic η1,η2-cycloiridated species that could not be attained from the direct cyclometalation of its organic ligand. [ABSTRACT FROM AUTHOR]

Mechanochemistry has been established to be an environmentally-friendly way of conducting reactions in a solvent-free manner. The development of mechanochemical orthogonal reactions, in which multiple reagents are milled together, can be a powerful strategy to selectively yield the desired product. Such orthogonal syntheses are rare, especially those involving main group frameworks – based on bonds other than carbon – which are yet to be reported. Herein, we demonstrate the direct formation of air- and moisture-stable cyclophosph(v)azanes enabled by an orthogonal “one-step one-pot” mechanochemical reaction. In addition, detailed hydrolytic- and air-stability studies, conducted over one and 12 months, respectively, revealed high robustness of these compounds. [ABSTRACT FROM AUTHOR]

A new fluorine–boron compound BOPHY-PTZ was designed and synthesized. The fluorescent dye was used as a highly sensitive probe for Cu2+ ion detection. The mechanism of detection involved Cu2+ ion oxidation of the phenothiazine (PTZ) moiety and blocked the intramolecular charge transfer (ICT) process from the electron-donating PTZ moiety to the electron-accepting BOPHY moiety. BOPHY-PTZ showed a weak fluorescence in solution. However, it displayed a strong fluorescence signal enhancement upon the addition of Cu2+ ions, and 1.0 nM concentration of Cu2+ can be clearly detected. The assay is simple, sensitive and convenient, and it exhibits excellent selectivity for Cu2+ ions over the other metal ions. The BOPHY-PTZ probe could be used for Cu2+ ion detection in practical samples and for environmental monitoring related applications. [ABSTRACT FROM AUTHOR]

The impact of the structural attributes of chiral PC- and PCP-palladium catalysts was investigated in the asymmetric hydrophosphination of various heterocycle-functionalized enone substrates. Due to the architecture of the catalysts, they are confronted with potential catalyst deactivation arising from the coordination of the electron-rich heteroatoms (P, O, N and S) to the metal center. A systematic variation of the location and identity of the heteroatoms demonstrated the impact of structural modifications on the substrates, which have a significant influence on both yields (16–99%) and enantioselectivities (0–99%). A detailed discussion on the distinct catalytic mechanisms (intra- vs. inter-molecular addition) provides important information to explain the results obtained. [ABSTRACT FROM AUTHOR]

Here, we present our recent progress on the synthesis, crystal structure, physical properties and DFT calculations of a novel large pyrene-fused N-heteroacene (15RINGS) with 15 aromatic six-membered rings linearly fused in one row. The long conjugated backbone (more than 35 Å) of 15RINGS possesses a dual-bending feature (the bending angle is about 13.2°). [ABSTRACT FROM AUTHOR]

The coordination chemistry of an amidinato silylene and germylene toward group 14 element(ii) halides is described. The reaction of the amidinato silicon(ii) amide [LSiN(SiMe3)2] (1, L = PhC(NtBu)2) with SnCl2 and PbBr2 afforded the amidinato silylene–dichlorostannylene and –dibromoplumbylene adducts [L{(Me3Si)2N}SiEX2] (E = Sn, X = Cl (2); E = Pb, X = Br (3)), respectively, in which there is a lone pair of electrons on the Sn(ii) and Pb(ii) atoms. X-ray crystallography, NMR spectroscopy and theoretical studies show conclusively that the Si(ii)–E(ii) bonds are donor–acceptor interactions. Similar electronic structures were found in the amidinato germylene–dichlorogermylene and –dichlorostannylene adducts [L{(Me3Si)2N}GeECl2] (E = Ge (5), Sn (6)), which were prepared by treatment of the amidinato germanium(ii) amide [LGeN(SiMe3)2] (4) with GeCl2·dioxane and SnCl2, respectively. [ABSTRACT FROM AUTHOR]

Single Au nanowire electrodes and single Pt@Au nanowire electrodes showed steady-state voltammetric responses and a fast electron-transfer rate, which have been used to fabricate an E-DNA sensor and investigate the oxygen reduction reaction at the single nanowire level. [ABSTRACT FROM AUTHOR]

The impact of the structural attributes of chiral PC- and PCP-palladium catalysts was investigated in the asymmetric hydrophosphination of various heterocycle-functionalized enone substrates. Due to the architecture of the catalysts, they are confronted with potential catalyst deactivation arising from the coordination of the electron-rich heteroatoms (P, O, N and S) to the metal center. A systematic variation of the location and identity of the heteroatoms demonstrated the impact of structural modifications on the substrates, which have a significant influence on both yields (16–99%) and enantioselectivities (0–99%). A detailed discussion on the distinct catalytic mechanisms (intra- vs. inter-molecular addition) provides important information to explain the results obtained. [ABSTRACT FROM AUTHOR]

A 13C{1H} NMR based investigation was conducted to examine the electronic properties of C(aryl)–M bonds and their trans influence in P–C(aryl)–P pincer complexes. A series of structurally related platinum pincer complexes were rationally designed and their corresponding 13C–195Pt coupling constants were systematically examined. By methodical substitution of the ligand trans to the organometallic C(aryl)–Pt bond, this study revealed the significant influence of the ligands on the nature of the C(aryl)–M bonds. The single crystal X-ray analysis of the complexes and computational studies further confirmed the observations that the C–M bond exhibits significant π-character. [ABSTRACT FROM AUTHOR]

A novel fluorescence turn-on strategy based on Au nanoparticles and a perylene probe for the sensing of Hg2+ ions has been developed. It was observed that a perylene probe could be adsorbed onto the surface of Au NPs through strong electrostatic and hydrophobic interactions. Its fluorescence was efficiently quenched by the Au nanoparticles. However, in the presence of Hg2+ and NaBH4, Hg2+ was reduced and an Au/Hg amalgam was formed on the surface of the Au nanoparticles. The perylene probe could hardly be adsorbed and quenched by the Au/Hg amalgam. A turn on fluorescence signal was therefore detected. The assay is quite sensitive, and 5 nM Hg2+ could be easily detected. It is also very selective, a number of metal ions were tested and no noticeable interference was observed. The assay was also successfully applied for the determination of Hg2+ in lake water samples. A simple, fast, inexpensive, highly sensitive and selective Hg2+ sensing strategy is therefore established. [ABSTRACT FROM AUTHOR]

The regioselective asymmetric hydrophosphination of pyridine-functionalized alkenes can be achieved in the presence of stoichiometric amounts of the chiral palladium complex (R)-1. The presence or absence of base affords the respective β- and α-adducts with excellent regiocontrol. Chiral gold–phosphine complexes incorporating the adducts exhibited good in vitro anticancer activity against the breast cancer cell line MDA-MB-231. Selectivity between the cancer cell line and normal cells was also observed. [ABSTRACT FROM AUTHOR]

Here, we report on a surfactant-thermal method to prepare four new 3-D crystalline heterometal–organic frameworks (HMOFs). The results indicate that our new strategy for growing crystalline materials in surfactant media has great potential for the synthesis of novel MOFs with various structures. [ABSTRACT FROM AUTHOR]

A new approach for the sensitive and selective sensing of a protein has been developed. Cytochrome c could quench the fluorescence of a fluorophore labeled aptamer efficiently. The specific binding between the aptamer and the target protein resulted in a turn-on emission signal, which could be used for protein quantification. [ABSTRACT FROM AUTHOR]

Optically pure P-chiral 1,2- and 1,3-diphosphines were synthesized chemoselectively and stereoselectively from the chiral organopalladium complex promoted asymmetric Diels–Alder reaction between 3,4-dimethyl-1-phenylphosphole (DMPP) and cis- and trans-ester substituted allylic phosphines. [ABSTRACT FROM AUTHOR]