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Zinc sulfide (ZnS) is a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity, abundance, cost-effectiveness, and environmental friendliness. Herein, a hydrangea-like ZnS-carbon composite (ZnS-NC) is synthesized through the hydrothermal method and subsequent pyrolysis of a supramolecular precursor guanosine. The resulting composite comprises ultrafine ZnS nanoparticles firmly stabilized on a nitrogen-doped carbon matrix, featuring mesoporous channels and high surface areas. When utilized as an anode material for LIBs, the initial discharge specific capacity of the ZnS-NC electrode reaches an impressive value of 944 mA h g−1 at 1.0 A g−1, and even after 450 cycles, it maintains a reversible capacity of 597 mA h g−1. Compared with pure ZnS, the ZnS-NC composite exhibits significantly improved rate performance and cycling stability. This enhancement in Li-storage performance can be attributed to a synergistic effect within the ZnS-NC composite, which arises from the large exposed active site area, efficient ion/electron transfer, and strong interaction between the ZnS nanoparticles and the carbon framework. Overall, this work presents an eco-friendly approach for developing metal sulfide-carbon composites with exceptional potential for energy storage applications. [ABSTRACT FROM AUTHOR]

Microbes are usually present as a specific microbiota, and their classification remains a challenge. MALDI-TOF MS is particularly successful in library-based microbial identification at the species level as it analyzes the molecular weight of peptides and ribosomal proteins. FT-IR allows more accurate classification of bacteria at the subspecies level due to the high sensitivity, specificity and repeatability of FT-IR signals from bacteria, which is not achievable with MALDI-TOF MS. Previous studies have shown that more accurate identification results can be obtained by the fusion of FT-IR and MALDI-TOF MS spectral data. Here, we constructed 20 groups of model microbiota samples and used FT-IR, MALDI-TOF MS, and their fusion data to classify them. Hierarchical clustering analysis (HCA) showed that the classification accuracy of FT-IR, MALDI-TOF MS, and the fusion data was 85%, 90%, and 100%, respectively. These results indicate that both FT-IR and MALDI-TOF MS can effectively classify specific microbiota, and the fusion of their spectral data could improve the classification accuracy. The FT-IR and MALDI-TOF MS data fusion strategy may be a promising technology for specific microbiota classification. [ABSTRACT FROM AUTHOR]

Macrocyclic arenes including calixarenes, resorcinarenes, cyclotriveratrylene, pillararenes and so on have emerged as highly attractive synthetic macrocyclic hosts due to their unique structures, facile functionalization, and broad range of applications. In recent years, there has been growing interest in the development of novel macrocyclic arenes composed of various aromatic building blocks bridged by methylene groups, which have found applications in various research areas. Consequently, the development of novel macrocyclic arenes has become a frontier and hot topic in supramolecular and macrocyclic chemistry. In this review, we feature the recent advances in the synthesis and applications of novel macrocyclic arenes that have emerged in the last decade. The general synthetic strategies employed for these macrocyclic arenes are systematically summarized, and their wide applications in molecular recognition and assemblies, molecular machines, biomedical science and functional materials are highlighted. [ABSTRACT FROM AUTHOR]

[{SiNDipp}MgNa]2 ({SiNDipp} = {CH2SiMe2N(Dipp)}2; Dipp = 2,6-i-Pr2C6H3) reacts directly with H2 to provide a heterobimetallic hydride. Although the transformation is complicated by the simultaneous disproportionation of magnesium, computational density functional theory (DFT) studies suggest that this reactivity is initiated by orbitally-constrained and interactions between the frontier MOs of both H2 and the tetrametallic core of [{SiNDipp}MgNa]2. [ABSTRACT FROM AUTHOR]

Triethylamine promoted cycloaddition reaction of phenacylmalononitriles and o-hydroxychalcones in ethanol at room temperature gave multifunctionalized cyclopent-3-ene-1-carboxamides in good yields and with high diastereoselectivity. More importantly, the similar reaction of phenacylmalononitriles and chalcone o-enolates in ethanol at room temperature afforded functionalized 2-oxabicyclo[2.2.1]heptane derivatives in satisfactory yields and with high diastereoselectivity. A rational domino reaction was tentatively proposed to explain the selective formation of different cyclic compounds and the diastereoselectivity of the reaction. [ABSTRACT FROM AUTHOR]

Intermolecular hydrogen bonds play an important role in the carboxymethyl chitosan/sodium alginate (CMCS/SA) composite spinning solution and composite fiber. In this study, we prepared a CMCS/SA composite fiber with various intermolecular hydrogen bonding (inter-MHB) proportions via a physical blending method. First, we studied quantitatively the effect of the inter-MHB proportions on the rheological property of the spinning solution and microstructure of the composite fiber. The apparent viscosity of the CMCS/SA composite solution decreased with the increase in the shear rate; however, it increased with the increase in the inter-MHB proportion. The crystallinity and surface roughness of the CMCS/SA composite fibers decreased with the inter-MHB proportion rising, as characterized by XRD and SEM analyses. Furthermore, we quantitatively constructed the relationship between the inter-MHB proportions and the performance of the CMCS/SA composite fibers. As the inter-MHB proportion increased, the tensile strength and modulus of the CMCS/SA composite fibers were enhanced significantly; the thermal stability of the CMCS/SA composite fibers was also improved slightly, as characterized by TGA; the hydrophilicity of the CMCS/SA composite fibers decreased slightly, as characterized by the contact angle test. Therefore, we can improve the viscosity, tensile strength, crystallization, thermal decomposition temperature, and hygroscopicity of CMCS/SA composite fibers by quantitatively regulating the inter-MHB proportions. This work also provides a theoretical and application basis for the study of related composite systems and fibers. [ABSTRACT FROM AUTHOR]

The reactivity of a seven-membered cyclic potassium diamidoalumanyl toward a variety of ketone small molecules has been assessed. Whilst acetophenone generates an aluminium pinacolate derivative, reductive C–C coupling is induced between the ketyl and ortho-carbon centres of two equivalents of benzophenone. In contrast, whereas oxidative addition of an enolisable proton is observed with 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone undergoes an unprecedented hydroalumination process, where the reducing hydride may be traced to intramolecular oxidative addition of a (sp3)C–H bond. [ABSTRACT FROM AUTHOR]

Reactions of the seven-membered heterocyclic potassium diamidoalumanyl, [K{Al(SiNDipp)}]2 (SiNDipp = {CH2SiMe2NDipp}2; Dipp = 2,6-di-isopropylphenyl), with a variety of Cu(I), Ag(I) and Au(I) chloride N-heterocyclic carbene (NHC) adducts are described. The resultant group 11-Al bonded derivatives have been characterised in solution by NMR spectroscopy and, in the case of [{SiNDipp}Al–Au(NHCiPr)] (NHCiPr = N,N′-di-isopropyl-4,5-dimethyl-2-ylidene), by single crystal X-ray diffraction. Although similar reactions of LAgCl and LAuCl, where L is a more basic cyclic alkyl amino carbene (CAAC), generally resulted in reduction of the group 11 cations to the base metals, X-ray analysis of [(CyCAAC)AgAl(SiNDipp)] (CyCAAC = 2-[2,6-bis(1-methylethyl)phenyl]-3,3-dimethyl-2-azaspiro[4.5]dec-1-ylidene) provides the first solid-state authentication of an Ag–Al σ bond. The reactivity of the NHC-supported Cu, Ag and Au alumanyl derivatives was assayed with the isoelectronic unsaturated small molecules, N,N′-di-isopropylcarbodiimide and CO2. While these reactions generally provided products consistent with nucleophilic attack of the group 11 atom at the electrophilic heteroallene carbon centre, treatment of the NHC-supported copper and silver alumanyls with N,N′-di-isopropylcarbodiimide yielded less symmetric Cu–C and Ag–C-bonded isomers. In contrast to the previously described copper and silver alumanyl derivatives, [(NON)Al(O2C)M(Pt-Bu3)] (M = Cu or Ag; NON = 4,5-bis(2,6-di-isopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), which were prone to facile CO extrusion and formation of carbonate derivatives, the NHC-supported dioxocarbene species, [(NHCiPr)M(CO2)Al(SiNDipp)] (M = Cu, Ag, Au), are all stable at room and moderately elevated temperatures. The stabilising role of the NHC co-ligand was, thus, assessed by preparation of the t-Bu3P adducted copper-alumanyl, [(t-Bu3P)CuAl(SiNDipp)]. Treatment of this latter compound, which was also structurally characterised by X-ray analysis, with both N,N′-di-isopropylcarbodiimide and CO2 again provided smooth heteroallene insertion and formation of the relevant Cu–C-bonded products. Although both compounds were quite stable at room temperature, heating of [(t-Bu3P)Cu(CO2)Al(SiNDipp)] at 60 °C induced elimination of CO and formation of the analogous carbonate, [(t-Bu3P)Cu(OCO2)Al(SiNDipp)], which was identified by 13C and 31P NMR spectroscopy. Reflective of the more reliable nucleophilic behaviour of the gold centres in these group 11 alumanyls, computational (QTAIM and NBO) analysis highlighted a lower level of covalency of the Al–Au linkage in comparison to the analogous Al–Cu and Al–Ag interactions. Although substitution of the co-ligand significantly perturbs the charge distribution across the Cu–Al bond of [LCuAl(SiNDipp)] (L = NHCiPr or t-Bu3P), only a negligible difference is observed between the phosphine-coordinated copper systems derived from either the [SiNDipp]- or (NON)-based alumanyl ligands. Computational mapping of the reaction profiles arising from treatment of the various group 11 alumanyls with N,N′-di-isopropylcarbodiimide indicates that the observed formation of the Cu–N and Ag–N bound isomers do not provide the thermodynamic reaction outcome. In contrast, examination of the CO2-derived reactions, and their potential toward CO extrusion and subsequent carbonate formation, implies that the identity of the co-ligand exerts a greater influence on this aspect of reactivity than the architecture of the diamidoalumanyl anion. [ABSTRACT FROM AUTHOR]

Triple-stranded metallo-supramolecular helicates were readily constructed by achieving a coordination of the gallium(iii) cation by ligands based on 2,7- and 2,6-disubstituted triptycenes. The significance of these building blocks in the construction of helicates with the capability for guest encapsulation was also revealed. [ABSTRACT FROM AUTHOR]

The design and synthesis of crystalline materials have been a subject of intensive research because of their interesting structures, physicochemical properties, and potential applications. However, the crystalline structure of organic–inorganic hybrid materials collapses to lose the structural features of the original networks and/or frameworks when exposed to different stimuli such as pH, vapor, water, high temperature, and organic solvents. This hampers further studies focusing on practical applications. Although several review articles provide reasonable pathways for the preparation of stable metal–organic frameworks (MOFs) and coordination polymers (CPs), the synthesis and design of stable materials containing organic species remain challenging. In this frontier article, we discuss the development of crystalline MOF, CP, metallophosphate, and metallophosphite materials, and provide a feasible approach for the formation of stable organic–inorganic hybrid compounds that combine MOFs (or CPs) and phosphate (or phosphite) building elements. In addition to their interesting structures, the synthetic strategies and structural stabilities of such hybrid composites are also presented. [ABSTRACT FROM AUTHOR]

An exploratory study of the lead-tellurium-oxygen phase space led to two new compounds, Ba3PbTe6O16 (BPTO) and Na2Pb9(μ6-O)2(Te2O10)2 (NPTO), which were synthesized under hydrothermal conditions at 550 °C and 210 °C, respectively, and characterized by single-crystal X-ray diffraction, infrared and X-ray photoelectron spectroscopy. BPTO adopts a layer structure. The Te4+ cation in BPTO is bonded to four oxygen atoms at about 2.0 Å with two more oxygens at about 3.0 Å. The seesaw-shaped TeO4 units share corners to form 2D layers containing six-membered rings and the Ba2+ and Pb2+ cations are situated in the interlayer region. The structure of NPTO contains dimers of edge-sharing Te6+O6 octahedra, which are connected through five-coordinate Pb2+ cations. A unique six-coordinate O atom is at the center of the octahedron formed by five Pb2+ and one Na+ cations. BPTO is one of the few metal tellurites which were synthesized under supercritical hydrothermal reaction conditions. The Pb2+ cation in NPTO shows pronounced stereochemical effects of the lone electron pair. In contrast, BPTO shows no stereochemical evidence of the inert pair. [ABSTRACT FROM AUTHOR]

A new class of macrocyclic arenes, 3,6-fluoren[5]arenes, were conveniently synthesized in good yields by one-step reaction. The 3,6-fluoren[5]arenes had symmetric pentagon structures with big and rich-electron cavities, which made them form 1 : 1 complexes with fullerenes C60 and C70. The association constants of the complexes were all greater than 105 M−1. [ABSTRACT FROM AUTHOR]

Three series of copper hydride clusters [Cu8H6L6]2+ (1), [Cu4HX2L4]+ where X− = Cl− (2a), Br− (2b), I− (2c), N3− (2d) and SCN− (2e), and [Cu4HX3L3] where X− = Br− (3b) and I− (3c) (L = 2-(diphenylphosphino)pyridine, dppy) were synthesized and characterized by single-crystal X-Ray crystallography and standard spectroscopic techniques. The metal core of 1, Cu8, can be described as a bicapped octahedron, while those of 2 and 3 series adopt tetrahedral structures. The hydride positions were deduced from difference electron density maps and corroborated by NMR and DFT calculations. For 1, there are two μ4-H−, one each in the two tetrahedral cavities of the two capping atoms and four μ3-H− on the six triangular faces around the waist of the octahedron. For [Cu4HX2L4]+ and [Cu4HX3L3] series, the single μ4-H− resides in the center of the Cu4 tetrahedron. It was found that these three series of copper clusters are intimately connected and can convert from one to another under specific reaction conditions. Their transformation pathways were investigated in detail. Spontaneous resolution to form optically pure enantiomeric single crystals was observed for [Cu4H(SCN)2L4]+ (2e) and [Cu4HBr3L3] (3b). Photoluminescence was observed for [Cu4HX2L4]+, as well as [Cu4HX3L3] with strong emissions from green to yellow regions. [ABSTRACT FROM AUTHOR]

UiO-66 and its modified forms (UiO-66-NH2 and UiO-66-OH) were used as supports to prepare Rh–Mn catalysts by using a co-impregnation method, and their catalytic activities were investigated for the direct synthesis of ethanol-based C2+ oxygenates from CO hydrogenation. The catalysts were comprehensively characterized using N2 sorption, XRD, XPS, DRIFT, and TPSR analyses. The structural and textural properties of the catalysts clearly show that Rh and Mn are highly dispersed in the pores of MOFs, but the order of the original structure is partially sacrificed due to the loading of metals and the synergistic effect of Rh, Mn, and Zr would be influenced by various functional groups present in UiO-66. On combining both in situ FT-IR and TPSR analyses, it is confirmed that the higher number of active sites of Rh0 on RM/UiO-66 promotes the CO dissociation ability and hydrogenation rate, which result in its best catalytic activity with the highest yield of C2+ oxygenates, 197.3 g (kg h)−1. [ABSTRACT FROM AUTHOR]

Development of circularly polarized luminescence (CPL) materials utilizing supramolecular strategies has recently attracted increasing interest in supramolecular chemistry and materials science. Chiral macrocycles, especially chiral macrocyclic hosts, have stable structures, adjustable internal cavities to encapsulate different guests, and host–guest complexation to induce special photophysical properties. Consequently, various CPL materials based on chiral macrocycles have been developed during the last decade. To gain a better understanding of this rapidly developing research area, it is necessary and also important to summarize the advances in CPL materials based on chiral macrocycles. In this review, CPL materials from different chiral macrocycles, especially classical and newly reported chiral macrocyclic hosts and their derivatives, will be comprehensively summarized. It is believed that this review will be of guiding significance and also very helpful for the development of macrocyclic chemistry and CPL materials. [ABSTRACT FROM AUTHOR]

By condensation reactions of pillar[5]arene derivatives and alkylenediamines with different lengths of alkyl chains, self-locked dipillar[5]arene-based pseudo[1]rotaxanes and bispseudo[1]-rotaxanes were obtained, which were characterized via 1D NMR, 2D NMR, and X-ray analyses. It was found that the lengths of alkyl chains of alkylenediamines played crucial roles in forming these self-locked molecules. [ABSTRACT FROM AUTHOR]

Facile synthesis and postsynthetic modification of a rectangular 1,2,4-triazole-based NHC macrocycle have been developed. The silver complex [Ag2(1)2](BF4)2 is derived from the corresponding triazole salt H2-1(BF4)2 upon reaction with Ag2O. The structure of the metallocyclic Ag–NHC complex [Ag2(1)2](BF4)2 was determined by single-crystal X-ray diffraction analysis. The metal–carbene template undergoes photodimerisation of its terminal cinnamic esters (UV irradiation, λ = 365 nm) and generates a macrocyclic tetra (NHC) ligand. The desired tetra-1,2,4-triazole macrocycle was isolated in good yield by eliminating the metal ions from the photodimerisation product. All complexes were fully characterized by multinuclear NMR measurements (1H, 13C{1H}, COSY, HSQC and HMBC) and ESI mass spectroscopy. [ABSTRACT FROM AUTHOR]

Complexation between a triptycene-derived macrotricyclic host and paraquat derivative and different polycyclic aromatic hydrocarbons in the solid state was investigated in detail. It was found that through multiple π–π, C–H…π and C–H…O hydrogen bonding interactions, four new kinds of quaternary complexes with “Russian doll”-like capsule structures in different complexation modes can be obtained. Furthermore, the complexes could self-assemble into linear supramolecular arrays, and 2D grid-like structures. [ABSTRACT FROM AUTHOR]

N-doped Si nanoparticles were prepared synchronously by nitridation of Mg2Si. The existence of nitrogen doping can be demonstrated by the XPS spectrum and EELS energy-filtered images. When the N-doped Si nanoparticles were used as an anode for Li-ion batteries, a high reversible capacity of 2595 mA h g−1 at 0.36 A g−1 after 40 cycles, and 805 mA h g−1 at 3.6 A g−1 after 800 cycles could be obtained. [ABSTRACT FROM AUTHOR]

A new acid/base controllable host–guest system based on a triptycene-derived macrotricyclic host and protonated 4,4′-bipyridinium/pyridinium salts was developed. Moreover, the competition complexation process between the host and two different kinds of 4,4′-bipyridinium salts could also be chemically controlled by acid and base. [ABSTRACT FROM AUTHOR]

As a green adhesive, lignin-based acrylate adhesives have a promising future in substitute commercial adhesives owing to their cost-effectiveness, and environmental friendliness. In this work, a green and convenient strategy for the fabrication of lignin-based acrylate adhesives was developed via the introduction of lauryl methacrylate with a low glass transition temperature (−62 °C) into the chemical structure of lignin to improve the compatibility, toughness, strength and wettability of lignin-based adhesives. With the introduction of lauryl methacrylate, the shear strength of the lignin-based adhesive reached 5.10 MPa, which is 114% higher than the traditional acrylate adhesive. Moreover, the lignin-based adhesive also exhibits excellent hydrophobicity and high shear strength after 12 h of immersion in water. This work not only provides a new strategy for the fabrication of economical, green, and sustainable lignin-based acrylate adhesives without the participation of organic solvents, but also achieves the value-added utilization of lignin. [ABSTRACT FROM AUTHOR]

A pair of inherently chiral belt-shaped conjugated macrocycles were conveniently synthesized starting from 2,7-fluoren[3]arene triflate, and they not only exhibited green fluorescence, but also showed circularly polarized luminescence with a ‖glum‖ of 2.0 × 10−3. [ABSTRACT FROM AUTHOR]

Aiming to tackle the problems of low classification accuracy, difficult data processing, long analysis time, and the influence of subjective consciousness of traditional Baijiu (Chinese liquor), this paper reports a method based on the combination of laser-induced breakdown spectroscopy with high-frequency ultrasonic atomization system (AS-LIBS) and optimized grid search cross validation (Opt-GSCV) for high-precision and rapid classification of Baijiu of different dimensions. Multi-dimensional high-precision classification of 23 Baijiu samples with different series, degrees, and production dates from Shanxi Xinghuacun Fen Wine Factory Co., Ltd was performed. By studying the growth and evolution mechanism of plasma generated by laser excitation, a new method of Baijiu spectral signal acquisition was realized by combining LIBS with Baijiu detection. Aiming at addressing the shortcomings of high breakdown thresholds and poor signal stability due to the direct breakdown of Baijiu with high ethanol content, a high-frequency atomization system based on ultrasonic technology is proposed to realize the efficient extraction of Baijiu plasma spectral signals. With regard to the selection of the number of nodes, weights and thresholds of the implicit layer of the back-propagation (BP) network, an optimization model based on the combination of the particle swarm optimization (PSO) algorithm combined with the genetic algorithm (GA) is proposed to realize the construction of the BP optimal network architecture. By constructing a secondary optimization seeking network model based on OptGSCV, the technical problem of mismatch between optimal parameter selection and optimal network construction is solved, and a new network integrating an intelligent qualitative analysis algorithm and a traditional classification algorithm is realized. The experimental results show that the proposed OptGSCV quadratic optimization network combined with the AS-LIBS multidimensional Baijiu high-precision classification model not only introduces an innovative and high-efficiency detection method for the Baijiu industry, but also provides important technical support and new ideas for the key areas of food safety production and Baijiu quality control. [ABSTRACT FROM AUTHOR]

A calix[3]carbazole-based cavitand was conveniently synthesized. It was found that the cavitand with adjustable conformation could show excellent complexation with fullerenes C60 and C70 in both solution and the solid state. Moreover, the crystal structures of the host–guest complexes show that the cavitand can stack into channel-like architectures, in which fullerenes are orderly arranged inside. [ABSTRACT FROM AUTHOR]

A novel class of cyclometalated macrocycles [(Cp*Ir)2(R–NC–C6H2–CN–R)2]2(pyrazine)2·(OTf)4[R = Ph (4a), p-MeOC6H4(4b), p-MeC6H4(4c), p-ClC6H4(4d), Me (4e)]; [(Cp*Rh)2(R–NC–C6H2–CN–R)2]2(pyrazine)2·(OTf)4[R = Ph (4a′), p-MeOC6H4(4b′), p-MeC6H4(4c′)] and [(Cp*Ir)2(R–CN–C6H4–NC–R)2]2(pyrazine)2·(OTf)4[R = Ph (5a), p-MeOC6H4(5b)] was stepwise constructed through the double-site C–H activation of aromatic bis-imine substrates. The structures of binuclear complexes and tetranuclear macrocycles were confirmed by single-crystal X-ray diffraction. Isomers were found both in binuclear species and macrocyclic complexes. Flexible substrates led to the existence of isomers for binuclear species, yet gave no isomers after macrocyclic constructions; rigid ones, in contrast, led to isomers only for macrocyclic species. The isomers of tetranuclear macrocycles were thermodynamically stable to reversible transformation on a scale of days. Robust bonding and a certain degree of rigidity were invoked to explain the existence of isomers. This is the first example, to our knowledge, in which coordinated macrocycles containing half-sandwich Cp*M (M = Ir, Rh) fragments have been constructed, without a dynamic reversible process. [ABSTRACT FROM AUTHOR]

Reactions of half-sandwich iridium and rhodium complexes [Cp*MCl2]2(1a: M = Ir, 1b: M = Rh) and the half-sandwich ruthenium complex [(p-cymene)RuCl2]2(1c) with 4DPDS gave the corresponding binuclear complexes [{Cp*MCl2]2}(μ-4DPDS) (2a: M = Ir, 2b: M = Rh) and [{(p-cymene)RuCl2]2}(μ-4DPDS) (2c), which can be converted into binuclear metallamacrocycles. The metallamacrocycles [Cp*M(μ-4DPDS)Cl]22+(3a: M = Ir, 3b: M = Rh) and [(p-cymene)Ru(μ-4DPDS)Cl]22+(3c) are composed of two half-sandwich units and two 4DPDS ligands with the same chirality. The macrocycle 3cis chiral and changes its shape slightly depending on the guests accommodated above and below the cavities. [ABSTRACT FROM AUTHOR]

Self-sorting behavior of a four-component host–guest system was found, which could be utilized to construct a linear supramolecular alternating copolymer. [ABSTRACT FROM AUTHOR]

Versatile and efficient procedures for the construction and modification of organometallic macrocycles with half-sandwich Ir corners viaC–H activation and self-assembly have been developed. [ABSTRACT FROM AUTHOR]

TEMPO promoted cycloaddition reaction of different kinds of ketohydrazones or aldohydrazones with 3-phenacylideneoxindoles showed very interesting molecular diversity according to the chemical structures and reaction conditions. The reactions with 1-(3,4-dihydronaphthalen-1-ylidene)-2-arylhydrazines or 1-cyclohexylidene-2-arylhydrazines in acetonitrile at 80 °C afforded functionalized spiro[benzo[h]cinnoline-3,3′-indolines] or spiro[cinnoline-3,3′-indolines] via aza-Diels–Alder reaction of the in situ generated 1,2-diaza-1,3-diene. The reactions with 2-(2-phenylethylidene)-1-arylhydrazines in dioxane afforded functionalized spiro[indoline-3,3′-pyrazoles] though a [3+2] cycloaddition reaction of the in situ generated 1,3-dipolar azomethine imine. On the other hand, a similar reaction in acetonitrile unusually resulted in pyrazole derivatives via sequential [3+2] cycloaddition and a ring-opening process. [ABSTRACT FROM AUTHOR]

Despite dramatic advances in the template-directed synthesis of archetypal [2]rotaxanes, higher order rotaxanes with multiple molecular components (rings or dumbbells) are relatively daunting subjects owing to their synthetic challenges. With unique interlocked architectures, higher order rotaxanes have found applications in artificial molecular machines. In this feature article, we will focus on the recent advances in higher order rotaxanes with well-defined structures. Different types of rotaxane architectures will be described, and their synthetic approaches will be highlighted. Moreover, the stimuli-responsive molecular motion with increasing complexity in these diverse architectures will also be discussed. [ABSTRACT FROM AUTHOR]

The first example of a thio-functionalized zincophosphite material (NTOU-2S) incorporating the 2,5-thiophenedicarboxylate (TPDC) ligands was synthesized using a hydro(solvo)thermal method and structurally characterized by single-crystal X-ray diffraction. Interestingly, the perspective view of the crystal structure for NTOU-2S is similar to our previous report of NTOU-2 but the carboxylate organic ligands (TPDC for NTOU-2S; 1,4-benzenedicarboxylate, BDC, for NTOU-2) in both compounds adopt different types of bis-monodentate coordination models (the unusual cis bonding versus a trans linkage) to bridge the metal atoms of inorganic tubes in the formation of large-channel zincophosphite frameworks, resulting in structural and functional diversities. The thiophene-based compound also displayed higher thermal stability and removal ability for the softer Hg2+ cations from water solutions than the performance of sulfur-free NTOU-2. In addition, the synthesis, structural characteristics, removal properties of heavy metal cations, and thermal and chemical stabilities for both compounds were also reported. [ABSTRACT FROM AUTHOR]

Water-soluble [3]pseudorotaxane with enhanced fluorescence emission was successfully constructed and applied in cell imaging and photodynamic cancer therapy. [ABSTRACT FROM AUTHOR]

p-TsOH promoted annulation reaction of 3-(indol-3-yl)maleimides and (indol-2-yl)diphenylmethanols in chloroform afforded functionalized pyrrolo[3′,4′:6,7]cyclohepta[1,2-b:4,5-b′]diindoles in satisfactory yields, in which a formal [4+3] cycloaddition and an unprecedented rearrangement of the maleimide motif from the C3- to C2-position of the indole ring was firstly observed. Alternatively, the similar reaction of 3-(indol-3-yl)maleimides and 3-hydroxy-3-(indol-3-yl)-indolin-2-ones in acetonitrile gave functionalized spiro[indoline-3,9′-pyrrolo[3′,4′:4,5]cyclopenta[1,2-b]indole] in good yields and with high diastereoselectivity. On the other hand, p-TsOH promoted reaction of 3-(indol-3-yl)maleimides and 2-hydroxy-2-(indol-3-yl)-indene-1,3-diones gave functionalized spiro[indene-2,9′-pyrrolo[3′,4′:4,5]cyclopenta[1,2-b]indoles] as major products and spiro[indene-2,9′-pyrrolo[3′,4′:6,7]cyclohepta[1,2-b:4,5-b′]diindoles] as minor products. [ABSTRACT FROM AUTHOR]

Bisphenol A, a toxic chemical, is widely used in the preparation of epoxy resins. Therefore, the use of harmless biomass-based raw materials to replace bisphenol A in the preparation of epoxy resin has attracted extensive attention. A demethylated-lignin-based epoxy resin adhesive was prepared. After lignin was modified in a LiBr/HBr system, the phenolic hydroxyl group content of the obtained demethylation lignin (DL) increased to 6.19 mmol g−1, and the tensile strength of the as-prepared DL-modified adhesive (–OH content of the DL = 6.19 mmol g−1) increased to 62.50 MPa, which was much higher than the adhesive modified by raw lignin (38.89 MPa). Due to its excellent crosslinking density, the DL-modified adhesive retained more than 85% of its tensile shear strength performance after being soaked in water for 48 h or frozen at −25 °C for 48 h. Therefore, this adhesive has a wide range of application prospects in furniture and plywood manufacturing. [ABSTRACT FROM AUTHOR]

Triarylborane-based discrete metal-carbene supramolecular cages [M3(1)2](PF6)3 (M = Ag, Au) were synthesized and characterized. The new hexacarbene assemblies show a significant solvatochromic effect in solvents of different polarity. Furthermore, the reversible fluoride binding property of [Au3(1)2](PF6)3 was investigated by UV-vis absorption and fluorescence titrations. This work holds promise for future developments in the area of highly emissive and stimulus-responsive NHC-metal assemblies. [ABSTRACT FROM AUTHOR]

A water-soluble 2,6-helic[6]arene derivative was conveniently synthesized, and it showed strong binding abilities towards quaternary phosphonium salts in aqueous solution. Moreover, an acid/base controlled switchable complexation process was also described. [ABSTRACT FROM AUTHOR]

A novel luminescent macrocycle has been conveniently synthesized, which displays flexible conformations and interesting solid-state host – guest properties. Besides, the macrocycle exhibits excellent thermally activated delayed fluorescence (TADF) emission with a photoluminescence quantum yield of 80%, which represents the highest value among reported TADF macrocycles. [ABSTRACT FROM AUTHOR]

A new divergent intermolecular cascade annulation reaction of N-(arylsulfonyl)acrylamides with dual alkyl C(sp3)–H bonds for producing two types of five-membered rings, indanes and pyrrolidin-2-ones, is described. By using cycloalkanes and common alkanes as a one-carbon unit, an intermolecular [4+1] cascade carboannulation of N-(arylsulfonyl)acrylamides was achieved via a sequence of three C–H bond functionalization/aryl migration/desulfonylation that enables the formation of three C–C bonds and one N–H bond. When the one-carbon unit was changed to cycloalkyl ethers, the alternative intermolecular [4+1] cascade heteroannulation reaction occurred and allowed the construction of two C–C bonds and one C–N bond through dual C–H bond functionalization, aryl migration and desulfonylation cascades. [ABSTRACT FROM AUTHOR]

An iridium(iii)-catalyzed C–N-bond-forming direct synthesis of carborane azo derivatives was developed. The reaction of o-carborane monocarboxylate with aryldiazonium salt in the presence of a catalytic amount of [Cp*IrCl2]2 and NaOAc in CH3CN at 80 °C gave the corresponding carborane azo derivative in good yield. A series of cyclometalated iridium/rhodium complexes that contain Cp*M–B (M = Ir, Rh) bonds, and are stabilised by the intramolecular coordination of nitrogen donors, were successfully isolated and structurally characterised. [ABSTRACT FROM AUTHOR]

Two pillar[5]arene-based [1]rotaxanes with salicylaldimine as the stopper were synthesized and characterized fully, and could be further applied in the fluorescence turn-on sensing of Zn2+ in water. [ABSTRACT FROM AUTHOR]

Reported herein is a racemate of a chiral nanocluster [Cu28H20(S2P(OiPr)2)9]−, which has a tetrahedral Cu4 core embedded in a peculiar Cu24 shell. The Cu28H20 framework conforms to idealized C3 symmetry. The positions of the hydrides were determined by a combinatorial use of 2H NMR and SC-XRD, revealing four different coordination modes: face-capping μ3-H, butterfly μ4′-H, tetrahedral μ4-H, and square-pyramidal μ5-H. These coordination modes were authenticated by DFT calculations. Simple empirical rules were developed for assigning the H NMR spectra. One exposed Cu atom from the Cu4 core and 13 exposed surface hydrides are easily accessible and thus may have catalytic functions. [ABSTRACT FROM AUTHOR]

Photochemical reactions are vital synthetic means for the synthesis of natural products and highly strained molecules. However, it remains an immense challenge to control the chemo- and regioselectivity in the photoreactions of anthracene derivatives while maintaining high reactivity. Herein, we report the synthesis of two photoactive metallarectangles 1a and 1b by coordination-driven self-assembly of 2,6- and 2,7-bifunctionalized anthracenes with a half-sandwich rhodium template. By taking advantage of the rhodium template, the anthracene groups within the metallarectangles can be preorganized in a parallel fashion and exclusively undergo a photochemical [4 + 4] cycloaddition. As a result, the syn-photodimers were obtained in quantitative yields under irradiation at 365 nm. The photocycloaddition of metallarectangles 1a and 1b was found to be reversible via photo- and thermal cleavage reactions, even after repeating three times. Furthermore, pure organic photodimers 3a and 3b, which are difficult to synthesize by conventional organic methods, can be readily dissociated from the metalloassemblies in high yields. [ABSTRACT FROM AUTHOR]

Direct metathesis reaction between Mg2Ge and SnCl4 is introduced to prepare porous hierarchical Ge–Sn binary composites, in which the Ge and Sn components are distributed uniformly, with a tap density of 2.3 g cm−3. As an anode for LIBs, the Ge–Sn composite displays a specific capacity of 980 mA h g−1 at 0.5 A g−1 after 250 cycles, and 890 mA h g−1 at 3 A g−1 over 1700 cycles. When paired with a commercial LiCoO2 cathode, a 3.6 V full battery with a capacity of 830 mA h g−1 is obtained. [ABSTRACT FROM AUTHOR]

We present the finding of a dimeric ACE2 peptide mimetic designed through side chain cross-linking and covalent dimerization. It has a binding affinity of 16 nM for the SARS-CoV-2 spike RBD, and effectively inhibits the SARS-CoV-2 pseudovirus in Huh7-hACE2 cells with an IC50 of 190 nM and neutralizes the authentic SARS-CoV-2 in Caco2 cells with an IC50 of 2.4 μM. Our study should provide a new insight for the optimization of peptide-based anti-SARS-CoV-2 inhibitors. [ABSTRACT FROM AUTHOR]

A series of complexes of novel chelating thione-alkene S(η2-C=C)S tridentate ligands bound to late transition metals (Ir, Rh, Pd) were isolated and characterised. Counter-anions play an important role in the binding of the alkene moiety to the metals. Different solvents were observed to affect the stability of the rhodium complexes. [ABSTRACT FROM AUTHOR]

A facile synthetic method to form cage-annulated crown ether with anchored imidazolium units was developed. The present work verified the potential application of the metal–carbene template approach (MCTA) in the preparation of novel flexible polyimidazolium cages by photochemical [2+2] cycloaddition reactions and may provide a new method for the preparation of flexible pure organic cages with incorporation of a variety of functional sites. [ABSTRACT FROM AUTHOR]

We herein described a visible light induced nickel(II)-catalyzed cross-coupling of secondary phosphine oxides with aryl halides. The Ni(I) species and chlorine atom radical Cl˙ were generated via the ligand to metal charge transfer (LMCT) process of the NiCl2(PPh3)2, which allows nickel(IV)-phosphorus species in situ formation, giving various tertiary phosphine oxides under photocatalyst-free conditions. [ABSTRACT FROM AUTHOR]

The development and application of nano-drug carrier systems have opened up unprecedented opportunities for tumor treatment. However, eliminating the related liver toxicity is still very challenging because hepatotoxicity is the most severe adverse effect of chemotherapy and nanotherapy. Herein, a highly atom-economical bioactive nanocarrier delivery system is shown. This carrier is assembled from oleanolic acid (OA), which is abundantly present in Chinese medicinal plants and has shown potent antioxidant, antitumor, and hepatoprotective properties. Molecular simulation and experimental characterization have demonstrated that the assembly process of OA-encapsulated paclitaxel (PTX) to form OA–PTX nanoparticles is mainly through hydrophobic interactions and hydrogen bonding interactions. In vitro and in vivo experiments confirmed that OA and PTX have synergistic antitumor effects due to their different antitumor mechanisms. As expected, liver injury induced by PTX was significantly reduced due to the hepatoprotective activity of OA. The prepared nanomedicine has high drug loading capacity and excellent targeting, as well as good biocompatibility and low in vivo toxicity, which ensure the effectiveness of the tumor treatment and the safety of the body. The present study provides new ideas for the development of nanocarriers and avenues for active natural products in reducing drug side effects. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate the design and fabrication of a series of cylinder-like, hexazido-terminated MI–CNHC (M = Ag, Au) complexes. Moreover, we present for the first time a process-tracing and aggregation-induced emission (AIE) study of a covalent postassembly modification (PAM) process of the AuI–CNHC cylinders, highlighting the excellent versatility and complexity of functionalised poly-NHC compounds as a new type of molecular platform for novel applications. [ABSTRACT FROM AUTHOR]

A highly regioselective Cu-catalyzed difunctionalization of different N-heteroarene salts such as quinolinium and benzothiazolim salts was developed with ether and X− (X = Br, Cl) as the halogen source under mild conditions. This transformation involved the combination of oxidative coupling, selective free radical resonance and a copper-catalyzed halogen atom-transfer radical process. The regiochemistry was further verified by DFT calculations. This method not only provided an efficient way to prepare various substituted azaarenes but also achieved the selective construction of C(sp2)–X (X = Br, Cl) bonds from a halogen anion and nucleophilic carbon atom via a free-radical process. [ABSTRACT FROM AUTHOR]