Metal-organic frameworks (MOFs) are a new class of crystalline porous materials, having wide pores which provide extremely high specific surface areas, larger than those typically observed in more common porous materials like zeolites or activated carbons. This peculiar property combined with the frequent presence of open-metal sites, makes them very promising for a broad range of applications, spacing from gas storage or separation, drug delivery, toxic air removal, chemical detectors, etc. However, the industrialization of MOFs is still facing difficulties because of their low stability to water or even air moisture, a substance difficult to avoid in applications like those mentioned. Another issue concerning MOF industrialization consists in the low bulk density of the micrometric powder grains, which typically constitute such materials. Unfortunately, their low mechanical stability seems to make difficult even to enhance the packaging by simple mechanical compaction. In this review, we will particularly focus on the current state of art involving the MOF HKUST-1, especially on the degradation process involved when this MOF interacts with water molecules. Furthermore, we will show the connection between water and mechanical stability, bringing to attention of a study where solid tablets of HKUST-1 powder have been realized without any loss of crystallinity or porosity because of an accurate study on the effects of different degree of hydration during the tableting phases. In addition, in order to highlight the causes of damages induced in the framework upon interaction with water, a comparison with other two copper carboxylate MOFs will be shown, namely STAM-1 and STAM-17-OEt, which differ from HKUST-1 uniquely for the organic ligands.

Advances in the synthesis of low bandgap (E _g < 1.5 eV) conjugated polymers has produced organic materials capable of absorbing near-infrared (NIR) light (800—2500 nm), with these materials first applied to photodiode NIR detectors in 2007 as an alternative to more traditional inorganic devices. Although the development of organic NIR photodetectors has continued to advance, their ability to effectively detect wavelengths in the low-energy portion of the NIR spectrum is still limited. Efforts to date concerning the production of photo-diode-based devices capable of detecting light beyond 1000 nm are reviewed.

Aqueous pollution from industrial dyes and antibiotics has brought up much threat to our daily healthy life. In the present work, hydrogenated black TiO ₂ nanoparticles (H-TiO ₂) are synthetized, their properties are studied, and their potentials in removing dyes (methylene blue, M.B.) and antibiotics such as tetracycline hydrochloride (TC) and ciprofloxacin (CIP) are explored with the support of statistical optimization. The operational controlled parameters such as catalyst amount (g L ⁻¹), pH and irradiation time (min) were optimized using Design of Experiment (DOE) L9 Taguchi Orthogonal Array. From Analysis of Variance (ANOVA) results, it can be seen that irradiation time is the most influencing parameter for % MB color removal, % Degradation of TC and CIP, over catalyst amount and pH. The optimal parameters found here are 0.50 g L ⁻¹ of hydrogenated H-TiO ₂-750 as catalyst, pH 4 for MB, pH 11 for TC and pH 2 for CIP, respectively. In addition, an irradiation time of 30 min shows a maximum MB color removal of 95.05%, TC 94.8% and CIP 92.25%. Irradiation time is found to be the most influencing parameter (71.08% for MB, 55.33% for TC and 52.77% for CIP) followed by catalyst amount (28.82% for MB, 44.19% for TC and 41.5% for CIP) and in the end pH (0.09% for MB, 0.47% for TC and 5.72% for CIP). With the use of hydrogenated H-TiO ₂-750, the dye and antibiotics degradation reaches almost 40% more than using TiO ₂ pristine anatase.

President Kennedy’s dream of obtaining fresh water from seawater seemed has been realized as a great scientific achievement. As Norihito Tambo predicted, seawater reverse osmosis desalination (SWRO) has become a major technology in Middle Eastern countries. SWRO requires less energy compared with the distillation method. Even Middle Eastern countries, where the distillation method is still a major technology, have started to adopt the RO method in new desalination plants in accordance with government policy and following the trend of developing larger (half mega-ton per day and larger) so-called Mega-SWRO plants. With these trends in the global market, the requirements of sustainable SWRO desalination as green desalination for the 21 ^st century are as follows: (1) conservation of energy resources: renewable energy, (2) innovation of desalination technologies: new advanced membrane and membrane systems, (3) reduction of marine pollution: green desalination. The government-supported Mega-ton water system project has been conducted to solve issues related to (2) and (3). The combination of a low pressure SWRO membrane and a low-pressure, two-stage, and high-recovery SWRO system, also referred to as a SWRO-PRO hybrid system, it has enabled 20% energy reduction and 30% energy saving in total. Likewise, low environmental impact as green desalination has established a reliable operation using less chemical and chemical cleaning. In terms of low-cost renewable energy, in particular, solar energy is now available to solve issues related to renewable energy. By combining these sophisticated technologies, desalinated water has become affordable at $ 0.50/m ³ or less (as low as $ 0.28/m ³). SWCC has announced their future plans for SWRO. The main topic is directed to brine mining to obtain precious materials from the brine of SWRO. This plan will be connected to water and green hydrogen for a sustainable future.

Nanomaterials are attracting renewed interest due to their novel properties, which are not seen in their conventional micro state counterparts. They are used in advanced applications in the fields of catalysis, medicine, electronics, optics and membranes. Electrospinning is one of the simplest and cheapest methods to make nano-porous polymer membranes, and these offer a large surface area-to-volume ratio, high porosity and small pore size. These electrospun nonwoven mats could be employed in myriad applications ranging from filtration, sensors, electrode materials, drug delivery, cosmetics, and tissue scaffolding. This technique can introduce novel functional characteristics, and hence by changing the basic experimental set up, solvent, solution and polymer characteristics can alter the composition, morphology, and porosity of the processed material. The unique structural and functional characteristics inherited at submicron to nanoscale dimensions via electrospinning makes it an attractive technique for advanced industrial applications.

Fullerenes have attracted much attention because of their unique electronic structure and spherical cage shape. Specially, fullerenes have been widely used as guest in supramolecular chemistry due to their spherical structures. Recently, the supramolecular complexes of fullerenes and several types of carbon nanorings have been constructed and investigated. The complex of fullerene in carbon nanoring is like a Saturn, and this unique kind of supramolecular complexes will have potential applications in chemical, material and physical fields. In this review, various complexes of fullerene in carbon nanoring and their special properties are described. We hope to expand the application of these supramolecular complexes in various fields.

Oxidation is a key transformation in chemistry being involved in a wide range of processes. In natural products, this reaction plays a critical role in the biosynthesis of several classes from different sources. In this context, the oxidation of menthol to menthone is an important reaction with a variety of applications in several fields, such as natural products, organic synthesis, and medicinal chemistry. Considering this, the present article aims to review different methodologies and oxidation reagents capable of performing this transformation, including the green chemistry process.

The dissociative chemisorption and energetically driven migration of atomic hydrogen on heterogenous electrocatalysts, i.e., hydrogen spillovers, which occur during electrochemical turnovers, have been intensively investigated recently on high-performance electrocatalysts for hydrogen evolution reaction. The elucidation of the hydrogen spillover not only reshapes the mechanistic understanding of the catalytic landscape but also aids in formulating efficient reaction pathways for catalyst designs. This perspective hence concisely summarizes the status of research on the hydrogen spillover effect in recent years, as well as the experimental methods to characterize the hydrogen spillover process and presents a prospect for future research direction.

Carbon dots are small carbon nanoparticles with effective surface passivation by mostly organic species. For such a simple and well-defined nanoscale structure, the classical and most reliable synthesis is the use of pre-existing small carbon nanoparticles for surface chemical functionalization with organic molecules. However, a more popular synthetic approach in the literature has been the “one-pot” carbonization of organic precursors, which with appropriate processing conditions could in principle create local structures in the resulting dot-like entities that may be comparable to the structural configuration in carbon dots, though the carbonization can also easily produce colored organic materials crosslinked into the sample structures. An extreme example was the thermal processing of the specific organic precursor mixtures including only citric acid with formamide or urea to yield samples of red/near-IR absorption and emission features, which prompted the claims of “red/near-IR carbon dots”. In reality, these spectral features have nothing to do with nanoscale carbon, let alone carbon dots, but simply associated with molecular dyes/chromophores produced in chemical reactions of the specific precursor mixtures under the thermal processing conditions intended for carbonization. In this work, the isolation and identification of the responsible molecular dyes/chromophores were pursued. The results present further evidence for the conclusion that the red/near-IR absorption and emission features have nothing to do with carbon dots.

The properties of surfaces are crucial for many processes in a variety of areas in biology, industry, and daily life. Surprisingly, even though surface phenomena have been studied for more than 200 years by some of the greatest physicists, mathematicians, and engineers, there are still quite a few enigmas to be solved. This paper presents some fundamental enigmas related to the surface tensions of liquids and solids that were either partially solved or yet mostly unsolved.

Dried foam films (DFF) of graphene oxide (GO) has been prepared by dipping a titanium mesh in the solution of GO, and then it was reduced by electrochemical method. Next, the as-prepared water-containing reduced grapheme oxide (rGO) DFF film works as electrode for electrocpolymerization of aniline onto its surface for preparing a polyaniline/graphene monolith while the titanium mesh acts as the electron collector. The as-obtained composite film is binder-free and has highly surface area, conductivity, and can be used for supercapacitor electrode. Then network of plenty polyaniline nanoparticles formed on the surface of rGO film by electrochemical polymerization, which works as the material for pseudocapacitance. When the film is used as a supercapacitor electrode, the maximum specific capacitance is as high as 633.4 F g ⁻¹ and the specific capacitance retains 75% of the initial after constant charge discharge 5000 cycles at current density of 10 A g ⁻¹, indicating that the nanocomposite is a suitable active material for supercapacitors.

The Meyer-Schuster rearrangement reaction has been known for almost a hundred years. It has been used to prepare unsaturated aldehydes, ketones, and even esters from propargyl alcohols. Thirty years ago, the same reaction was found to produce also α-halogenated aldehydes and ketones under suitable conditions. In the last thirty years, several methods have been developed utilizing the Meyer-Schuster rearrangement in the synthesis of halogenated building blocks for use in synthetic chemistry. In this perspective, we describe the progress in the field.

Two novel fluorenyl-porphyrins 2Flu-TPP and 4Flu-TPP serving as charge trapping elements are designed and synthesized through BF ₃.Et ₂O catalyzed Friedel-Crafts reaction. With steric hindrance building blocks of fluorene units, 2Flu-TPP and 4Flu-TPP present highly nonplanar 3-dimensional structure, which could effectively inhibit molecular packing and intermolecular arrangement of porphyrins. As charge trapping elements, porphyrin groups provide the hole trapping sites, while fluorene units act as a hole blocking group to reduce the formation of leakage current paths. The pentacene-based organic field effect transistor memory devices based on 2Flu-TPP and 4Flu-TPP show memory windows of 48.93 and 49.20 V, respectively. The 2Flu-TPP device shows reliable endurance property with a large ON/OFF current ratio (1.1×10 ⁷) and good charge retention time (2.41×10 ⁵ after 2×10 ³ s). This study suggests that porphyrin based steric hindrance small molecular elements have great promise for high-performance organic field effect transistor memory.

Chemical crosslinking technology was rapidly developed and utilized to prepare structurally fixed, stabilized and functionalized polymer nanoassemblies and nanoarchitectures by covalently reinforcing the interactions between the polymer chains. This perspective reviewed recent advances on the crosslinked polymer nanoassemblies and their applications, mainly in drug delivery. Moreover, possible future research outlooks in the field of Shell-crosslinked polymer nanoassemblies were also stated and discussed.

As one of the key  components of perovskite solar cells (PSCs), hole transport materials (HTMs)  effectively improve the performance and stability of the devices and greatly promote the development of PSCs. At present, due to the advantages of flexible structure design, simple synthesis, low-cost and abundant raw materials, organic  small molecule HTMs have been studied extensively by researchers. Among them, small molecule HTMs  with donor–acceptor (D –A) type structures for PSCs have received great attention in the last few years because of their high hole mobility due to strong dipolar intermolecular interactions,  minimizing ohmic losses of the contact, good stability, and high solubility. In this review, we mainly introduce some representative  D−A−D-type  small molecule HTMs, summarize and comment on their properties, and discuss the relationship between molecular structure and performance parameters of devices. Finally, based on the current research, the future design of new efficient HTMs is prospected.

In this paper, we developed and validated a simple and accurate thin layer chromatography method for the analysis of the chemical components in the plants of genus Lindera (the Lauraceae family). High performance liquid chromatography method was used to verify the results of thin layer chromatography analysis.

Using renewable natural polymer resources to develop functional therapeutics and nanomedicine is a sustainable research area at the interface of multidisciplinary subjects such as green chemistry, polymer science and technology, nanobiomaterial and clinical medicine. It is disclosed that natural polysaccharides and their derivatives exhibited good biocompatibility, promising drug/gene delivery efficiency and immunomodulation capability, which have attracted tremendous attention in recent decades. This article reviewed up to date progresses of various natural polysaccharides and their derivatives as immunomodulators. The impact of molecular factors on immunomodulation-related features were stated, moreover, possible future outlooks on the natural polysaccharide-based immunomodulators were also discussed.

Spiro[fluorene-9,9′-xanthene] has received great attention due to its unique structure and possesses wide applications in the field of material chemistry. Herein, we highlighted low-cost, stable and high-performance spiro[fluorene-9,9′-xanthene] derivatives for organic electronics.

Carbon quantum dots (C-dots) are emerging semiconductor nanomaterials consisting of earth-abundant C, O, and N elements. C-dots have many advantages such as high quantum yield, good photo- and chemical-stability, low-cost, low-toxicity and easy synthesis with earth-abundant precursors. In this minireview, we summarized and updated the most recent research works for the synthesis of the fluorescent and phosphorescent C-dots. In the end, we also give our owner views for the challenges and research directions for C-dots.

Conventionally, N-bromosuccinimide (NBS) is a brominating and oxidizing reagent in organic synthesis. In our research on N-haloimides in organic transformation, we proposed the concept of utilizing N-haloimides like NBS as an amination reagent, i.e., direct incorporation of imido unit to the target molecules to achieve amination, with the assistance of positive halogen(I). In this paper, we would like to summarize the amination of various fundamental substrates with N-haloimides as the amination reagents. We have developed an N-haloimide-DBU (Lewis base activator) combination system, which affords halogen bonding complex and subsequent ion pair intermediate via halogen transfer. All these reactions feature convenient and readily available reagents, mild conditions, simple execution, broad halogen scope, high efficiency and metal-free. The utilization of N-haloimides as versatile aminating reagents has been demonstrated and further application of the synthetic protocol for the preparation of bioactive and optical materials is expected.

Usually filled with a whey cheese-based sweet cream a few minutes before serving in order to prevent the moisture of the cream from softening the waffle and thus preserve its crispness, Sicilian cannoli are an ancient pastry of Sicily widely appreciated across the world. Another method to protect the “scorza” from quick softening is to coat the inner surface of the waffle with melt chocolate, altering the original taste of the pastry. We now report a simple method to stabilize Sicilian cannoli against moisture migration based on coating the inner layer of the waffle with a thin layer of pure glycerol.

Purely organic room-temperature phosphorescence (RTP) materials are promising candidates for high-tech applications. Herein, we highlight new development that promotes RTP emission of organic small molecules, high phosphorescent efficiency and long lifetime, via inter/intro-molecular halogen bonding.

Lindera glauca  (Sieb. et Zucc.) Bl is Chinese herbal medicine known as Niujin tree or Leigongzi. Alkaloids, flavonoids, terpenes, volatile oils,  etc ., are found in  L. glauca,  exhibiting some pharmacological activities such as anti-bacterial, anti-influenza virus, anti-fungal, antioxidant activities, an effect on bronchial and intestinal smooth muscle, and so on. Herein, we summarized chemical compositions and physiological activities  of  L. glauca  for future research.

This work describes the synthesis of piperazine hydrochloride in multigram scale and high yields with promising industrial applications. This methodology is simple, fast, safe, low cost, and applicable to the synthesis of a wide variety of piperazine derivatives, being very useful in medicinal chemistry and other fields.

The next-generation energy storage focuses on sustainability and renewability, facilitating the process of metal-air batteries and fuel cells. Nevertheless, their performances are suffering from the tardy development of the elaborate design and large-scale synthesis strategy of cost-efficient electrocatalysts. In this work, a convenient strategy for facile synthesizing electroactive material is proposed. As a result, a trifunctional Co/C catalyst is fabricated via a convenient calcination process, utilizing the pyrolysis of cobalt acetate and melamine. The prepared Co/C sample delivers a positive half-wave potential of 0.75 V in oxygen reduction reaction (ORR). Furthermore, the low overpotentials at 10 mA cm ⁻² are shown in alkaline conditions for oxygen evolution reaction (OER, 388 mV) and hydrogen evolution reaction (HER, 202 mV). The improved activity is mainly due to the interaction between Co and the in situ formed carbon carrier. The promising trifunctional activities endow the Co/C sample with a bright prospect in metal-air batteries and overall water splitting.

Extensive auxiliary density functional theory (ADFT) computations were performed to study the most stable structures, stabilities and chemical reactivity toward O ₂ of bimetallic Ni _mCu _n ( m + n ≤ 6) clusters. The shape of the most stable structures changes as the number of Ni and Cu atoms of the system under study increases with a consequent change of the energy, magnetic and reactivity properties. All obtained minimum-energy structures for these bimetallic systems composed with three and four atoms possess triangular and rhombic structures, respectively. According to our computations, the most stable structures for Ni ₄Cu, Ni ₃Cu ₂, and Ni ₂Cu ₃ clusters are trigonal-bipyramidal, while, for the NiCu ₄ cluster, two structures were identified as the most stable (with planar and trigonal-bipyramidal structures, respectively). The most stable structure for the Ni ₅Cu cluster is octahedral, while for the Ni ₄Cu ₂, Ni ₃Cu ₃, Ni ₂Cu ₄, and NiCu ₅ clusters, an incomplete pentagonal bipyramid was found as the ground-state structure. For all cluster sizes, as the number of Cu atoms in the system increases, the magnetic moment per atom tended to decrease. The O ₂ adsorption on bimetallic Ni _mCu _n ( m + n = 6) clusters is more favored when O ₂ binds by a bridge-type bond. Moreover, our computations indicate that O ₂ is preferentially adsorbed on the Ni atoms of bimetallic Ni _mCu _n ( m + n = 6) clusters.

Phthalide is a common type of functional group in natural products and synthetic motifs, which has a structural feature containing a benzo five-membered lactone ring. Phthalide is also a popular pharmacophore in many bioactive natural products and clinical drugs. This review focuses on chemical synthesis methods of phthalides established in the past ten years.

The bandgap ( E_g) of conjugated materials effects a variety of critical properties such that efforts to control the bandgap have become a basic tenet in the design of conjugated polymers. One goal of such efforts is to minimize the E_g with the goal of producing technologically useful low bandgap ( E_g < 1.5 eV) polymers. This perspective will introduce the two primary approaches to low E_g polymers ( i.e., quinoidal systems and donor-acceptor frameworks) and discuss important new directions for both design principles.

The results of the first tests aimed to assess antifouling activity of new AquaSun sol-gel paint coated on shipbuilding steel immersed in highly polluted port seawaters, compared to a state-of-the-art self-polishing commercial silyl acrylate antifouling topcoat containing high amounts of cuprous oxide and copper pyrithione, are promising.

Amphiphilic 4-(methylthio) benzoic acid (HMBA) combining soft methylthio and hard carboxylic groups was used to construct two isostructural coordination polymers of [Cu(MBA)] _n ( CP- 1) and [Ag(MBA)] _n ( CP-2), and one complex of Cu ₂(MBA) ₄(CH ₃CN) ₂·CH ₃CN ( 3). This ditopic HMBA ligand realizes stable coordination of its carboxylic group with low-valent soft Cu ⁺ ion ( in-situ reduction from Cu ²⁺) under the assistance of methylthio groups, forming CPs of CP- 1 and CP- 2. Meanwhile, based on the theory of hard and soft acid and base (HSAB), harder Cu ²⁺ ions ( in-situ oxidation from Cu ⁺) only coordinate to carboxylic groups, affording a paddle-wheel dinuclear complex 3. These two CPs were also taken for luminescent researches in solid state. CP-1 exhibits single-peak emission at 540 nm while CP-2 emits both at 499 and 528 nm with green luminescence. The emissions of CP-1 and CP-2 are both attributed to ³MLCT (triplet metal-to-ligand charge transfer) excitation state.

More attentions have been paid for developing anti-counterfeiting technologies to fight the endless emergence of fake and inferior products. Compared with inorganic quantum dots, colloidal carbon dots (C-dots) are emerging fluorescent nanomaterials, which have been used for various types of optical and electrical applications, because they have composition-dependent optical properties, including high quantum yield, tunable absorption/emission spectra and good chemical-/photo-stability. In this minireview, we summarized and updated the most recent research works for the use of colloidal C-dots for optical anticounterfeiting applications. We focus on the fluorescent, persistent luminescence and phosphorescent C-dots. In the end, we enclosed this minireview with our owner perspectives on the challenges of C-dots based anticounterfeiting.

Regioselective synthesis of carbohydrate building blocks by the application of biocatalytic approaches represents a convenient and sustainable way for the production of pharmaceuticals. The enormous potential of enzymes for the transformation of synthetic chemicals with high regioselectivity is on increasing awareness. This perspective focuses on showing some of the advances on the use of lipases engineering as immobilized catalyst for regioselective deprotection processes for potential industrial production glycoderivatives building blocks.

Phosgene, an important chemical warfare agent (CWA), has received great attention in the field of counterterrorism and public safety monitoring. Developing new sensing methods/tools for efficient detection of phosgene is an urgent challenge to be solved. For chemists, it is pivotal to create fast, low cost, portable, selective, sensitive, as well as visualizable chemical sensors/probes for real-time phosgene detection. This article reviewed and discussed current trend and statement of phosgene-specific fluorescent probes, providing concise “fast glance” and systematic “big picture” to the related researchers and public safety engineers. Moreover, the outlook in this field was also stated.

A two-dimensional layered metal-organic framework, [Eu(C ₂₆H ₁₅NO ₄)Cl] _n (EuCDDB), was synthesized by the reaction of EuCl ₃·6H ₂O and 4,4'-(9 H-carbazole-3,6-diyl)dibenzoic acid (H ₂CDDB) through one-pot solvothermal process, and characterized by several technologies of single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectrum. The crystal structure reveals that hydrogen bonding interaction happens between NH groups and coordinated chloride ions from the adjacent coordination layers, meanwhile, well-opened one-dimensional channel allows the accommodation of water molecules. These characteristics endow EuCDDB with a considerable proton conductivity of 3.70 × 10 ^-6 S cm ^-1 under 90 °C and relative humidity of 90%. In addition, EuCDDB also exhibits turn-on luminescent sensing on DMF molecules by enhanced Eu ³⁺ red emission resulting from efficient ligand-to-metal energy transfer process.

The authors regret the unnoticed error occurred during the data transmission process while preparing the manuscript. We inadvertently included wrong set of images in Figure 1(A), Figure 3(A&D), Figure 4(A) and Figure 5(A&D) panels of original manuscript. The corrected figure panels are provided below.