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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

In the photovoltaic field, perovskite solar cells (PSCs) are gaining momentum due to the implementation of interface and additive engineering as viable approaches to advance commercialization. Our review begins with an outline of the latest progress in PSCs, followed by essential background information. The primary focus is on recent studies of small molecules and ionic liquids employed in interface and additive engineering to enhance device stability and performance. Ferrocenyl-bis-thio- phene-2-carboxylate (FcTc ₂) and 3,4-bis(4-bromophenyl)-cyclobut-3-ene-1,2-dione (BED) belong to interface engineering, while 3-ethylbenzo[ b]thiophene-1,1-dioxide (PSAD), 1-bromo-4-(methylsulfinyl) benzene (BMMS), 1-(4-bromophenyl)-6,7-diphenylimidazo indolizine (PDPII) and 9-bromo-6,7-diphenyl- pyrido[2,1- a]isoquinolin-5-ium hexafluoro-phosphate (DPPIQ ⁺PF ₆ ^-), utilized in our previous research, are part of additive engineering. These studies centered around the potential interactions between additives and perovskites and the mechanisms these compounds minimize or passivate defects. Our aim with this review is to shed light on these findings and inspire continued theoretical and experimental investigations.

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.

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.

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.

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.

Visible-light mediated photoinduced reversible deactivation radical polymerization (RDRP) is a promising method for producing well-defined polymers; however, it typically requires metal-containing catalysts, which can be toxic and limit practical applications. Therefore, developing new RDRP techniques is crucial. One promising approach is visible-light mediated photoinduced atom transfer radical polymerization (photoATRP), which utilizes metal-free photocatalysts and eco-friendly light to catalyze polymerization. PhotoATRP offers more precise control over polymerization kinetics and can be performed in diverse solvents, including water, enhancing versatility and enabling the production of polymers with well-defined structures, low molecular weight distribution indexes, and controllable relative molecular weights. This minireview outlines recent advances on photoATRP using metal-free quantum dots (QDs) as photocatalysts. The research progress and influence factors for QDs-based photoATRP, as well as the mechanistic insights into the process, were discussed. Finally, we address the challenges and opportunities facing QDs-based photoATRP.

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.

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.

One-dimensional (1D) Al-doped V ₂O ₅ nanowires were synthesized by a hydrothermal method and subsequent heat treatment process. The microstructure, surface morphology, and electrochemical performance of the as-prepared 1D Al-doped V ₂O ₅ nanowires were analyzed by XRD, XPS, SEM, CV, EIS, and galvanostatic discharge/charge tests. The results show that Al ³⁺ doping can effectively increase the V ⁴⁺ concentration in V ₂O ₅ material and prevent the agglomeration of V ₂O ₅ nanowires. When used as a cathode material for lithium-ion batteries (LIBs), the Al-doped V ₂O ₅ sample exhibits much-enhanced cycling performance, improved high-rate capability, higher electrochemical reaction reversibility, and lower electrochemical reaction resistance than the pure V ₂O ₅ sample (without Al ³⁺ doping).

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.

Among best known semiconductor quantum dots (QDs) are CdSe/ZnS core/shell nanostructures, whose much enhanced photoexcited state properties over those of uncapped CdSe nanoparticles are rationalized in the literature such that “the ZnS capping with a higher bandgap than CdSe passivates the core crystallite removing the surface traps”. In this work, the method commonly employed in the ZnS capping of CdSe for CdSe/ZnS QDs was applied to the same capping of small carbon nanoparticles (CNPs) for CNP/ZnS core/shell nanostructures, which are conceptually and configuration-wise equivalent to the replacement of the semiconductor (CdSe) core with CNP in the classical core/shell QDs. The fluorescence emission properties of CNP/ZnS core/shell nanostructures were found to be similar to those of organic functionalized CNPs in classically defined carbon dots (CDots), both dramatically enhanced from those of “naked” CNPs in solvent dispersions. Mechanistic implications of the findings are discussed.