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A novel salicylaldehydate linked c-MOF (Fe-Tp) was synthesized through a facile mechano-synthesis. The Fe-Tp showed excellent chemical stability in high-concentration acid (10 M) and outstanding long-term stability in capacitive performance in acid electrolyte (36,000 cycles with 80 % retention of initial capacitance). [Display omitted] • A novel salicylaldehydate-based 3D-conjugated-MOF (Fe-Tp) was constructed. • The structure of Fe-Tp is solved by combining electron diffraction and molecular simulation. • The Fe-Tp exhibited remarkable chemical stability in 10 M acids. • Dynamic electrochemical proton storage was observed in Fe-Tp under varied conditions. • The Fe-Tp-supercapacitor displayed outstanding stability over 36,000 cycles. Conjugated metal–organic frameworks (c-MOFs) are potential candidates for excellent electro and photochemical activities such as energy storage and catalysis. However, the poor chemical stability of c-MOFs obstructs them from the practical utilities in acid or base-functioned energy storage devices. Herein, we have introduced a novel iron-based salicylaldehydate 3D-c-MOF (Fe-Tp) with high chemical stability in strong acid environments. The robust coordination bond between iron and C 3 symmetric salicylaldehyde organic pockets results in a doubly interpenetrated 3D framework with ultra-high chemical stability. The biphasic doubly interpenetrated structure of Fe-Tp was elucidated using theoretical modeling with the assistance of single-crystal electron diffraction analysis. The Fe-Tp showed chemical stability even in 10 M H 2 SO 4 for 24 h. Moreover, we have investigated the dynamic charge storages in Fe-Tp in varying concentrations of acid electrolyte (122 F g−1 at 0.1 M H 2 SO 4 to 400 F g−1 at 5 M H 2 SO 4 at 0.1 A/g). The Fe-Tp-based flexible quasi-solid-state supercapacitor was fabricated using proton-loaded PVA electrolyte gel. It showed an excellent electrode capacitance of 106.25 mF cm−2 (at 0.25 mA cm−2) with remarkable cyclic stability (36,000 cycles with 80 % capacitance retention at 5 mA cm−2). [ABSTRACT FROM AUTHOR]

Efficient enzyme immobilization is crucial for the successful commercialization of large-scale enzymatic water treatment. However, issues such as lack of high enzyme loading coupled with enzyme leaching present challenges for the widespread adoption of immobilized enzyme systems. The present study describes the development and bioremediation application of an enzyme biocomposite employing a cationic macrocycle-based covalent organic framework (COF) with hierarchical porosity for the immobilization of horseradish peroxidase (HRP). The intrinsic hierarchical porous features of the azacalix[4]arene-based COF (ACA-COF) allowed for a maximum HRP loading capacity of 0.76 mg/mg COF with low enzyme leaching (<5.0 %). The biocomposite, HRP@ACA-COF, exhibited exceptional thermal stability (∼200 % higher relative activity than the free enzyme), and maintained ∼60 % enzyme activity after five cycles. LCMSMS analyses confirmed that the HRP@ACA-COF system was able to achieve > 99 % degradation of seven diverse types of emerging pollutants (2-mercaptobenzothiazole, paracetamol, caffeic acid, methylparaben, furosemide, sulfamethoxazole, and salicylic acid)in under an hour. The described enzyme-COF system offers promise for efficient wastewater bioremediation applications. [Display omitted] • The hierarchical COF is successfully utilized to achieve high enzyme loading. • The system minimized enzyme leaching and maximized stability/reusability. • For the first time, the HRP is explored as an oxidizing enzyme in biocomposites. • The biocomposite showed catalytic degradation of multiple emerging pollutants. • The work encourages the development of more sustainable water treatment materials. [ABSTRACT FROM AUTHOR]

• A novel mixed matrix membrane was fabricated using a functional 3D-COF pillar. • The functional defects in 3D-COF aids the uniform blending within a membrane. • The presence of COF improved the porosity and mechanical strength of the membrane. • A significant improvement in water flux was observed in presence of the COF pillar. • The membrane showed excellent phenol removal even in harsh conditions. The membrane-based separation of molecular pollutants has several advantages such as minimum energy utilization, recyclability, and commercial viability. However, the membrane fabrications should be in line with the suitable porosity, functionality, mechanical strength, and economical for their practical applications. Herein, we report a novel hybrid membrane (TamDbta-CA) of low-cost cellulose acetate (CA) polymer and functionally diverse porous defective 3D-COF (TamDbta) for the removal of toxic phenol from industrially relevant synthetic oil-produced water. The low percentage (0.8%) use of TamDbta as pillars in CA-membranes improved the porosity, hydrophilicity, mechanical strength, and separation efficiency of phenol (∼80 to 90 %). The defective functional sites (–C=O and –Br) and nanoporosity of TamDbta and its uniform distribution throughout the mixed-matrix membrane contributed to the enhancement of membrane performance. The strategic membrane design and its efficient use for removing toxic pollutants may pave the way for using COFs as a pillar in commercially viable membranes. [ABSTRACT FROM AUTHOR]

Using first-principles method, surface energies of crystal planes of different tantalum carbide phases have been calculated. Quantum size effects are shown to possibly play a considerable role in determining accurate surface energies of these metallic films, which have been neglected in previous works. The γ-TaC phase has a more stable (0 0 1) surface than the close-packed (1 1 1) surface. In the α-Ta 2 C phase, (0 0 1) surface with only Ta termination is more stable than that of mixed Ta-C termination because the metallic bonds between Ta atoms are weaker than the Ta-C covalent bonds. The same is true for the ζ-Ta 4 C 3 phase. The introduction of structural vacancies in the ζ-Ta 4 C 3 − x phase creates more direct Ta metallic bonds, making the Ta-terminated surfaces even more stable. This is consistent with the experimental observations of cleavage of the basal planes, lamellae bridging of cracks, and the high fracture toughness of ζ-Ta 4 C 3 − x . [ABSTRACT FROM AUTHOR]

Abstract: Fully-dense, polycrystalline yttria (Y2O3) exhibits high infrared (IR) transmittance in the full mid range (3–5µm) with low emittance, but lacks thermal-shock resistance for high-performance aerospace applications due to its low strength and high coefficient of thermal expansion (CTE). An attempt was made to develop a low CTE and high strength composite of Y2O3 by dispersing the phase, Y2W3O12, known to exhibit a high negative CTE. The sintered mixture of Y2O3 and Y2W3O12, however, does not form a stable, two-phase composite. The sintered mixture forms new Y2O3-rich phases, such as Y2WO6 and Y6WO12, depending on the relative amounts of Y2O3 and WO3. Investigation of the thermal-expansion behaviors of these yttrium tungstates revealed that they have high CTEs comparable to pure Y2O3. The goal of obtaining a near-zero CTE composite with Y2O3 as the matrix and a yttrium tungstate with a negative CTE as the dispersed phase cannot be realized in this system. [Copyright &y& Elsevier]

Abstract: The imaging of hypoxia is important for therapeutic decision making in various diseases. 68Ga is an important radionuclide for positron emission tomography (PET), and its usage is increasing, due to the development of the 68Ge/68Ga-generator. In the present study, the authors synthesized two nitroimidazole derivatives by conjugating nitroimidazole and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) via an amide bond (4) and a thiourea bond (5). Both derivatives were labeled with 68Ga with high labeling efficiency and were stable after labeling. The low partition coefficients (log P) of 68Ga-4 (−4.6) and 68Ga-5 (−4.5) demonstrated the hydrophilic natures of the derivatives, and both showed higher uptake in cancer cell lines cultured under hypoxic condition than under normoxic condition. However, 68Ga-5 showed higher liver uptake than 68Ga-4 in a biodistribution study due to higher lipophilicity. In an animal PET study, 68Ga-4 showed higher standard uptake values (SUV) in tumors than 68Ga-5 in mice xenografted with CT-26 mouse colon cancer cells. [Copyright &y& Elsevier]

Lithium-sulfur (Li─S) batteries are an attractive option for future energy storage devices because they offer higher theoretical specific capacity, energy density, and cost-effectiveness than commercial lithium-ion batteries. However, the practical applications of Li─S batteries are significantly limited by the shuttle effect caused by intermediate lithium polysulfides (LiPSs) and slow redox kinetics. In this study, the molecular engineering of chalcone-linked, sp 2 -bonded nanographene-type covalent organic frameworks (COFs) as sulfur hosts is reported to enhance interactions with LiPSs, thereby effectively suppressing the shuttle effect. The developed sulfur-hosting cathode material demonstrated outstanding battery performance, surpassing most reported materials by achieving a specific capacity of 1228 mA h g -1 at 0.5C, with 80% retention after 500 cycles and an average Coulombic Efficiency (C.E.) of 99%. Additionally, the mechanisms of sulfur immobilization, the subsequent conversion into lithium polysulfides (LiPSs), and their binding energies with COFs are investigated using density functional theory (DFT) calculations. These findings offer valuable insights into the structure-property relationships essential for developing more efficient sulfur-hosting cathodes., (© 2025 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Suzuki-Miyaura coupling (SMC), a crucial C-C cross-coupling reaction, is still associated with challenges such as high synthetic costs, intricate work-ups, and contamination with homogeneous metal catalysts. Research intensely focuses on strategies to convert homogeneous soluble metal catalysts into insoluble powder solids, promoting heterogeneous catalysis for easy recovery and reuse as well as for exploring greener reaction protocols. Metal-Organic Frameworks (MOFs), recognized for their high surface area, porosity, and presence of transition metals, are increasingly studied for developing heterogeneous SMC. The molecular fence effect, attributed to MOF surface functionalization, helps preventing catalyst deactivation by aggregation, migration, and leaching during catalysis. Recent reports demonstrate the enhanced catalytic activity, selectivity, stability, application scopes, and potential of MOFs in developing greener heterogeneous synthetic methodologies. This review focuses on the catalytic applications of MOFs in SMC reactions, emphasizing developments after 2016. It critically examines the synthesis and incorporation of active metal species into MOFs, focusing on morphology, crystallinity, and dimensionality for catalytic activity induction. MOF catalysts are categorized based on their metal nodes in subsections, with comprehensive discussion on Pd incorporation strategies, catalyst structures, optimal SMC conditions, and application scopes, concluding with insights into challenges and future research directions in this important emerging area of MOF applications., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Conflict statement., (© 2024 The Authors.)

The charge-trapping mechanism in conjugated polymers is a performance obstacle in many optoelectronic devices harnessed for non-volatile memory applications. Herein, a carbonyl-decorated organic 2D-polymer (TpDb)-based charge-trapping memory device has been developed with a wide memory window (3.2 V) with low programming and erasing voltages of +3/-2 and -3/+2. The TpDb was synthesized by a potentially scalable solid-state aldol condensation reaction. The inherent structural defects and the semi-conjugated nature of the enone network in TpDb offer effective charge-trapping through the localization of charges in specific functional groups (CO). The interlayer hydrogen bonding enhances the packing density of the 2D-polymer layers thereby improving the memory storage properties of the material. Furthermore, the TpDb exhibits excellent features for non-volatile memory applications including over 10 000 cycles of write/read endurance and a prolonged retention performance of 10 4 seconds at high temperatures (100 °C).

Covalent organic frameworks (COFs) are two-dimensional, crystalline porous framework materials with numerous scopes for tunability, such as porosity, functionality, stability and aspect ratio (thickness to length ratio). The manipulation of π-stacking in COFs results in truly 2D materials, namely covalent organic nanosheets (CONs), adds advantages in many applications. In this Minireview, we have discussed both top-down (COFs→CONs) and bottom-up (molecules→CONs) approaches with precise information on thickness and lateral growth. We have showcased the research progress on CONs in a few selected applications, such as batteries, catalysis, sensing and biomedical applications. This Minireview specifically highlights the reports where the authors compare the performance of CONs with COFs by demonstrating the impact of the thickness and lateral growth of the nanosheets. We have also provided the possible scope of exploration of CONs research in terms of inter-dimensional conversion, such as graphene to carbon nanotube and future technologies., (© 2024 Wiley-VCH GmbH.)

ConspectusOne-dimensional organic nanotubes feature unique properties, such as confined chemical environments and transport channels, which are highly desirable for many applications. Advances in synthetic methods have enabled the creation of different types of organic nanotubes, including supramolecular, hydrogen-bonded, and carbon nanotube analogues. However, challenges associated with chemical and mechanical stability along with difficulties in controlling aspect ratios remain a significant bottleneck. The fascination with structured porous materials has paved the way for the emergence of reticular solids such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and organic cages. Reticular materials with tubular morphology promise architectural stability with the additional benefit of permeant porosity. Despite this, the current synthetic approaches to these reticular nanotubes focus more on structural design resulting in less reliable morphological uniformity. This Account, highlights the design motivation behind various classes of organic nanotubes, emphasizing their porous interior space. We explore the strategic assembly of organic nanotubes based on their bonding characteristics, from weak supramolecular to robust covalent interactions. Special attention is given to reticular nanotubes, which have gained prominence over the past two decades due to their distinctive micro and mesoporous structures. We examine the synergy of covalent and noncovalent interactions in constructing assembly of these nanotube structures.This Account furnishes a comprehensive overview of our efforts and advancements in developing porous covalent organic nanotubes (CONTs). We describe a general synthetic approach for creating robust imine-linked nanotubes based on the reticular chemistry principles. The use of spatially oriented tetratopic triptycene-based amine and linear ditopic aldehyde building blocks facilitates one-dimensional nanotube growth. The interplay between directional covalent bonds and solvophobic interactions is crucial for forming uniform, well-defined, and high aspect ratio nanotubes. The nanotubes derive their permeant porosity and thermal and chemical stability from their covalent architecture. We also highlight the adaptability of our synthetic methodology to guide the transformation of one-dimensional nanotubes to toroidal superstructures and two-dimensional thin fabrics. Such morphological transformation can be directed by tuning the reaction time or incorporating additional intermolecular interactions to control the intertwining behavior of individual nanotubes. The cohesion of covalent and noncovalent interactions in the tubular nanostructures manifests superior viscoelastic mechanical properties in the assembled CONT fabrics. We establish a strong correlation between structural framework design and nanostructures by translating reticular synthesis to morphological space and gaining insights into the assembly processes. We anticipate that the present Account will lay the foundation for exploring new designs and chemistry of organic nanotubes for many application platforms.

Fluorescent covalent organic frameworks (COFs) have emerged as promising candidates for imaging living cells due to their unique properties and adjustable fluorescence. In this mini-review, we provide an overview of recent advancements in fluorescent COFs for bioimaging applications. We discuss the strategies used to design COFs with desirable properties such as high photostability, excellent biocompatibility, and pH sensitivity. Additionally, we explore the various ways in which fluorescent COFs are utilized in bioimaging, including cellular imaging, targeting specific organelles, and tracking biomolecules. We delve into their applications in sensing intracellular pH, reactive oxygen species (ROS), and specific biomarkers. Furthermore, we examine how functionalization techniques enhance the targeting and imaging capabilities of fluorescent COFs. Finally, we discuss the challenges and prospects in the field of fluorescent COFs for bioimaging in living cells, urging further research in this exciting area.

Covalent organic frameworks (COFs) have been used in cell imaging, but very rarely for imaging specific cell conditions. Herein, a β-ketoenamine-based fluorescent COF was post-synthetically modified to incorporate a hypoxia-targeting molecule. Fluorescence microscopy imaging shows that the material discriminates between HeLa cells grown under hypoxia and those cultured under normoxia.

Photocatalytic CO 2 reduction into formate (HCOO - ) has been widely studied with semiconductor and molecule-based systems, but it is rarely investigated with covalent organic frameworks (COFs). Herein, we report a novel donor-acceptor COF named Co-PI-COF composed of isoindigo and metallated porphyrin subunits that exhibits high catalytic efficiency (∼50 μmol formate g -1 h -1 ) at low-power visible-light irradiation and in the absence of rare metal cocatalysts. Density functional theory calculations and experimental diffuse-reflectance measurements are used to explain the origin of catalytic efficiency and the particularly low band gap (0.56 eV) in this material. The mechanism of photocatalysis is also studied experimentally and is found to involve electron transfer from the sacrificial agent to the excited Co-PI-COF . The observed high-efficiency conversion could be ascribed to the enhanced CO 2 adsorption on the coordinatively unsaturated cobalt centers, the narrow band gap, and the efficient transfer of the charge originating from the postsynthetic metallation. It is anticipated that this study will pave the way toward the design of new simple and efficient catalysts for photocatalytic CO 2 reduction into useful products.

Two calix[4]arene systems, C23 4+ and C24 4+ - where 2 corresponds to the number of viologen units and 3-4 corresponds to the number of carbon atoms connecting the viologen units to the macrocyclic core - have been synthesized and led to the formation of [3]pseudorotaxanes when combined with either CB[7] or CB[8]. The [3]pseudorotaxanes spontaneously dissociate upon reduction of the bipyridinium units as the result of intramolecular dimerization of the two face-to-face viologen radical cations. CB[7] and CB[8]-based [2]pseudorotaxanes containing monomeric viologen guest model compounds, MC3 2+ and MC 4+ , do not undergo decomplexation and dimerization following electrochemical reduction of their bipyridinium units., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Following the advancements and diversification in synthetic strategies for porous covalent materials in the literature, the materials science community started to investigate the performance of covalent organic polymers (COPs) and covalent organic frameworks (COFs) in applications that require large surface areas for interaction with other molecules, chemical stability, and insolubility. Sensorics is an area where COPs and COFs have demonstrated immense potential and achieved high levels of sensitivity and selectivity on account of their tunable structures. In this review, we focus on those covalent polymeric systems that use fluorescence spectroscopy as a method of detection. After briefly reviewing the physical basis of fluorescence-based sensors, we delve into various kinds of analytes that have been explored with COPs and COFs, namely, heavy metal ions, explosives, biological molecules, amines, pH, volatile organic compounds and solvents, iodine, enantiomers, gases, and anions. Throughout this work, we discuss the mechanisms involved in each sensing application and aim to quantify the potency of the discussed sensors by providing limits of detection and quenching constants when available. This review concludes with a summary of the surveyed literature and raises a few concerns that should be addressed in the future development of COP and COF fluorescence-based sensors.

A new and innovative class of calixarene-based polymers emerged as adsorbents for a variety of compounds and ions in solution and vapor media. These materials take advantage of the modifiable rims and hydrophobic cavities of the calixarene monomers, in addition to the porous nature of the polymeric matrix. With main-chain calixarenes' function as supramolecular hosts and the polymers' high surface areas, polycalixarenes can effectively encapsulate target analytes. This feature is particularly useful for environmental remediation as dangerous and toxic molecules reversibly bind to the macrocyclic cavity, which facilitates their removal and enables repeated use of the polymeric sorbent. This Spotlight touches on the unique characteristics of the calixarene monomers and discusses the synthetic methods of our reported calixarene-based porous polymers, including Sonogashira-Hagihara coupling, and diazo and imine bond formation. It then discusses the promising applications of these materials in adsorbing dyes, micropollutants, iodine, mercury, paraquat, and perfluorooctanoic acid (PFOA) from water. In most cases, these reports cover materials that outperform others in terms of recyclability, rates of adsorption, or uptake capacities of specific pollutants. Finally, this Spotlight addresses the current challenges and future aspects of utilizing porous polymers in pollution treatment.

A bowl-shaped calix[4]arene with its exciting host-guest chemistry is a versatile supramolecular building block for the synthesis of distinct coordination cages or metal-organic frameworks. However, its utility in the synthesis of crystalline covalent organic frameworks (COFs) remains challenging, presumably due to its conformational flexibility. Here, we report the synthesis of a periodic 2D extended organic network of calix[4]arenes joined by a linear benzidine linker via dynamic imine bonds. By tuning the interaction among neighboring calixarene units through varying the concentration in the reaction mixture, we show the selective formation of interpenetrated (CX4-BD-1) and non-interpenetrated (CX4-BD-2) frameworks. The cone-shaped calixarene moiety in the structural backbone allows for the interweaving of two neighboring layers in CX4-BD-1, making it a unique example of interpenetrated 2D layers. Due to the high negative surface charge from calixarene units, both COFs have shown high performance in charge-selective dye removal and an exceptional selectivity for cationic dyes irrespective of their molecular size. The charge distribution of the COFs and the resulting selectivity for the cationic dyes were further investigated using computational methods.

On account of its nonbiodegradable nature and persistence in the environment, perfluorooctanoic acid (PFOA) accumulates in water resources and poses serious environmental issues in many parts of the world. Here, we present the development of two fluorine-rich calix[4]arene-based porous polymers, FCX4-P and FCX4-BP , and demonstrate their utility for the efficient removal of PFOA from water. These materials featured Brunauer-Emmett-Teller (BET) surface areas of up to 450 m 2 g -1 , which is slightly lower than their nonfluorinated counterparts (up to 596 m 2 g -1 ). FCX4-P removes PFOA at environmentally relevant concentrations with a high rate constant of 3.80 g mg -1 h -1 and reached an exceptional maximum PFOA uptake capacity of 188.7 mg g -1 . In addition, it could be regenerated by simple methanol wash and reused without a significant decrease in performance.

The presence of carcinogenic bromate (BrO 3 - ) in drinking water became a global concern and efforts towards its removal mainly focused on addressing the source. Herein, we rationally designed a porphyrin-based covalent organic framework ( PV-COF ) with a cationic surface to provide electrostatic interactions and a porphyrin core to induce hydrogen bonding interactions for the efficient removal of BrO 3 - from water. Through H-bonding and electrostatic interactions, PV-COF exhibited an exceptional bromate removal efficiency (maximum adsorption capacity, Q max : 203.8 mg g -1 ) with the fastest uptake rate ( k ads ) of 191.45 g mg -1 min -1 . The bromate concentration was reduced to far below the allowed concentration in drinking water (10 ppb) within 20 minutes. We studied the relationship between bromate adsorption and COF surface modification by metalation of the porphyrinic core or neutralization of the viologen linkers by chemical reduction. The bromate adsorption mechanism was studied by EDAX mapping and molecular simulations, and it was found that ion exchange and hydrogen bonding formation drive the adsorption. Importantly, PV-COF could be easily recycled several times without compromising its adsorption efficiency., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Here we report template-free synthesis of imine-linked calix[4]arene hollow nanocapsules and their utility in the effective delivery of a poorly soluble cancer drug into tumor cells. These stimuli-responsive nanocapsules show high drug loading and release which resulted in a 40-fold higher cytotoxicity for breast cancer cell line over normal cells.

A rational design of adsorbents with high uptake efficiency and fast kinetics for highly toxic pollutants is a key challenge in environmental remediation. Here, we report the design of a well-defined thioether-crown-rich porous calix[4]arene-based mesoporous polymer S-CX4P and its utility in removal of highly relevant toxic mercury (Hg 2+ ) from water. The polymer shows an exceptional, record-high uptake efficiency of 1686 mg g -1 and the fastest initial adsorption rate of 278 mg g -1 min -1 . Remarkably, S-CX4P can effectively remove Hg 2+ from high concentration (5 ppm) to below the acceptable limit for drinking water (2 ppb) even in the presence of other competitive metals at high concentrations. In addition, the polymer can be easily regenerated at room temperature and reused multiple times with negligible loss in uptake rate and efficiency. The results demonstrate the potential of rationally designed thioether-crown-rich polymers for high performance mercury removal.

Dicationic quaternary salts of 4,4'-bipyridine, also referred to as the viologen family, are well-known for their interesting redox chemistry, whereby they can be reversibly reduced into radical cationic and neutral moieties. Because of this ability to switch between different redox states, viologens have frequently been incorporated into covalent organic polymers (COPs) as molecular switches to construct stimuli-responsive materials. Although many viologen-based COPs have been reported, hyper-conjugated insoluble COPs started to emerge fairly recently and have not been comprehensively reviewed. In this review, we investigate the design strategies employed in the synthesis of insoluble viologen-based COPs, which can be broadly classified as those with viologen in the backbone and those with viologen as pendant groups. Chemical reactions used in the synthesis of each category, including Sonogashira-Hagihara cross-coupling, Menshutkin and Zincke reactions, are highlighted. Diverse applications of these COPs are discussed with particular reference to the redox state of viologen in each material. Uses of these materials for gas adsorption, organic and inorganic pollutant removal, catalysis, sensing and film fabrication are explored.

Owing to their chemical and thermal stabilities, high uptake capacities, and easy recyclability, covalent organic polymers (COPs) have shown promise as pollutant sponges. Herein, we describe the use of diazo coupling to synthesize two cationic COPs, COP1 ++ and COP2 ++ , that incorporate a viologen-based molecular switch and an organic macrocycle, calix[4]arene. The COPs form nanosheets that have height profiles of 6.00 nm and 8.00 nm, respectively, based on AFM measurements. The sheets remain morphologically intact upon one- or two-electron reductions of their viologen subunits. MD simulations of the COPs containing dicationic viologens indicate that the calix[4]arenes adopt a partial cone conformation and that, in height, the individual 2D polymer layers are 5.48 Å in COP1 ++ and 5.65 Å in COP2 ++ , which, together with the AFM measurements, suggests that the nanosheets are composed of 11 and 14 layers, respectively. Whether their viologens are in dicationic, radical cationic, or neutral form, the COPs exhibit high affinity for iodine, reaching up to 200 % mass increase when exposed to iodine vapor at 70 °C, which makes the materials among the best-performing nanosheets for iodine capture reported in the literature. In addition, the COPs effectively remove Congo red from solution in the pH range of 2-10, reaching nearly 100 % removal within 15 minutes at acidic pH., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Composites always remained the target of discussion due to lot of controversies around it. Mechanical properties are one of them. With the introduction of new technology and emergence of various composites which combine superior strength and polish retention, nanocomposites have led to a new spark in the dentistry. A recent curing unit LED with various curing modes claims to produce higher degree of conversion. The aim of this study was to evaluate the diametral tensile strength and flexural strength of nanocomposite, hybrid and minifill composites cured with different light sources (QTH vs LED)., Materials and Methods: Seventy-two samples were prepared using different specially fabricated teflon molds, 24 samples of each composite were prepared for the diametral tensile strength (ADA specification no. 27) and the flexural strength (ISO 4049) of the 12 samples, six were cured with LED (Soft Start curing profile) and other six with QTH curing light and tested on a universal testing machine., Results: The nanocomposite had highest diametral tensile strength and flexural strength which were equivalent to the hybrid composite and superior than the minifill composite., Conclusion: With the combination of superior esthetics and other optimized physical properties, this novel nanocomposite system would be useful for all posterior and anterior applications.

We report herein a novel isothiocyanate active ligand for fluorine-18 labeling prepared by four step synthesis. It can be conjugated to a target molecule containing an amino functional group under weak basic conditions by way of thiourea bond formation. We explored the application of synthesized ligand by conjugating to well known α(v)β(3) integrin targeting peptide, c(RGDyK). The conjugated peptide showed good radiochemical yield and efficiency with an excellent radiochemical purity (97.1 ± 1.2%) in a short reaction time (10 min). Labeled peptide showed excellent in vitro and in vivo stability (>95%). α(v)β(3) integrin specific tumor uptake was observed both in biodistribution and small animal microPET studies on α(v)β(3)-positive U87MG (human glioma cells) xenograft bearing mice. In general, successful application of synthesized ligand for labeling of RGD peptide could facilitate the possibility of using this ligand for labeling peptides containing an amino functional group., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Purpose: We evaluated new (111)In-labeled amino acid derivatives, in which the amino acids are conjugated with1,4,7,10-tetra-azacyclododecane-1,4,7,10-tetraacetic acid (DOTA), 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (DO2A) or 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A)., Methods: DOTA-aminoalanine (DOTA-A), DOTA-aminohomoalanine (DOTA-H), DOTA-lysine (DOTA-L), DO2A-alanine (DO2A-A), DO3A-alanine (DO3A-A) and DO3A-homoalanine (DO3A-H) were labeled with (111)In. In vitro cell uptake assays were performed usingHep3B (a human hepatoma cell line), CT26 (a mouse colon cancer cell line) and U87MG (a human glioma cell line). In vitro cell uptake inhibition assays were performed using U87MG and (111)In-DO3A-H. U87MG bearing xenografted mice were subject to biodistribution, SPECT imaging, autoradiography, and immunohistochemistry studies., Results: Of the amino acid derivatives and cell lines examined, U87MG and (111)In-DO3A-H showed highest uptake in vitro. This uptake was blocked by 2-aminobicyclo-[2,2,1] heptane-2-carboxylic acid (BCH) and by tryptophan. (111)In-DO3A-HSPECT imaging of U87MG bearing xenografted mice visualized tumors (mean tumor-to-muscle ratio 3.16±0.74). Autoradiography and immunohistochemistry revealed that (111)In-DO3A-H uptake matched L-type amino acid transporter 1 expression., Conclusion: Tumor uptake was successfully imaged using (111)In-DO3A-H in U87MG bearing xenografted mice. (111)In-DO3A-H appears to be useful for imaging tumors expressing L-type amino acid transporter., (Copyright © 2012 Elsevier Inc. All rights reserved.)

(68)Ga is a promising emerging radionuclide for positron emission tomography (PET). It is produced using a (68)Ge/(68)Ga-generator, and thus, would enable the cyclotron-independent distribution of PET. However, new (68)Ga-labeled radiopharmaceuticals that can replace (18)F-labeled agents like [(18)F]fluorodeoxyglucose (FDG) are needed. Most of the (68)Ga-labeled derivatives currently used are peptide agents, but the developments of other agents, such as amino acid derivatives, nitroimidazole derivatives, and glycosylated human serum albumin, are being actively pursued in many laboratories. Thus, appearance of new (68)Ga-labeled radiopharmaceuticals with high impact are expected in the near future. Here, we present an overview of (68)Ga-labeled agents in terms of their clinical significances and relevances to the management of certain tumors, and pertinent pre-clinical developments.

Objectives: We developed amino acid derivatives of 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (DO2A) and 1,4,7,10-tetraazacyclododecane-1,4,7,-triacetic acid (DO3A) that can be labeled with (68)Ga, and we investigated their basic biological properties., Materials and Methods: Alanine derivatives of DO2A and DO3A were synthesized by regiospecific nucleophilic attack of DO2tBu and DO3tBu on the β-position of Boc-l-serine-β-lactone, followed by acid hydrolysis. Also, homoalanine derivatives were synthesized by reacting with the protected bromo derivative of homoalanine, which was synthesized from N-Cbz-l-homoserine lactone. Further catalytic reduction and acid cleavage of protected groups resulted in the required products. All derivatives were labeled with (68)Ga. Cell uptake assays were carried out in Hep3B (human hepatoma) and U87MG (human glioma) cell lines at 37°C. Positron emission tomography (PET) imaging studies were performed using balb/c mice xenografted with CT-26 (mouse colon cancer)., Results: All compounds were labeled with >97% efficiency. According to in vitro studies, the labeled amino acid derivatives showed significantly greater uptakes than the control ((68)Ga 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) in cancer cells. Small animal PET images for labeled compounds showed high tumor uptake, as well as kidney and bladder uptakes, at 30 min postinjection. (68)Ga-DO3A-homoalanine showed the highest standardized uptake value ratio (3.9 ± 0.3), followed by (68)Ga-DO2A-alanine (3.1 ± 0.2), (68)Ga-DO3A-alanine (2.8 ± 0.2) and (68)Ga-DO2A-homoalanine (2.3 ± 0.2)., Conclusion: These derivatives were found to have high labeling efficiencies, high stabilities, high tumor cell uptakes, high tumor/nontumor xenograft uptakes and low nonspecific uptake in normal organs, except for the kidneys. However, the uptake mechanism of these derivatives remains unclear, and uptake via specific amino acid transporters needs to be demonstrated., (Copyright © 2010 Elsevier Inc. All rights reserved.)

(68)Ga PET imaging in clinical oncology represents a notable development because the availability of (68)Ga is not dependent on a cyclotron. Furthermore, labeled amino acid derivatives have been proven to be useful for the imaging many tumor types. In the present study, we synthesized β-aminoalanine, γ-aminohomoalanine, and lysine conjugates of macrocyclic bifunctional chelating agents, such as, NOTA (1a-c) and DOTA (2a-c). The compounds produced were found to be potential useful as (68)Ga-PET imaging agents. In particular, they showed high tumor uptakes in vitro and in vivo, and had high labeling yields and excellent stabilities. The co-ordination chemistry of NOTA-monoamide compound 1a was studied by multinuclear NMR. In vitro studies showed that the synthesized compounds were taken up by cancer cells more than controls ((68)Ga-NOTA and (68)Ga-DOTA). Furthermore, in vivo studies showed that they have high tumor to muscle and tumor to blood ratios, and small-animal PET imaging revealed high tumor uptakes as compared with other organs, and high bladder activities, indicating rapid renal excretion. These results might motivate the use of (68)Ga amino acid PET for tumor diagnosis., (Copyright © 2010 Elsevier Ltd. All rights reserved.)