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The purification of isomer monomers with high purity is extremely important, particularly in the fine chemical industry, pharmaceutical industry, and so on. Herein, a selective cocrystallization (SCoC) technology based on non-covalent interactions between the target compound and cocrystal conformers was developed to effectively separate isomer mixtures. The unique and efficient selectivity nature of conformers and the general applicability of the selective cocrystallization method was tested through separating and purifying cresol isomer mixtures, pyridinecarboxamide isomer mixtures, and cis−/trans-butenedioic acid mixtures. Moreover, the nature of selective recognition to cocrystallize was confirmed both in the solution and solid states. Thus, this study demonstrates the feasibility of this novel SCoC technology, which is a new method for separating isomer mixtures.

A series of hexadecylphosphate acid (HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/water with the catalysts as stabilizers. With the HDPA-Fe2O3/Al2O3 as the basic catalyst, a series of transition metals, such as Mn, Co, Ni, Cu, Cr, Mo, V, and Ti, was respectively doped to the basic catalyst to modify the performance of the catalytic system, in expectation of influencing the mobility of the lattice oxygen species in the oxide catalysts. Under normally working conditions of the catalytic system, the nanoparticles of catalysts located themselves at the interface between the oil and water phases, constituting the Pickering emulsion. Both the doped iron oxide and its surface adsorbed hexadecylphosphate molecules were essential to the catalytic system for excellent performances with high toluene conversions as well as the exclusive selectivity to benzaldehyde. Under optimal conditions, ∼83% of toluene conversion and >99% selectivity to benzaldehyde were obtained, using molecular oxygen as oxidant and HDPA-(Fe2O3-NiO)/Al2O3 as the catalyst. This process is green and low cost to produce high quality benzaldehyde from O2 oxidation of toluene.

A novel method for the Rh(III)-catalyzed oxime-directed C–H amidation of indoles with dioxazolones has been developed. This strategy provides an exclusive site selectivity and the directing group can be easily removed. This transformation features a wide substrate scope, good functional group tolerance and excellent yields, and may serve as a significant tool to construct structurally diverse indole derivatives for the screening of potential pharmaceuticals in the future.

To investigate the effect of positional isomerism on cocrystallization and reveal the role of weak interactions in the formation of cocrystals, experimental characterization complemented with theoretical computations was thoroughly conducted by using p-hydroxybenzoic acid (PHBA), o-hydroxybenzoic acid (OHBA), m-hydroxybenzoic acid (MHBA) and malonic acid (MA) as model compounds. Selective formation of a new cocrystal was discovered between PHBA and MA molecules via several methods, while no cocrystal was formed between OHBA/MHBA and MA molecules. The PHBA–MA cocrystal was thoroughly characterized and analyzed through several solid characterization techniques such as powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) analysis, Fourier transform infrared (FTIR) spectroscopy, single crystal X-ray diffraction (SCXRD), etc. Taking advantage of a myriad of computational modelling techniques, the molecular recognition mechanism which drove the formation of cocrystals was comprehensively investigated and understood at a molecular level. The structural change accompanied by the cocrystal formation could be rationalized by FTIR spectroscopy and electron density variation analysis. Hirshfeld surface (HS) analysis indicated that O–H⋯O hydrogen bonds played a critical role in the formation of this cocrystal. Molecular electrostatic potential (MESP) surface analysis was employed to predict the interaction sites for cocrystallization, which were in good accordance with the experimental results. Moreover, possible reasons for the selective cocrystallization were analyzed and proposed.

The consistency and variability as well as self-assembly evolution mechanism of cresol–piperazine cocrystals are investigated by experiments and molecular simulation., The disposition of functional groups can induce variations in the nature and type of interactions and hence affect the molecular recognition and self-assembly mechanism in cocrystals. To better understand the formation of cocrystals on a molecular level, the effects of disposition of functional groups on the formation of cocrystals were systematically and comprehensively investigated using cresol isomers (o-, m-, p-cresol) as model compounds. Consistency and variability in these cocrystals containing positional isomers were found and analyzed. The structures, molecular recognition and self-assembly mechanism of supramolecular synthons in solution and in their corresponding cocrystals were verified by a combined experimental and theoretical calculation approach. It was found that the heterosynthons (heterotrimer or heterodimer) combined with O—H⋯N hydrogen bonding played a significant role. Hirshfeld surface analysis and computed interaction energy values were used to determine the hierarchical ordering of the weak interactions. The quantitative analyses of charge transfers and molecular electrostatic potential were also applied to reveal and verify the reasons for consistency and variability. Finally, the molecular recognition, self-assembly and evolution process of the supramolecular synthons in solution were investigated. The results confirm that the supramolecular synthon structures formed initially in solution would be carried over to the final cocrystals, and the supramolecular synthon structures are the precursors of cocrystals and the information memory of the cocrystallization process, which is evidence for classical nucleation theory.

Palladium-catalyzed arylation of unactivated β-C(sp3)-H bonds in carboxylic acid derivatives with aryl iodides is described for the first time using 2-amino-5,6-difluorophenyl-1H-pyrazole as an efficient and readily removable directing group. Two fluoro groups are installed at the 5- and 6-position of the anilino moiety in 2-aminophenyl-1H-pyrazole, clearly enhancing the directing ability of the auxiliary. In addition, the protocol employs Cu(OAc)2/Ag3PO4 (1.2/0.3) as additives, evidently reducing the stoichiometric amount of expensive silver salts. Furthermore, this process exhibits high β-site selectivity, compatibility with diverse substrates containing α-hydrogen atoms, and excellent functional group tolerance.

In this work, to simultaneously remove organic dyes and Pb(II) from wastewater, a series of magnetic Fe3O4@C@TiO2-nanotube composites were designed and successfully synthesized via a new facile oil-phase cyclic magnetic adsorption (OCMA) method. The structural properties of the synthesized composites were investigated by different characterization methods systematically. It was found that Fe3O4 was uniformly deposited on the inner walls of TiO2 nanotubes. Although a Type III band alignment was formed in the catalysts, Fe3O4@C@TiO2-nanotube composites exhibited enhanced light absorbing ability and enlarged absorption edge due to efficient separation of h+ and e−, which was verified by UV–Vis (Ultraviolet–visible) and PL (Photoluminescence) spectra. Decontamination experiments of 1FeCTi showed that more than 98% of RhB and about 92% of Pb(II) ions could be removed through adsorptive removal in the dark equilibrium period and further elimination during the illuminating period. The pseudo-first-order model, L-H model and adsorption-reaction model were established to describe the adsorption of Pb(II) in the dark, photodegradation of RhB and further elimination of Pb(II), respectively. A four-step mechanism was proposed to describe the decontamination process of Pb(II) during the illuminating period according to the final forms of Pb (Pbδ1, Pbδ2, Pb0 and PbO). Finally, it was found that the photocatalytic activity would be maintained in the recycle experiments due to the existence of 1FeCTi@PbO heterostructure.

In this work, to help the development and design of separation and purification processes for tris-(2,4-ditert-butylphenyl)-phosphite which is an antioxidant of plastic processing, its solution thermodynamics was investigated. Using a static gravimetric method, solubilities of tris-(2,4-ditert-butylphenyl)-phosphite in twelve pure solvents (including acetone, ethyl acetate, methyl acetate, ethyl formate, isopropyl acetate, butyl acetate, n-hexane, n-heptane, n-octane, isooctane, propyl acetate and ethyl butyrate) were measured at temperatures varying from 278.15 K to 323.15 K. It was found that, in all investigated solvents, the solubility data of tris-(2,4-ditert-butylphenyl)-phosphite increased with the increasing of temperature over the entire investigated temperature range. The modified Apelblat equation, the λh equation and the NRTL model were employed to correlate the solubility data. The computed data showed that the modified Apelblat equation correlated the solubility data better. Moreover, the mixing and dissolution thermodynamic properties of tris-(2,4-ditert-butylphenyl)-phosphite in various pure solvents were also calculated according to the NRTL model and the experimental solubility data.

A novel route for tandem C-C/C-N formation via palladium-catalyzed C-H activation/styrenation and annulation of O-methylketoxime with styrenes to synthesize benzothienopyridines and benzofuropyridines has been developed. Furthermore, the intermolecular alkenylation of the ketoxime with acrylates produces 3-alkenyl O-methylketoximes in good to excellent yields. The method features mild reaction conditions and good functional group tolerance, providing a direct approach for the preparation of fused heterocycles.

To gain further insights into the formation of cocrystals, the thermodynamic mechanism and molecular recognition process of cocrystal formation were investigated by using p-hydroxybenzoic (PHBA) as the model compound. One new 1 : 1 (molar ratio) cocrystal of p-hydroxybenzoic (PHBA) and glutaric acid (GA) was successfully synthesized via several methods, including liquid-assisted grinding, cooling crystallization, and slurry conversion crystallization. The prepared cocrystal powder was characterized by PXRD, DSC and Raman spectroscopy. The crystal structure of the cocrystal was determined and interpreted by single-crystal XRD. The ternary phase diagrams of the newly prepared cocrystal were constructed in acetonitrile at three temperatures, i.e., 2, 20 and 40 °C. The temperature was shown to have an impact on the shape of the ternary phase diagrams. Guided by the determined ternary phase diagrams, the pure PHBA–GA cocrystal could be prepared successfully by isothermal slurry conversion crystallization. Raman spectroscopy was employed to monitor the molecular recognition and self-assembly process of the conversion in situ. In addition, density functional theory calculations were conducted to determine the stability and interaction energy of the cocrystal, rationalizing the formation potential of the PHBA–GA cocrystal.

A series of tetraphenylethene-borondipyrromethene (TPE-BODIPY) derivatives with different numbers of methyl groups on BODIPY cores were designed and synthesized. The intramolecular charge transfer behaviors from donor TPE to accepter BODIPY were investigated. Aggregation-induced emission (AIE), theoretical calculation, single crystal structure and solvent effect all proved that the introduction of methyl group to BODIPY can inhibit the intramolecular charge transfer behavior. Red organic luminescent material 8-TPEBODIPY (TPB) with no methyl groups showing twisted intramolecular charge transfer (TICT) emission peak both in solution and in film state, presents obviously AIE and solvatochromic properties and a large Stokes shifts over 100 nm, which can be employed as a fluorescent sensor for the detection of water in THF.

Background: In the pharmaceutical field, it is vital to ensure a consistent product containing a single solid-state form of the active pharmaceutical ingredient (API) in the drug product. However, some APIs are suffering from the risk of transformation of their target forms during processing, formulation and storage. Methods: The purpose of this review is to summarize the relevant category of excipients and demonstrate the availability and importance of using excipients as a key strategy to manipulate pharmaceutical polymorphic transformation. Results: The excipient effects on solvent-mediated phase transformations, solid-state transitions and amorphous crystallization are significant. Common pharmaceutical excipients including amino acids and derivatives, surfactants, and various polymers and their different manipulation effects were summarized and discussed. Conclusion: Appropriate use of excipients plays a role in manipulating polymorphic transformation process of corresponding APIs, with a promising application of guaranteeing the stability and effectiveness of drug dosage forms.

Lifespan is a comprehensive indicator of health. Medium and long chain triacylglycerol (MLCT) is an emerging functional product, while there are two types of MLCT (physical mixtures of MCTs and LCTs (MCT/LCT), synthetically structured triglycerides (STG)) with similar fatty acids composition. The two compounds were reported to be associated with some positive benefits in health, while the underlying mechanism is still unclear. Here, it was presented that MCT/LCT could reduce the life span, superoxide dismutase (SOD) activity and catalase (CAT) activity of Caenorhabditis elegans (C. elegans), and increase the total lipid content, the reactive oxygen species (ROS), the MDA and the transcription levels of aak-2, sod-3 and cat-1 when compared with STG group. Further mutant C. elegans experiment proved that the aak-2 pathway is the key for MLCT-modified life span. The different performance of MCT/LCT and STG in life span might result from their inner structure diversity. Overall, our study may have important implications in using specific MLCT to promote healthy aging and designing targeted lipid for individual health.

Hydrogen-bonded frameworks (HOFs), which are constructed from organic moieties via hydrogen bonding, represent an emerging attractive class of porous crystalline materials. Though HOFs have exhibited varieties of merits such as solution processability, highly-crystalline structure, good recyclability, easy purification etc., the flexible and weak feature of hydrogen bonds usually makes the HOFs vulnerable and difficult to maintain the permanent porosity, which greatly hampers the development and application of this kind of materials. In this work, some basic rules to construct HOFs with permanent porosity and good stability are summarized. Moreover, the major applications of HOFs are highlighted in this review, including the gas storage/separation, proton conduction, catalysis, luminescent materials, biotechnology etc. Specifically, some latest developments and discoveries in this area are summarized and discussed. Finally, the promising perspectives of HOFs are also discussed and the potential directions for future work are suggested.

In this work, solubility data of ceftezole in seven pure solvents and two binary solvent systems were experimentally measured via a static gravimetric method in the temperature range from 278.15 K to 313.15 K under atmospheric pressure. The results indicated that the solubility of ceftezole in all the selected pure and binary solvent systems increased with the rising of temperature. It was also found that the solubility order of ceftezole in the seven mono-solvents was generally ranked as: water

The solubility data of cefradine in different solvent systems as a function of pH were determined by dynamic method. The effect of pH and solvent compositions on the solubility data and the isoelectric points were evaluated and discussed. It was found that the solubility data of cefradine are consistent with the dissolution property of ampholyte, whether in mono-solvent or binary mixed solvent, which has a large solubility at large pH and small pH values and the solubility curves exhibit U shapes. The isoelectric points of cefradine in different solvent systems were also determined and discussed. Two theoretical models were used to correlate the experimental solubility data. It was found that model I can give better correlation results.

An efficient and simple method, depositing nano iron oxide onto the surface of Pd/SiO2, to construct sintering-resistant Pd nanocatalysts was presented. The introduction of nano iron oxide not only promoted the sintering-resistance of Pd nanoparticles, but also increased the boundary between the Pd and iron oxide. The resultant catalysts exhibited enhanced catalytic activity for aerobic oxidation of benzyl alcohol.

In this work, solution thermodynamic properties including solubility, mixing thermodynamic properties and dissolution thermodynamic properties are investigated in detail. Gravimetric method was utilized for measuring the solubility data of flurbiprofen in twelve pure solvents including n-propanol, isopropanol, n-butanol, isobutanol, isopentanol, isopropyl acetate, methyl tert-butyl ether, isopropyl ether, acetonitrile, n-octane, n-heptane and n-hexane over the temperatures range from 283.15 to 323.15 K under atmospheric pressure. The results indicated that the solubility of flurbiprofen increased with the increasing temperature. Furthermore, the experimental solubility data were correlated by the modified Apelblat equation, λh equation, Wilson model and NRTL model. And the modified Apelblat equation can give better correlation results with lower values of ARD%. Moreover, mixing and dissolution thermodynamic properties of flurbiprofen in different solvents were calculated according to the experimental data and the NRTL model.

By using the chemically dealloying method, three-dimensional nano-porous silver films (3-D NPSFs) are fabricated into a novel sensor for detecting hydrogen peroxide. The precursor films are prepared by high vacuum magnetron co-sputtering. High-resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) are taken to investigate the structure and the micro morphology of the precursor films and nano-porous films. We find that the precursor films are composed of glassy matrix and nanocrystallines. After dealloying, the films exhibit a combination of homogenously distributed pores and silver filaments, and exhibit an open, three dimensional bicontinuous interpenetrating ligament–channel structure. Thickness and morphology of the films can be easily controlled by the sputtering time and alloy composition of the precursor films, respectively. In addition, NPSFs show a good linear responding for the concentration of hydrogen peroxide in phosphate buffered solutions, which indicates NPSFs could be a promising electrochemical material for hydrogen peroxide detection.