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Parameters comprising the relative position and relative rotation of molecules can be evaluated when the principal axes of inertia of the entities in a supramolecular association are employed as reference. Such information applies to the characterization and identification of experimental and theoretical nonbonded systems. The parameters are relevant to geometric comparison (for theory and experiment) and, for instance, to monitoring structures by theoretical simulations. This work introduces a software developed to obtain such parameters through the discussion of some intriguing host-guest systems, the ferrocene/cucurbit[7]uril and ferrocenyl azide/β-cyclodextrin. The ideas within this contribution naturally apply to the study of other nonbonded associations beyond host-guest chemistry. A modified version of the software discussed herein serves to obtain user-defined spatial arrangements for two nonbonded entities. Therefore, with a given geometry, for instance, from X-ray data, the parameters can be derived, and with the parameters, from a theoretical perspective, a spatial arrangement can be obtained. Copyright © 2020 American Chemical Society.This work unveils the roles played by potato starch (ST) in the immobilization, photochemical reduction, and gas sensitivity of graphene oxide (GO) films. The ST/GO films are assembled layer by layer (LbL) onto quartz substrates by establishing mutual hydrogen bonds that drive a stepwise film growth, with equal amounts of materials being adsorbed in each deposition cycle. Afterward, the films are photochemically reduced with UV irradiation (254 nm), following a first-order kinetics that proceeds much faster when GO is assembled along with ST instead of a nonoxygenated polyelectrolyte, namely, poly(diallyl dimethylammonium) hydrochloride (PDAC). Finally, the gas-sensing performance of ST/reduced graphene oxide (RGO) and PDAC/RGO sensors fabricated via LbL atop of gold interdigitated microelectrodes is evaluated at different relative humidity levels and in different concentrations of ammonia, ethanol, and acetone. In comparison to the PDAC/RGO sensor, the ones containing ST are much more sensitive, especially when operating in a high-relative-humidity environment. An array comprising these chemical sensors provides unique electrical fingerprints for each of the investigated analytes and is capable of discriminating and quantifying them in a wide range of concentrations, from 10 to 1000 ppm. Copyright © 2020 American Chemical Society.Iron pentacarbonyl (Fe(CO)5) is a versatile material that is utilized as an inhibitor of flame, shows soot suppressibility, and is used as a precursor for focused electron-beam-induced deposition (FEBID). X-ray absorption near-edge structure (XANES) of the K edge, which is a powerful technique for monitoring the oxidation states and coordination environment of metal sites, can be used to gain insight into Fe(CO)5-related reaction mechanisms in in situ experiments. We use a finite difference method (FDM) and molecular-orbital-based time-dependent density functional theory (TDDFT) calculations to clarify the Fe K-edge XANES features of Fe(CO)5. The two pre-edge peaks P1 and P2 are mainly the Fe(1s) → Fe-C(σ*) and Fe(1s) → Fe-C(π*) transitions, respectively. When the geometry transformed from D 3h to C 4v symmetry, a ∼30% decrease of the pre-edge P2 intensity was observed in the simulated spectra. This implies that the π bonding of Fe and CO is sensitive to changes in geometry. The following rising edge and white line regions are assigned to the Fe(1s) → Fe(4p)(mixing C(2p)) transitions. Our results may provide useful information to interpret XANES spectra variations of in situ reactions of metal-CO or similar compounds with π acceptor ligandlike metal-CN complexes. Copyright © 2020 American Chemical Society.Environmentally benign mechanochemistry-assisted high-yielding synthesis of fluorescein-phenylalaninol (FPA) conjugates as a Schiff base receptor is reported herein. This newly synthesized fluorescent probe is found to be most exciting and efficient because of its simultaneous detection and removal of mercury ions (Hg2+) in aqueous medium and industrial effluents through precipitate formation. The receptor successfully worked as a chemosensor in selectively sensing the Hg2+ ion through the rapid transition from yellow to pink in the colorimetric as well as quenching of fluorescence intensity in the fluorometric assay. The removal of mercury ions was confirmed by the inductively coupled plasma analysis of the supernatant. The lower detection limit of Hg2+ ions for the receptor FPA is 1.65 and 0.34 μM as determined through absorption and fluorescence spectroscopic methods, respectively. The high removal efficiency (∼98%) of the mercury ions is promising and could be achieved via the formation of the complex in a 11 stoichiometric ratio of receptor to Hg2+ ions. Furthermore, this probe may be a practical alternative for use in a paper-based portable device for achieving on-site detection of mercury ions in solid, solution, and vapor phases. Copyright © 2020 American Chemical Society.A novel bimetallic and reusable Y2ZnO4 nanocatalyst was synthesized by a simple coprecipitation method. The prepared nanocatalyst exhibited dual catalytic activity and was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The average crystallite and grain sizes were found to be 17 ± 1 and 10 ± 2 nm, respectively. On the one hand, the catalytic activity of the nanocatalyst was studied for the Knoevenagel condensation reaction of aromatic aldehydes with active methylene compounds, such as ethyl cyanoacetate and malononitrile, under microwave irradiation and solvent-free conditions. On the other hand, the nanoparticles also showed faster photocatalytic activity against methyl orange (MO) compared to other dyes. The nanocatalyst was easily recoverable by a simple filtration method and was recycled without any significant loss of catalytic activity. The advantages of this nanocatalyst were a simple workup procedure, high reaction yields, solvent-free conditions, reusability, and a short reaction time under green reaction conditions. Copyright © 2020 American Chemical Society.Stimuli-responsive polymer architectures are attracting a lot of interest, but it still remains a great challenge to develop effective industrial-scale strategies. A single-stage and cost-effective approach was applied to fabricate a three-dimensional (3D) smart responsive surface with fast and reversibly switchable wetting between superhydrophobicity and superhydrophilicity/underwater superoleophobicity properties induced by photo and heat stimuli. Commercially available PVDF and P25TiO2 as starting materials fabricated with a scaled-up electrospinning approach were applied to prepare 3D smart switchable PVDF-P25TiO2 nanotextile superwetted by both UV and solar light that is simply recovered by heat at a reasonable time. The superhydrophilic/underwater superoleophobic photo-induced nanotextile will act in "water-removing" mode in which water quickly passes through and the oil is blocked on the surface. An acceptable recycling, reusing, and superior antifouling and self-cleaning performance arising from a TiO2 photocatalytic effect makes it highly desired in a green scaled-up industry oily wastewater treatment technology. With these advantages, a large-scale industrial production process can be simply simulated by applying a conducting mesh-like collector substrate. Copyright © 2020 American Chemical Society.Valproic acid (VP) is a very effective therapy for the management of generalized epilepsy. However, its use during pregnancy leads to increased risk of teratogenesis and cognitive malfunctioning in postnatal growing children. Antioxidants are used commercially as a palliative therapy. This study compares the different antioxidants effects on VP-induced teratogenicity. Pregnant female rats (n = 80) were divided into eight groups (n = 10) as follows Group I, control group; Group II, disease group valproic acid (500 mg/kg); Groups III and IV, treated with 2000 and 8000 mg/kg vitamin C, respectively; Groups V and VI, treated with selenium 100 and 200 μg/kg dose, respectively; and Groups VII and VIII, administered grape seed extract 300 and 600 mg/kg, respectively. Groups III-VIII received valproic acid (500 mg/kg) along with their respective treatments. All treatments were given via an oral route. The fetuses were double stained, and levels of superoxide dismutase (SOD), catalase (CAT), nitrite, glutathione (GSH), and malondialdehyde (MDA) were estimated. Resorption rate was significantly reduced in Vit. C treated groups at both dose levels. Maternal death rate was decreased remarkably in all treatment groups. Vit. C at a high dose (8000 mg/kg) and grape seed at a high dose (600 mg/kg) significantly reduced the incidence of delayed cervical ossification. The values of MDA were significantly reduced in all groups except the Vit. C group (2000 mg/kg). However, no significant elevation was observed in the values of SOD, CAT, and GSH. The current study concluded that vitamin C at a high dose (8000 mg/kg) and grape seed extract at a high dose (600 mg/kg) had partially protected the fetuses exposed to VP. Copyright © 2020 American Chemical Society.In this work, the self-assembly behavior of cetyltrimethylammonium bromide (CTAB) on the surface of citrate-capped gold nanoparticles (AuNPs) in solution has been studied by UV-vis absorption spectroscopy, fluorescence probe techniques, ζ potentiometric methods, transmission electron microscopy, etc. The UV-vis spectra show that the color with the increase of CTAB for the mixture containing CTAB and a given amount of AuNPs changes from red to blue and then to red. The absolute value of ζ potential corresponding to this color change decreases initially and then increases. Specially, the reversible color change, from red to blue and then to red, could be observed only in the case of a gradual addition of a AuNP solution to a CTAB solution; however, this reversible change is not suitable for the mixture formed in a reverse order of mixing. Tanespimycin clinical trial The results from pyrene used as the fluorescence probe indicate that the features in the fluorescence spectrum (including fluorescence quenching, I 1/I 3, and the excimer) well correspond to those from the UV-vis spectrum mentioned above. Based on the experimental results, the mechanism of the assembly structure variation of CTAB on the surface of negatively charged AuNPs was proposed. For a given amount of AuNPs, the assembly structure of CTAB on the surface of AuNPs undergoes the transformation from a monolayer to a bilayer with the increase of CTAB. In the case of the concentration of CTAB far beyond its critical micelle concentration (CMC) and the higher ratio of CTAB and AuNPs, there is a possibility of the formation of an extra micellar structure only after the formation of a double-layer structure. Copyright © 2020 American Chemical Society.Short histidine-rich peptides could serve as novel activatable vectors for delivering cytotoxic payloads to tumor and neovasculature cells. This explorative study reports preliminary results showing that zinc ions, which are found in elevated levels at neovasculature sites, can trigger the intracellular delivery of a short antimicrobial peptide when conjugated to a histidine-rich peptide through a disulfide bond. The importance of exofacial thiols in the mode of action of these disulfide-linked conjugates is also shown. Copyright © 2020 American Chemical Society.