This study describes the first application of an improved procedure on a pencil graphite electrode decorated with functionalized multi-walled carbon nanotubes (-MWCNTs/PGE) for the determination of the COVID-19 antiviral drug, favipiravir (FVP). The electrochemical behavior of FVP at f-MWCNTs/PGE was examined by cyclic voltammetry and differential pulse voltammetry (DPV) methods, and it was noted that the voltammetric response significantly increased with the modification of -MWCNTs to the surface. The linear range and limit of detection from DPV studies were determined as 1-1500 µM and 0.27 µM, respectively. In addition, the selectivity of the method was tested toward potential interferences, which can be present in pharmaceutical and biological samples, and it was found that -MWCNTs/PGE showed high selectivity for the determination of FVP in the presence of probable interferences. The results with high accuracies and precisions from the obtained feasibility studies also revealed that the designed procedure can be used for accurate and selective voltammetric determination of FVP in real samples.

Molecular docking simulation is a very popular and well-established computational approach and has been extensively used to understand molecular interactions between a natural organic molecule (ideally taken as a receptor) such as an enzyme, protein, DNA, RNA and a natural or synthetic organic/inorganic molecule (considered as a ligand). But the implementation of docking ideas to synthetic organic, inorganic, or hybrid systems is very limited with respect to their use as a receptor despite their huge popularity in different experimental systems. In this context, molecular docking can be an efficient computational tool for understanding the role of intermolecular interactions in hybrid systems that can help in designing materials on mesoscale for different applications. The current review focuses on the implementation of the docking method in organic, inorganic, and hybrid systems along with examples from different case studies. We describe different resources, including databases and tools required in the docking study and applications. The concept of docking techniques, types of docking models, and the role of different intermolecular interactions involved in the docking process to understand the binding mechanisms are explained. Finally, the challenges and limitations of dockings are also discussed in this review.

In this article, we introduce a new communication strategy called the "communication success dimension" for the suppression and eradication of chemophobia. We explain, using recent examples, that chemophobia presents a danger not only to the science of chemistry but also to humankind. Based on the latest insights from communication research, we emphasize the need to bring more passion, dedication, and human factors into the communication of chemistry. We demonstrate the application of this new strategy by employing Marcel Proust's to combat chemophobia.

Glycosylation is one of the most significant and abundant post-translational modifications in cells. Glycomic and glycoproteomic analyses involve the characterization of oligosaccharides (glycans) conjugated to proteins. Glycomic and glycoproteomic analysis is highly challenging because of the large diversity of structures, low abundance, site-specific heterogeneity, and poor ionization efficiency of glycans and glycopeptides in mass spectrometry (MS). MS is a key tool for characterization of glycans and glycopeptides. However, MS alone does not always provide full structural and quantitative information for many reasons, and thus MS is combined with some separation technique. This review focuses on the role of separation techniques used in glycomic and glycoproteomic analyses, liquid chromatography and capillary electrophoresis. The most important separation conditions and results are presented and discussed.

The synthesis and characterization of two Co(II) complexes stabilized by a tridentate SCS pincer ligand are described. Paramagnetic [Co(κ-SCS-Et)] and [Co(κ-SCS-Bu)(κ-SCS-Bu)] were obtained via transmetalation protocol from CoBr and S(C-Br)S-R (R = Et, Bu). Oxidation of the latter with [CpFe]PF affords the diamagnetic 18 VE complex [Co(κ-SCS-Bu)]PF. X-ray structures and DFT calculations are presented.

New Schiff bases functionalized with amide and phenolic groups synthesized by the condensation of 2-hydroxybenzaldehyde and 2-hydroxyacetophenone with amino acid amides which in turn were prepared in two steps from -Boc-amino acids and homoveraltrylamine through intermediate compounds -Boc-amino acids amides. The compounds were characterized by elemental analysis, FT-IR, UV-Vis, and NMR spectroscopy. The crystal structures of three Schiff bases were determined by single crystal X-ray diffraction. There exists O-H N, N-H O, and C-H O types of hydrogen bonds and C-H secondary bonding interactions in these crystalline solids. The Schiff bases have been screened for anticoagulant and antiplatelet aggregation activities. All the compounds showed procoagulant activity which shortens the clotting time of citrated human plasma in both platelet-rich plasma and platelet-poor plasma except the derivatives of L-methionine which showed anticoagulant activity by prolonging the clotting time. In addition, the compounds derived from benzyl cysteine and phenylalanine showed adenosine diphosphate induced antiplatelet aggregation activity, whereas others did not show any role. Moreover, all these compounds revealed non-hemolytic activity with red blood cells.

Herein, we present a new route to synthesize poly(2-oxazoline)s (POx) with coumarin moieties as pendant groups that can be crosslinked by irradiation to form hydrogels. The synthesis of a novel coumarin-containing 2-oxazoline monomer, 2-[(4-methyl-7-coumarinyloxy)methyl]oxazoline is described in four steps and further its subsequent homo- and copolymerization with 2-ethyl-2-oxazoline (EtOx) via cationic ring-opening polymerization (CROP). The received polymers with different coumarin content (8, 4 and 2 mol%) were compared with a known copolymer synthesized via postpolymerization modification of partially hydrolyzed poly(2-ethyl-2-oxazoline) (PEtOx) with a coumarin derivative. The thermoresponsive behavior of the POx in aqueous solutions was investigated, showing a clear difference in the cloud point temperature ( ) between the polymers synthesized via different strategies. The hydrogel formation was achieved by irradiation with UV light by the following two methods: on the one hand with the pure coumarin-containing POx and on the other hand mixed with poly(ethylene glycol) diacrylate (PEGDA). The obtained hydrogels were compared regarding their swelling degree and their gel content, whereas the swelling degree in water of prepared hydrogels can be tuned by using POx by varying the coumarin content.

Liposomes are nowadays a matter of tremendous interest. Due to their amphiphilic character, various substances with different properties can be incorporated into them and they are especially suitable as a model system for controlled transport of bioactive substances and drugs to the final destination in the body; for example, COVID-19 vaccines use liposomes as a carrier of mRNA. Liposomes mimicking composition of various biological membranes can be prepared with a proper choice of the lipids used, which proved to be important tool in the early drug development. This review deals with commonly used methods for the preparation and characterization of liposomes which is essential for their later use. The alternative capillary electrophoresis methods for physico-chemical characterization such as determination of membrane permeability of liposome, its size and charge, and encapsulation efficiency are included. Two different layouts using liposomes to yield more efficient separation of various analytes are also presented, capillary electrochromatography, and liposomal electrokinetic chromatography.

Several isotope-labeling strategies have been developed for the study of RNA by nuclear magnetic resonance (NMR) spectroscopy. Here, we report a combined chemical and enzymatic synthesis of [7-N]-guanosine-5'-triphosphates for incorporation into RNA via T7 RNA polymerase-based in vitro transcription. We showcase the utility of these labels to probe both structure and dynamics in two biologically important RNAs.

The synthesis, characterization, and reactivity of several group 4 metal complexes featuring a central anionic pyrrole moiety connected via CH linkers to two phosphine donors is described. Treatment of [P(NH)P-Pr] with [MCl(THF)] (M = Zr, Hf) in the presence of base yields the dimeric complexes [M(PNP)(μ-Cl)(Cl)] featuring two bridging chloride ligands. These complexes react with sodium cyclopentadienyl and SiMeI to give the mononuclear complexes [M(PNP)(η-Cp)(Cl)] and [M(PNP)(I)], respectively. The latter react with MeMgBr to form the trialkyl complexes [M(PNP)(Me)]. Upon treatment of [Ti(NMe)] with [P(NH)P-Pr] a complex with the general formula [Ti(PNP)(NMe)] is obtained. DFT calculations revealed that the most stable species is [Ti(κ- PNP)(NMe)] featuring a κ-bound PNP ligand. When [P(NH)P-Pr] is reacted with [Ti(NMe)] in CHCl complex [Ti(PNP)(Cl)(NMe)] is formed. Treatment of a solution of [P(NH)P-Pr] and [Zr(NMe)] with SiMeBr affords the anionic seven-coordinate tetrabromo complex [Zr(PNP)(Br)][HNMe]. The corresponding hafnium complex [Hf(PNP)(Br)][HNEt] is obtained in similar fashion by utilizing [Hf(NEt)] as metal precursor. All complexes are characterized by means of NMR spectroscopy. Representative complexes were also characterized by X-ray crystallography.

The spatial organization of metal oxide nanoparticles represents an important factor in the chemical utilization of resulting structures. For the production of networks that are composed of metal oxide nanoparticle chains, we dispersed vapor phase-grown TiO and ZnO nanoparticles homogeneously in an aqueous polyvinyl alcohol solution. After electrospinning, we analyzed the sizes and diameters of the compositionally homogeneous electrospun fibers and discussed the size distribution and morphology of the nanoparticles inside. Calcination-induced polymer removal gives rise to self-supported nanoparticle-based nanofibers. Particle coarsening by a factor of ~ 2 for TiO and ~ 3 for ZnO nanoparticles is observed.

Magnetoactive coordination compounds exhibiting bi- or multistability between two or more magnetic stable states present an attractive example of molecular switches. Currently, the research is focused on molecular nanomagnets, especially single molecule magnets (SMMs), which are molecules, where the slow relaxation of the magnetization based on the purely molecular origin is observed. Contrary to ferromagnets, the magnetic bistability of SMMs does not require intermolecular interactions, which makes them particularly interesting in terms of application potential, especially in the high-density storage of data. This paper aims to introduce the readers into a basic understanding of SMM behaviour, and furthermore, it provides an overview of the attractive Co(II) SMMs with emphasis on the relation between structural features, magnetic anisotropy, and slow relaxation of magnetization in tetra-, penta-, and hexacoordinate complexes.

Treatment of [Co(CO)] with the -substituted P(C-X)P ligands (X = Br, Cl; R = Pr, Bu) bearing Y = NH and CH linkers under solvothermal conditions affords the five-coordinate Co(I) and Co(III) complexes [Co(PCP-R)(CO)] and [Co(PCP-R)X]. The later are paramagnetic exhibiting a solution magnetic moment in the range of 3.0-3.3 μ which is consistent with a d intermediate spin system corresponding to two unpaired electrons. In the case of P(C-X)P ligands (X = Br, Cl; R = Bu; Y = NH) the formation of the square planar Co(II) complex [Co(PCP-Bu)X] was favored. This complex gives rise to a magnetic moment of 1.8 μ being consistent with a d low spin system corresponding to one unpaired electron. All complexes are characterized by means of spectroscopic techniques (NMR, IR), HR-MS. Representative complexes were also characterized by X-ray crystallography.

The synthesis, characterization, and reactivity of several new Cr(II) and Cr(III) complexes featuring an NCN pincer ligand with an arene backbone connected to amine donors NEt and NPr via CH-linkers is described. Reacting the in situ lithiated ligand precursor N(C-Br)N-Et with [CrCl(THF)] resulted in the formation of the Cr(III) complex -[Cr(κ-NCN-Et)(Cl)(THF)]. Upon reaction of lithiated N(C-Br)N-Pr with a suspension of anhydrous CrCl, the Cr(II) complex [Cr(κ-NCN-Pr)] is formed featuring two NCN ligands bound in κ-fashion. In contrast, when lithiated N(C-Br)N-Pr is reacted with a homogeneous solution of anhydrous Cr ( = Cl, Br), complexes [Cr(κNCN-Pr)X] are obtained. Treatment of [Cr(κNCN-Pr)Cl] with 1 equiv of PhCHMgCl and LiCHSiMe afforded the alkyl complexes [Cr(κ-NCN-Pr)(CHPh)] and [Cr(κ-NCN-Pr)(CHSiMe)]. All Cr(II) complexes exhibit effective magnetic moments in the range of 4.7-4.9  which is indicative for high spin systems. If a solution of lithiated N(C-Br)N-Pr is treated with CrCl, followed by addition of an excess of Na[HB(Et)], the dimeric complex [Cr(κ-NCN-Pr)(μ-H)] is obtained bearing two bridging hydride ligands. [Cr(κ-NCN-Pr)(CHSiMe)] turned out to be catalytically active for the hydrosilylation of ketones at room temperature with a catalyst loading of 1 mol%. X-ray structures of all complexes are presented.

Perylene monoimide based electron acceptors have great properties for use in organic solar cells, like thermal stability, strong absorption, and simple synthesis. However, they typically exhibit low values for the dielectric permittivity. This hinders efficient exciton dissociation, limiting the achievable power conversion efficiencies. In this work, we present the synthesis and utilization of two new acceptor-donor-acceptor (A-D-A) molecules, comprising perylene monoimide as electron withdrawing A unit. Oligo ethylene glycol side chain modified carbazole (PMI-[]) and fluorene (PMI-[]) linkers were used as electron rich D units, respectively. The polar side chains are expected to increase the polarizability of the molecules and, thus, their permittivity according to the Clausius-Mossotti relationship. We found that the incorporation of glycol chains improved the dielectric properties of both materials in comparison to the reference compounds with alkyl chains. The permittivity increased by 18% from 3.17 to 3.75 for the carbazole-based non-fullerene acceptor PMI-[] and by 12% from 3.10 to 3.47 for the fluorene-based acceptor PMI-[]. The fabricated solar cells revealed power conversion efficiencies of 3.71 ± 0.20% (record 3.92%) with PMI-[], and 1.21 ± 0.06% (record 1.51%) with PMI-[].

A series of substituted imidazoquinolines, a structurally related chemotype to pyrazoloquinolinones, a well-known class of GABA ligands, was prepared via two synthetic procedures and the efficiency of these procedures were compared. One method relies on classical heterocyclic synthesis, the other one aims at late-stage decoration of a truncated scaffold via direct C-H functionalization. A pharmacological evaluation disclosed that one of the synthesized derivatives showed interesting activity on a α1β3 containing receptor subtype.

The synthesis of novel pyrazolothienopyridinone derivatives as potential GABA receptor modulators was performed and is herein described. A crucial step of the synthesis involving handling unstable aminothiophenes was managed via two different synthetic strategies delivering a set of 8 target compounds.

Binding of 2-(5-mercapto-1,3,4-oxadiazol-2-yl)-6-methylquinolin-4-ol (C1), a biologically active substance, to bovine blood plasma albumin (BSA) at 293, 298, and 303 K was studied using fluorescence (steady state, synchronous, excitation/emission matrix) and FT-IR spectroscopy methods. The experimental results showed that C1 causes fluorescence quenching of BSA through both static and dynamic quenching mechanisms. The thermodynamic parameters, enthalpy and entropy change, for the static quenching were calculated to be - 35.73 kJ mol and - 35.34 J mol K, which indicated that hydrogen bonding and van der Waals interactions were the predominant intermolecular forces regulating C1-BSA interactions. Distance between donor and acceptor (2.14, 2.26, and 2.30 nm) depending on the temperature, obtained from intrinsic Förster resonance energy transfer calculations, revealed the static quenching mechanism of BSA fluorescence in 0-3.0 × 10 mol/dm concentration range of C1. The micro-environmental and conformational changes in BSA structure, established by synchronous, excitation/emission matrices and FT-IR spectra showed the changes in the BSA secondary structure.

The acid-base equilibria of six ACE inhibitors (ACEIs), captopril, cilazapril, enalapril, lisinopril, quinapril, and ramipril, were investigated in the presence of micelles of nonionic surfactant Brij 35. The p values were potentiometrically determined at 25 °C and at a constant ionic strength (0.1 M NaCl). The obtained potentiometric data were evaluated in the computer program Hyperquad. On the basis of the shift in the p values (Δp) determined in micellar media in relation to the p values previously determined in "pure" water, the effect of Brij 35 micelles on ACEIs ionization was estimated. The presence of nonionic Brij 35 micelles caused a shift in the p values of all ionizable groups of the investigated ACEIs (Δp from - 3.44 to + 1.9) while shifting the protolytic equilibria of both acidic and basic groups toward the molecular form. The Brij 35 micelles expressed the most pronounced effect on the ionization of captopril among the investigated ACEIs and stronger effect on the ionization of amino than on the ionization of carboxyl groups. The obtained results suggest that ionizable functional groups of ACEIs are involved in interactions with palisade layer of nonionic Brij 35 micelles, which potentially can be considered in physiological conditions. Distribution diagrams of the investigated ACEIs equilibrium forms as a function of pH indicate that the change in distribution is most strongly expressed in pH range 4-8, which includes biopharmaceutically important pH values.

The growing interest in 3-methylcytidine (mC) originates from the recent discoveries of mC modified tRNAs in humans as well as its intensively debated occurrence in mRNA. Moreover, mC formation can be catalyzed by RNA without the assistance of proteins as has been demonstrated for a naturally occurring riboswitch fold using the methylated form of its cognate ligand as cofactor. Additionally, new RNA sequencing methods have been developed to detect this modification in transcriptome-wide manner. For all these reasons, an increasing demand for synthetic mC containing oligoribonucleotides is emerging. Their chemical synthesis relies on RNA solid-phase synthesis using phosphoramidite building blocks. Here, we describe a facile synthetic path towards N-acetylated 2'--TBDMS- and 2'--TOM mC phosphoramidites to provide an optimal toolbox for solid-phase synthesis of mC containing RNA.

In recent years, sugar alcohols have gained significant attention as organic phase change materials (PCMs) for thermal energy storage due to their comparably high thermal storage densities up to 350 J/g. In a computational study, outstandingly high values of up to ~ 450-500 J/g have been postulated for specific higher-carbon sugar alcohols. These optimized structures feature an even number of carbon atoms in the backbone and a stereochemical configuration in which all hydroxyl groups are in an 1,3--relationship, as found in the natural hexitol d-mannitol. However, these -configured higher-carbon sugar alcohols have not been experimentally investigated as PCMs yet and described synthetic routes are elaborate multiple steps syntheses. Therefore, we aimed to synthesize sugar alcohols of the -series with a concise synthetic protocol based on the indium-mediated acyloxyallylation (IMA) of aldoses. En route the C2-epimers were easily accessible, namely -configured sugar alcohols, bearing one set of hydroxyl groups in a suboptimal 1,3--realtionship. The synthesized compounds were found to possess thermal properties consistent with the predicted values, and the "perfect" higher-carbon sugar alcohol with eight carbon atoms was found to have indeed an outstanding high latent heat of fusion of ~ 380 J/g with a melting point of 260 °C.