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A series of five derivatives of the anticonvulsant drug phenytoin was synthesized, and their crystal structures were determined. The relationship between the molecular and crystal structure of the investigated compounds was rationalized in the context of contribution of intermolecular interactions and supramolecular structural motifs. The conformational preferences were analyzed by comparing the rotational freedom of the phenyl groups in the investigated compounds with 5,5-diphenylhydantoins from the Cambridge Structural Database. With the exception of compound 3bearing the cyclopropyl group, the crystal packing of the investigated compounds contains centrosymmetric dimers linked by paired N–H···O hydrogen bonds, which further self-organize through pairs of C–H···O interactions and a parallel interaction of two phenyl rings at a large offset into chains running along the c-axis. The principal feature of the crystal structure of compound 3is formation of the chains by N–H···O hydrogen bonds and C–H···O and C–H···π interactions. The coordination of phenytoin enables more rotational freedom for the phenyl groups. An emphasis was placed on docking of the investigated compounds into the voltage-gated ion channel in the open and closed state. The obtained results indicate that hydrogen bonding and hydrophobic interactions are dominant in stabilizing energetically favored orientations of the investigated compounds bound to the protein.

The preparation of epoxy/clay nanocomposites (NCs) and their insertion into coatings are of great importance since the NCs could enhance the protective performances. In this study, epoxy NCs with 1–10 wt% of nanoclay Cloisite 30B (C30B) were prepared by the sonication-assisted solution method. The rheological measurements of epoxy/C30B suspensions revealed non-Newtonian, shear-thinning behavior of the uncured NCs, with an increase in the viscosity, yield stress, and shear modules with increasing organoclay content, while the dispersion effectiveness of C30B decreased. A significant enhancement of the rheological parameters was observed at the second percolation threshold (4.1 vol%) due to the formation of a continuous network of 45-layer-thick tactoids. Although NCs with 1–3 wt% C30B exhibited slightly reduced mechanical and adhesion properties compared with the cured reference epoxy resin, the epoxy primer and topcoat based on NC with 1 wt% C30B generally displayed improved impact resistance and maintained flexibility, pendulum hardness, and good adhesion properties. Two-layer coating systems, i.e., NC-based primers and topcoats, had higher corrosion stability in a salt spray chamber compared to the unmodified system.

Transition-metal-oxide/transition-metal nanocomposites, such as NiO/Ni, FeO/Fe, and CoO/Co, have been the subject of much recent investigation (i) because of their potential applications and (ii) because they are good model systems for studies of some effects on the nanoscale. They are used, for example, as catalysts, fuel-cell electrodes, magnetic memories, etc. When a nanocomposite is composed of both ferromagnetic (FM) and antiferromagnetic (AFM) nanoparticles, interesting physical properties can occur, such as the phenomenon of exchange bias (EB). A Ni/NiO nanocomposite obtained by the thermal decomposition of nickel(II) acetate tetrahydrate, Ni(CH3COO)2·4H2O, at 300 °C is composed of NiO (62%) and Ni (38%) with crystallite sizes of 11 and 278 nm, respectively. We observed an increase in the crystallite size for NiO and decrease of crystallite size for Ni, a decrease in the microstrain for both and an increase in the NiO phase content with thermal annealing in air, while high-energy ball milling leads to a decrease of the crystallite size, an increase in the size of the agglomerates, and microstrain as well as reduction, NiO → Ni. The lattice parameters of the nanosized NiO and Ni show a deviation from the value for the bulk counterparts as a consequence of crystallite size reduction and the grain-surface relaxation effect. The exchange bias found in a milled sample with particles of 10 nm (NiO) and 11 nm (Ni) disappears for larger particles as a consequence of a coupling-area decrease between the antiferromagnetic and ferromagnetic particles. Due to reduction/oxidation (NiO ↔ Ni) and size as well as surface-relaxation effects the saturation magnetization value increases/decreases with milling/annealing, respectively. Having in mind the effect of size on the exchange bias, coercivity, and magnetization values, it is possible, by annealing/milling, to tailor the composition and particle size and then control the exchange bias and improve the other magnetic properties of the Ni/NiO.

Two binuclear complexes [Co2(C10H2O8)(C12H8N2)2(H2O)6]·2H2O (1) and [Ni2(C10H2O8)(C10H9N3)2(H2O)6]·4H2O (2) were synthesized and their structures were determined by X‐ray structure analysis. In both structures metal centres are in deformed octahedral environments and they are linked by bis‐monodentately coordinated 1,2,4,5‐benzenetetracarboxylate ligands as bridging units. In the packing arrangements of both compounds, binuclear units are connected by hydrogen bonds forming 2D pseudo‐layers, strengthened by face‐to‐face π‐πstacking interactions. The pseudo‐layers further construct 3D inorganic‐organic frameworks via system of hydrogen bonds. The complexes were also characterized by IR spectroscopy, TG and DSC analysis. Dehydration processes and thermal stability of the complexes are discussed. The dehydration enthalpies are calculated and the possible decomposition mechanisms are assumed.

The title complexes, catena‐poly[[aqua(1,10‐phenanthroline‐κ2N,N′)­cobalt(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ2O1:O4], [Co(C8H4O4)(C12H8N2)(H2O)], (I), and catena‐poly[[[(di‐2‐pyridyl‐κN‐amine)copper(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ4O1,O1′:O4,O4′] hydrate], [Cu(C8H4O4)(C10H9N3)]·H2O, (II), take the form of zigzag chains, with the 1,4‐benzene­di­carboxyl­ate ion acting as an amphimonodentate ligand in (I) and a bis‐bidentate ligand in (II). The CoIIion in (I) is five‐coordinate and has a distorted trigonal–bipyramidal geometry. The CuIIion in (II) is in a very distorted octahedral 4+2 environment, with the octahedron elongated along the transO—Cu—O bonds and with a transO—Cu—O angle of only 137.22 (8)°.