The hydrogen‐bonded adduct 7,16‐diazonia‐18‐crown‐6–4‐aminobenzenesulfonate–water (1/2/2)

In the title hydrated adduct, 1,4,10,13‐tetraoxa‐7,16‐diazo­nia­cyclo­octa­decane bis(4‐amino­benzene­sulfonate) dihydrate, C₁₂H₂₈N₂O₄²⁺·2C₆H₆NO₃S⁻·2H₂O, formed between 7,16‐di­aza‐18‐crown‐6 and the dihydrate of 4‐amino­benzene­sulfonic acid, the macrocyclic cations lie across centres of inversion in the orthorhombic space group Pbca. The anions alone form zigzag chains, and the cations and anions together form sheets that are linked via water mol­ecules and anions to form a three‐dimensional grid.     

The monoclinic polymorph of rac‐5,7,7,12,12,14‐hexa­methyl‐1,4,8,11‐tetraazonia­cyclo­tetra­decane bis­(hexa­fluoro­germanate) tetrahydrate

X‐ray data were obtained for the monoclinic polymorph of rac‐5,7,7,12,12,14‐hexa­methyl‐1,4,8,11‐tetraazonia­cyclo­tetra­decane bis­(hexa­fluoro­germanate) tetrahydrate, (C₁₆H₄₀N₄)[GeF₆]₂·4H₂O. The tetra­aza‐macrocyclic cations lie across inversion centers in space group P2₁/c. Water mol­ecules and [GeF₆]²⁻ anions form zigzag chains, which alternate in a three‐dimensional network with the macrocyclic cations. The structure is sustained by multiple hydrogen bonds.     

1‐(4‐Methyl­amino‐1,2,5‐thia­diazo­le‐3‐carbonyl)­thio­semicarbazide

In the title compound, C₅H₈N₆OS₂, the supramol­ecular architecture is sustained by two N—H...O and three N—H...S hydrogen bonds, and by N...S electrostatic interactions. The hydrogen‐bond network generates a sheet structure, which extends in the a and b directions and is one c‐cell dimension thick. These extended sheets are then linked across inversion centres in the c direction by N...S electrostatic interactions, thus forming a three‐dimensional network. The principal intermolecular dimensions include N(H)...O distances of 2.8393 (17) and 3.0268 (16) Å, N(H)...S distances in the range 3.2896 (14)–3.5924 (16) Å and N...S distances of 3.0822 (16) Å.     

Effect of Radiation from an Infrared Laser and <Emphasis Type="Italic">γ</Emphasis>-Rays from <Superscript>60</Superscript>Co on the Molecular–Topological Structure of Polyvinylidene Fluoride

We investigate the molecular–topological structure of polyvinylidene fluoride (PVDF) irradiated with γ-rays from ⁶⁰Co and IR radiation from a carbon dioxide laser by the thermomechanical spectroscopy method. The initial PVDF has a topological three-block network structure containing the low- and high-temperature amorphous blocks and crystalline fragments. Both types of irradiation can initiate interblock mass transfer of the macromolecular fragments from the amorphous to the crystalline form. As a result, unlike the predominantly amorphous structure of the native polymer, which is 7% crystalline, the weight fraction of the crystalline modification of the PVDF due to irradiation by an IR laser increases to 72%. Comparative analysis leads to the conclusion that the PVDF has a greater resistance to γ-irradiation than to IR laser irradiation. After IR laser irradiation, the pseudo-network structure of PVDF undergoes noticeable changes. The quantitative content of the crystalline fragments of macromolecules increases by almost an order of magnitude; the mobility of chains is reduced, and the rigidity of the chains is increased. However, the molecular flow of the polymer irradiated by the laser and γ-rays begins in the same temperature range (437 – 441 K) near where the native polymer is flowing (438 K).     

Proximity effect in the finite and incommensurate ferromagnet/superconductor systems

The original theory of a proximity effect is proposed for the bi- and tri-layered system ferromagnetic metal/superconductor (F/S) in dirty limit. The F₁/S/F₂ trilayer is examined more closely. The distinctions in materials, in thicknesses of F layers (d_f1 and d_f2), in parameters interfaces, and in local environments of layers are considered among the causes of incommensurability of trilayer. The peculiar T_c(d_f1, d_f2) interference pattern is predicted for the F₁/S/F₂ systems. The reentrant superconductivity and possibility of the better observability of the spin-valve regime are discussed.     

On a way to new types of the polyfunctional and polytopic systems based on cage metal complexes: Cadmium-promoted nucleophilic substitution with low-active nucleophilic agents

The nucleophilic substitution of the reactive halogen atoms of clathrochelate precursors with soft nucleophilic agents was promoted by cadmium(II) ion using various types of cadmium-containing compounds. Cadmium(II) activates the C–Hal bond both by the coordination of halogen substituents to this ion and the formation of anionic forms of a nucleophilic agent with cadmium amides, that increase the electron density on a reactive site of this agent. The cadmium-promoted substitution reactions of the reactive chlorine ribbed substituents in the di- and hexachlorine-containing clathrochelate precursors afforded the clathrochelate ribbed-functionalized derivatives of soft nucleophiles [alcohols (including fluorinated ones) and aromatic amines (including the nucleophiles with electron-withdrawing substituents)] by efficient one-pot procedures in high yields under mild conditions with generated in situ low-basic cadmium(II) alcoholates and amides. The complexes obtained were characterized using elemental analysis, MALDI-TOF mass spectrometry, IR, UV–Vis, ⁵⁷Fe Mössbauer, and NMR spectroscopies, and X-ray crystallography. The potential of cadmium-promoted reactions for synthesis of different types of organic and coordination compounds is discussed.