Ion-selective and complexation properties, vibrational spectra, and crystal and molecular structure of 1,5-bis[2-(hydroxyethoxyphosphoryl)phenoxy]-3-oxapentane

The ion-selective properties of 1,5-bis[2-(hydroxyethoxyphosphoryl)phenoxy]-3-oxapentane H₂R² have been described. The molecular and crystal structure of H₂R² has been determined by powder X-ray crystallography and IR spectroscopy. The molecule has the twofold symmetry axis, orthorhombic crystal system, space group Pbcn, a = 16.830(2) ?, b = 8.866(15) ?, c = 15.7190(2) ?, V = 2346.1(6) ?³, Z = 4. A new CuR² · 2H₂O complex has been synthesized and characterized.     

Removal of organic substances and metal ions from water using a carbon-mineral sapropel sorbent

Physicochemical features relevant to sorption of organic substances and metal ions were examined for the synthesized carbon-mineral sapropel sorbent whose surface is composed of a combination of carbon and mineral segments.     

Stacking-Conformations in Functionally Substituted Phosphines

The methods of synthesis and space structure of phosphorus-containing compounds, in which stacking conformation is realized, are considered. It is shown that intramolecular stacking can be observed in monoheterocyclic compounds, bi-and polycyclic compounds, complexes of metals and acyclic compounds.     

Synthesis and gas sorption properties of halogen-doped mesoporous chromium(iii) terephthalate

Mesoporous chromium(iii) terephthalate MIL-101 was treated with aqueous solutions of sodium fluoride, chloride, and bromide. The properties of the resulting compounds to sorb nitrogen, hydrogen, and methane were studied. The methane sorption was shown to depend on the nature of the inserted halide ion. The treatment with a sodium chloride solution leads to an increase in the methane uptake by MIL-101.     

Alkyl-2,3-dibromo-3-nitroacrylates in the reactions with substituted hydrazines

The interaction of alkyl 2,3-dibromo-3-nitroacrylates with aroylhydrazines at room temperature or with 2,4-dinitrophenylhydrazine under reflux gives the corresponding 2-aroyl(aryl)hydrazono-3-bromo-3-nitropropanoates. Refluxing of ethyl 2,3-dibromo-3-nitroacrylate with a fourfold excess of benzoylhydrazine results in ethyl-2,3-bis(benzoylhydrazono)propanoate. The structure of compounds obtained has been proved by IR, ¹H NMR, ¹³C-{¹H} NMR, and electron spectroscopy methods.     

Synthesis of 5-Hydroxymethyl-8-methyl-3-(3-aryl-[1,2,4]oxadiazol-5-yl)-2H-pyrano[2,3-c]pyridin-2-ones and Their Esters

New 5-hydroxymethyl-8-methyl-3-(3-aryl-[1,2,4]oxadiazol-5-yl)-2H-pyrano-[2,3-c]pyridin-2-ones and their esters were synthesized. The structure of obtained compounds was determined through a complete ¹H NMR analysis.     

Alkylation of 3‐Phenyl‐1H‐pyrazolo[4,3‐c] quinoline: Theoretical Analysis of Regioselectivity

The interaction of 3‐phenyl‐1H‐pyrazolo[4.3‐c]quinoline with alkylating agents in the presence of NaH leads mainly to N1‐substituted derivatives. The regioselectivity of the reaction has been studied using AM1 semi‐empirical calculations in the isolated molecule approximation.     

Conformational polymorphs of 3‐cyclopropyl‐5‐(3‐methyl‐[1,2,4]triazolo[4,3‐a]pyridin‐7‐yl)‐1,2,4‐oxadiazole

The dipharmacophore compound 3‐cyclopropyl‐5‐(3‐methyl‐[1,2,4]triazolo[4,3‐a]pyridin‐7‐yl)‐1,2,4‐oxadiazole, C₁₂H₁₁N₅O, was studied on the assumption of its potential biological activity. Two polymorphic forms differ in both their molecular and crystal structures. The monoclinic polymorphic form was crystallized from more volatile solvents and contains a conformer with a higher relative energy. The basic molecule forms an abundance of interactions with relatively close energies. The orthorhombic polymorph was crystallized very slowly from isoamyl alcohol and contains a conformer with a much lower energy. The basic molecule forms two strong interactions and a large number of weak interactions. Stacking interactions of the `head‐to‐head' type in the monoclinic structure and of the `head‐to‐tail' type in the orthorhombic structure proved to be the strongest and form stacked columns in the two polymorphs. The main structural motif of the monoclinic structure is a double column where two stacked columns interact through weak C—H…N hydrogen bonds and dispersive interactions. In the orthorhombic structure, a single stacked column is the main structural motif. Periodic calculations confirmed that the orthorhombic structure obtained by slow evaporation has a lower lattice energy (0.97 kcal mol^?1) compared to the monoclinic structure.