Layered double hydroxide – montmorillonite – a new nano‐dimensional material

A new nano‐dimensional material, layered double hydroxide – montmorillonite (LDH‐MMT), has been synthesized by the formation of an LDH in the presence of MMT. The structure is studied using X‐ray diffraction, Fourier transform infrared, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy analysis. The LDH‐MMT shows a novel layered structure containing negatively charged MMT layers and positively charged LDH layers with some sodium ions required to balance the charge. LDH‐MMT can be ion‐exchanged to obtain organically modified LDH‐MMT, and this material can be well‐dispersed in polystyrene. Copyright © 2012 John Wiley & Sons, Ltd.     

Structure of delphoside — A new isocoumarin glycoside

Summary A spectrophotometric method for determining cymarin and k-strophanthin- in the epigeal part ofAdonis chrysocyathus has been developed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 747–749, November–December, 1972.     

Synthesis,Crystal Structure,and Ultraviolet–Visible Spectrum of 8–Substituted–10,10–Dimethyl–10H–pyrido[1,2–a]indolium Perchlorates–Containing Thienyl Moiety

Two novel compounds, 8–[2–(2–thienyl)vinyl]–10,10–dimethyl–10H–pyrido[1,2–a] indolium perchlorate ( 3a ) and 8–[2–(5–phenyl–2–thienyl)vinyl]–10,10–dimethyl–10H–pyrido[1,2–a]indolium perchlorate ( 3b ) were synthesized and characterized by IR, ¹H–NMR, elemental analyses, and X–ray diffraction. Crystal structural analysis suggested that either 3a or 3b exhibited good coplanarity and rings and vinyl in the target molecule could make up a large conjugated system. Ultraviolet–visible absorption analysis indicated both 3a and 3b possessed large maximum absorptions, and 3b underwent a significant redshift (43.0 nm) in comparison with 3a .     

Hydrogen bonding and π–π stacking in 6‐hydroxy­biochanin A monohydrate

In the lattice of the title compound (systematic name: 5,6,7‐trihydroxy‐4′‐meth­oxy­isoflavone monohydrate), C₁₆H₁₂O₆·H₂O, the isoflavone mol­ecules are linked into chains through R₄³(17) motifs composed via O—H⋯O and C—H⋯O hydrogen bonds. Centrosymmetric R₄²(14) motifs assemble the chains into sheets. Hydrogen‐bonding and aromatic π–π stacking inter­actions lead to the formation of a three‐dimensional network structure.     

Two new polymorphs of 2,6‐diaminopyrimidin‐4(3H)‐one monohydrate

The title compound, C₄H₆N₄O·H₂O, crystallized simultaneously as a triclinic and a monoclinic polymorph from an aqueous solution of 2,4‐diaminopyrimidin‐6‐ol. Previously, an orthorhombic polymorph was isolated under the same experimental conditions. The molecular geometric parameters in the two present polymorphs and the previously reported orthorhombic polymorph are similar, but the structures differ in the details of their crystal packing. In the triclinic system, the diaminopyrimidinone molecules are connected to one another via N—H...O and N—H...N hydrogen bonding to form infinite chains in the [011] direction. The chains are further hydrogen bonded to the water molecules, resulting in a three‐dimensional network. In the monoclinic system, the diaminopyrimidinone molecules are hydrogen bonded together into two‐dimensional networks parallel to the bc plane. The water molecules link the planes to form a three‐dimensional polymeric structure.     

A new steroidal glycoside and a new phenyl glycoside from a ripe cherry tomato

A new steroidal glycoside and a new phenyl glycoside have been isolated from a ripe cherry tomato [Lycopersicon esculentum var. cerasiforme (DUNAL) ALEF., Solanaceae] along with two known steroidal alkaloid glycosides, esculeoisides A and B, and five aromatic compounds, zizibeoside I, benzyl alcohol beta-gentiobioside, rutin, methyl caffeate, and phenylalanine. Their chemical structures were determined on the basis of spectroscopic data as well as chemical evidence.     

2,5‐Dicarboxy­anilinium chloride monohydrate

The title compound, C₈H₈NO₄⁺·Cl⁻·H₂O, is the chloro­hydrated form of 2‐amino­benzene‐1,4‐dicarboxylic acid, the basic crystal structure of which is still not known. Mol­ecules are linked by classical N—H⋯O, O—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds, mainly along the mol­ecular plane, into sheets built by unusual R₆⁴(26), R₆⁴(22) and R₄³(22) rings. The stacking between layers is stabilized by another N—H⋯Cl hydrogen bond and by π–π inter­actions between aromatic rings facing each other.