An unusual conformation of gabapentin (Gpn) in Pyr‐Gpn‐NH‐NH‐Pyr stabilized by weak interactions

The crystal structure of N‐[(1‐{2‐oxo‐2‐[2‐(pyrazin‐2‐ylcarbonyl)hydrazin‐1‐yl]ethyl}cyclohexyl)methyl]pyrazine‐2‐carboxamide monohydrate (Pyr‐Gpn‐NN‐NH‐Pyr·H₂O), C₁₉H₂₃N₇O₃·H₂O, reveals an unusual trans–gauche (tg⁻) conformation for the gabapentin (Gpn) residue around the C^γ—C^β (θ₁) and C^β—C^α (θ₂) bonds. The molecular conformation is stabilized by intramolecular N—H...N hydrogen bonds and weak C—H...O interactions. The packing of the molecules in the crystal lattice shows a network of strong N—H...O and O—H...O hydrogen bonds together with weak C—H...O and π–π inteactions.     

Bioinspired Synthesis of Well‐Ordered Layered Organic–Inorganic Nanohybrids: Mimicking the Natural Processing of Nacre by Mineralization of Block Copolymer Templates

The unique mechanical performance of nacre, the pearly internal layer of shells, is highly dependent on its complex morphology. Inspired by the structure of nacre, the fabrication of well‐ordered layered inorganic–organic nanohybrids is presented herein. This biomimetic approach includes the use of a block copolymer template, consisting of hydrophobic poly(vinylidene fluoride) (PVDF) lamellae covered with hydrophilic poly(methacrylic acid) (PMAA), to direct silica (SiO₂) mineralization. The resulting PVDF/PMAA/SiO₂ nanohybrid material resembles biogenic nacre with respect to its well‐ordered and layered nanostructure, alternating organic–inorganic phases, macromolecular template, and mild processing conditions.

     

222Rn measurements in drinking water and annual effective dose for the adult population around a coal-based and atomic power plant in Uttar Pradesh,India

Journal of Radioanalytical and Nuclear Chemistry - Dissolved radon (222Rn) in drinking water has been measured using SMART RnDuo, a continuous radon monitor. Water samples have been collected from...     

A Facile Method for Detection and Speciation of Inorganic Selenium with Ion Chromatography

Chromatographia - In this work, we present a new method for the determination and speciation of selenium in water with ion chromatography (IC) using a conductometric detector. Chromatographic...     

Box–Behnken Design-Based Development and Validation of a Reverse-Phase HPLC Analytical Method for the Estimation of Paclitaxel in Cationic Liposomes

Chromatographia - Stability-indicating reverse-phase HPLC analytical method for the quantification of Paclitaxel (PTX) in the bulk and cationic liposomes was developed. The optimized method was...