Composite Based on Chitosan and Graphene Oxide

Graphene oxide (GO) and composites based on it are promising candidates for the implementation of the process of purification from polluting ions of heavy metals and organic compounds in waste and industrial waters. However, the limitations of the use of GO for water treatment are associated with the difficulties of its regeneration and extraction from aqueous solutions due to high hydrophobicity and dispersibility. We have synthesized graphene oxide by the modified Hammer method, which allows further functionalization. To improve the method of wastewater treatment, we obtained a new GO/chitosan nanocomposite by covalent and non-covalent grafting of chitosan to GO, so in the case of a covalent bond, we used thionyl chloride with further sonification of the mixture. Characterization and study of the morphology of the obtained graphene oxide by IR spectroscopy, X-ray diffraction and TEM analysis, which confirmed the possibility of the crosslinking reaction of GO and chitosan through the carbonyl and epoxy groups of GO located on the surface of the graphene oxide layer, which were obtained in large quantities due to the fact that we modified the method obtaining graphene oxide. The synthesized composites were tested as filters for cleaning the waters of the Caspian Sea, which is prone to oil pollution due to its proximity to the oil sector, and the amount of heavy metals is also increased in these waters

Extraction of the Composition of Olive Pits with Various Solvents

We have studied samples obtained from olive pits of different dimensions, determined the method for obtaining powder from olive pits, and also studied the best suitable time for collection. Crushed to a powder of powder and to particles of hard bones, they were placed in test tubes and filled with solvents. The solutions obtained by extraction with several solvents from the crushed powder of olive pits, collected in October 2021 in the Surakhani district of Baku, showed the best result. The resulting concentrates were studied and the optical density of the solutions was determined by UV spectroscopy; a method based on the Lambert–Bouguer–Beeroscopy law was applied

Crystal structure and Hirshfeld surface analysis of dimethyl (3aS,6R,6aS,7S)-2-(2,2,2-trifluoroacetyl)-2,3-dihydro-1H,6H,7H-3a,6:7,9a-diepoxybenzo[de]isoquinoline-3a1,6a-dicarboxylate

The title molecule, C18H16F3NO7, comprises a fused cyclic system containing four five-membered (two dihydrofuran and two tetrahydrofuran) rings and one six-membered (piperidine) ring. The five-membered dihydrofuran and tetrahydrofuran rings adopt envelope conformations, and the six-membered piperidine ring adopts a distorted chair conformation. Intramolecular O...F interactions help to stabilize the conformational arrangement. In the crystal structure, molecules are linked by weak C—H...O and C—H...F hydrogen bonds, forming a three-dimensional network. The Hirshfeld surface analysis confirms the dominant role of H...H contacts in establishing the packing

Crystal structure and Hirshfeld surface analysis of dimethyl 4-hydroxy-5,4′-dimethyl-2′-(toluene-4-sulfonylamino)biphenyl-2,3-dicarboxylate

In the title compound, C25H25NO7S, the molecular conformation is stabilized by intramolecular O—H...O and N—H...O hydrogen bonds, which form S(6) and S(8) ring motifs, respectively. The molecules are bent at the S atom with a C—SO2—NH—C torsion angle of −70.86 (11)°. In the crystal, molecules are linked by C—H...O and N—H...O hydrogen bonds, forming molecular layers parallel to the (100) plane. C—H...π interactions are observed between these layers

Crystal structure and Hirshfeld surface analysis of diethyl (3aS,3a1R,4S,5S,6R,6aS,7R,9aS)-3a1,5,6,6a-tetrahydro-1H,3H,4H,7H-3a,6:7,9a-diepoxybenzo[de]isochromene-4,5-dicarboxylate

In the title compound, C18H22O7, two hexane rings and an oxane ring are fused together. The two hexane rings tend toward a distorted boat conformation, while the tetrahydrofuran and dihydrofuran rings adopt envelope conformations. The oxane ring is puckered. The crystal structure features C—H...O hydrogen bonds, which link the molecules into a three-dimensional network. According to a Hirshfeld surface study, H...H (60.3%) and O...H/H...O (35.3%) interactions are the most significant contributors to the crystal packing

Crystal structure and Hirshfeld surface analysis of 3-benzyl-2-[bis(1H-pyrrol-2-yl)methyl]thiophene

In the title compound, C20H18N2S, the asymmetric unit comprises two similar molecules (A and B). In molecule A, the central thiophene ring makes dihedral angles of 89.96 (12) and 57.39 (13)° with the 1H-pyrrole rings, which are bent at 83.22 (14)° relative to each other, and makes an angle of 85.98 (11)° with the phenyl ring. In molecule B, the corresponding dihedral angles are 89.49 (13), 54.64 (12)°, 83.62 (14)° and 85.67 (11)°, respectively. In the crystal, molecular pairs are bonded to each other by N—H...N interactions. N—H...π and C—H...π interactions further connect the molecules, forming a three-dimensional network. A Hirshfeld surface analysis indicates that H...H (57.1% for molecule A; 57.3% for molecule B), C...H/H...C (30.7% for molecules A and B) and S...H/H...S (6.2% for molecule A; 6.4% for molecule B) interactions are the most important contributors to the crystal packing