Supramolecular Cocrystals : Synthesis, Structural Characterizations And Theoretical Studies

In this research work, nineteen novel cocrystals of various carboxylic acids and bases have been investigated using spectroscopic methods such as powder and single crystal X-ray Crystallography, Infrared (FT-IR) and Nuclear Magnetic Resonance (NMR). The theoretical calculations of the cocrystals were performed using Density Functional Theory (DFT) method and Hirshfeld Surfaces analysis. Generally, the DFT and experimental results are comparable to each other except for the conformational difference around the carboxyl groups. Spectroscopic properties of the cocrystals were examined by FT-IR and NMR. Apart from the pKa values prediction, single crystal and powder X-ray diffractions show that all the samples are cocrystals

Water Washing Pretreatment On Empty Fruit Bunches Of Oil Palm Waste

The water washing pretreatment on empty fruit bunches (EFB) of oil palm waste has been investigated in this study, with the objective of removing some ash from the EFB to improve the quality of biomass. This study also investigated the effectiveness of water washing to remove ash by changing the appropriate parameters of the water washing pretreatment such as residence time, amount of water, type of water and use of soaking and stirring. Tap water and distilled water were solely used throughout the work

Crystal structure of 2,4-diamino-7-(hydroxymethyl)pteridin-1-ium nitrate

In the crystal of the title molecular salt, C7H9N6O+ NO3, the cations and anions are linked via N—HO and O—HO hydrogen bonds, forming sheets parallel to (100). Within the sheets there are numerous hydrogen-bonding ring motifs

2,6-Diamino-4-chloropyrimidinium 4-carboxybutanoate

In the title molecular salt, C4H6ClN4+.C5H7O4 -, the cation is essentially planar, with a maximum deviation of 0.037 (1) A ° for all non-H atoms. The anions are self-assembled through O—H...O hydrogen bonds, forming a supramolecular zigzag chain with graph-set notation C(8). In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H...O hydrogen bonds with an R2 2(8) ring motif. This motif further self-organizes through N—H...O and O—H...O hydrogen bonds, generating an array of six hydrogen bonds, the rings having graph-set notation R3 2(8), R2 2(8), R4 2(8), R2 2(8) and R3 2(8). In addition, another type of R2 2(8) motif is formed by inversion-related pyrimidinium cations via N—H...N hydrogen bonds, forming a two-dimensional network parallel to (101)

5-Amino-6-methylquinolin-1-ium hydrogen malonate–malonic acid (2/1)

The asymmetric unit of the title compound, 2C10H11N2+·2C3H3O4−·C3H4O4, consists of one 5-amino-6-methylquinolin-1-ium cation, one hydrogen malonate (2-carboxyacetate) anion and one-half molecule of malonic acid which lies on a twofold rotation axis. The quinoline ring system is essentially planar, with a maximum deviation of 0.062 (2) Å for all non-H atoms. In the anion, an intramolecular O—H...O hydrogen bond generates an S(6) ring. In the crystal, the components are linked via N—H...O and O—H...O hydrogen bonds into layers parallel to the ac plane. The crystal structure also features weak C—H...O hydrogen bonds and a π–π stacking interaction with a centroid–centroid distance of 3.8189 (10) Å

2-Amino-6-methylpyridinium 3-chlorobenzoate

In the title salt, C6H9N2+·C7H4ClO2−, the 3-chlorobenzoate anion shows a whole-molecule disorder over two positions with a refined occupancy ratio of 0.505 (4):0.495 (4). In the crystal, the cations and anions are linked via N—H...O hydrogen bonds, forming a centrosymmetric 2 + 2 aggregate with R22(8) and R42(8) ring motifs. The crystal structure also features a π–π stacking interaction between the pyridinium rings with a centroid–centroid distance of 3.8339 (9) Å

2-Amino-5-bromopyridinium 5-chloro-2-hydroxybenzoate

In the 5-chlorosalicylate anion of the title salt, C5H6BrN2+·C7H4ClO3−, an intramolecular O—H...O hydrogen bond with an S(6) graph-set motif is formed, so that the anion is essentially planar with a dihedral angle of 1.3 (5)° between the benzene ring and the carboxylate group. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms via a pair of N—H...O hydrogen bonds, forming an R22(8) ring motif. The crystal structure also features N—H...O and weak C—H...O interactions, resulting in a layer parallel to the (10-1) plane

8-Hydroxy-5,7-dimethylquinolin-1-ium chloride dihydrate

In the title hydrated salt, C11H12NO+·Cl−·2H2O, the quinoline ring system is essentially planar, with a maximum deviation of 0.005 (1) Å for all non-H atoms. In the crystal, the three components are linked by O—H...O, N—H...O, O—H...Cl and weak C—H...O hydrogen bonds, forming a layer structure parallel to the ac plane. The crystal structure is further stabilized by π–π stacking interactions, with centroid–centroid distances of 3.5213 (6) and 3.7176 (6) Å

5-Amino-6-methylquinolin-1-ium 3-carboxypropanoate

The asymmetric unit of the title salt, C10H11N2+·C4H5O4−, consists of two independent 5-amino-6-methylquinolin-1-ium cations and two 3-carboxypropanoate anions. Both cations are protonated at the pyridine N atoms and are essentially planar, with maximum deviations of 0.026 (3) and 0.016 (2) Å. In the crystal, the cations and anions are linked via N—H...O and O—H...O hydrogen bonds, forming a layer parallel to the ab plane. In the layer, weak C—H...O hydrogen bonds and π–π stacking interactions, with centroid-to-centroid distances of 3.7283 (15) and 3.8467 (15) Å, are observed. The crystal structure also features weak C—H...O hydrogen bonds between the layers

8-Hydroxy-5,7-dimethylquinolin-1-ium hydrogen sulfate

The quinoline ring system of the title salt, C11H12NO+·HSO4−, is essentially planar, with a maximum deviation of 0.054 (2) Å for all non H atoms. In the crystal, the cations and anions are linked via N—H...O, O—H...O and weak C—H...O hydrogen bonds, and are stacked respectively in columns along the a axis. π–π stacking interactions, with centroid–centroid distances of 3.5473 (12) and 3.6926 (12) Å, are also observed. The crystal studied was an inversion twin with refined components of 0.43 (7):0.57 (7)