Quantification of the Quercetin Nanoemulsion Technique Using Various Parameters.

Natural antioxidant polyphenolic compounds obtained from different plants are considered antioxidants for curing various chronic pathological diseases such as cardiovascular disorders and cancer. Quercetin (a polyphenolic flavonol) has attracted much attention from dietitians and medicinal chemists due to its wide variety of pharmacological activities, including anti-diabetic, anti-hypertensive, anti-carcinogenic, anti-asthmatic, anti-viral, and antioxidant activities. Furthermore, structurally, it is well suited to stabilize emulsions. The present review depicts the important role of the quercetin nanoemulsion technique, used to enhance the solubility of target materials both in vivo and in vitro as well as to decrease the risk of degradation and metabolism of drugs. Researchers have used cryo-TEM to study the morphology of quercetin nanoemulsions. The effects of various parameters such as pH, salts, and solvent concentration on quercetin nanoemulsion have been investigated for quercetin nanoemulsion. Many studies have used UV-Vis spectroscopy and HPLC for the characterization of these particles such as solubility, stability, and encapsulating efficiency.

Dimension and Flexibility of Polystyrenesulfonate Chains in Methanol-Water.

The influence of the relative permittivity of the solvent medium on the single-chain dimension and flexibility of sodium polystyrenesulfonate chains has been investigated in mixed solvent media of methanol and water using viscosity experiments. Particular attention has been paid to explore the effect of the added low-molar-mass electrolyte. The root-mean-square (rms) radii of gyration of the chains in the unperturbed state have been calculated by applying the Flory model, while the intrinsic persistence lengths by the Benoit-Doty equation on the basis of the Kratky-Porod worm-like chain model. Estimation of the expansion factors for the rms radius of gyration, and the electrostatic persistence length helps evaluate the rms radii of gyration and the total persistence length of polystyrenesulfonate chains in the presence of varying amount of the supporting electrolyte. The polyion chains are highly extended at low ionic strengths but exhibit coil-like behavior with small persistence lengths when an excess of the supporting electrolyte is added in all the methanol-water mixtures investigated. Specifically, in the investigated solvent media, the polystyrenesulfonate chains have been found to shrink by ∼63-65% in the θ-state from their expanded conformation in the presence of 0.0001 mol L-1 NaCl. The chain dimensions pass through a maximum as the medium becomes richer in methanol, which could be explained by the formation and breakup of internal rings involving the polyion chain and water and/or methanol molecules. The intrinsic persistence length of sodium polystyrenesulfonate in a methanol-water mixture containing 0.1 mole fraction of methanol is ca. 1.3 times that in a medium with 0.3 mole fraction of methanol, indicating that flexibility of the polyion depends appreciably on the relative permittivity of the medium.

Crystal structure and Hirshfeld surface analysis of (E)-2-[2-(2-amino-1-cyano-2-oxo-ethyl-idene)hydrazin-1-yl]benzoic acid N,N-di-methylformamide monosolvate.

In the title compound, C10H8N4O3·C3H7NO, the asymmetric unit contains two crystallographically independent mol-ecules A and B, each of which has one DMF solvate mol-ecule. Mol-ecules A and B both feature intra-molecular N-H⋯O hydrogen bonds, forming S(6) ring motifs and consolidating the mol-ecular configuration. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds connect mol-ecules A and B, forming R 2 2(8) ring motifs. Weak C-H⋯O inter-actions link the mol-ecules, forming layers parallel to the (12) plane. The DMF solvent mol-ecules are also connected to the main mol-ecules (A and B) by N-H⋯O hydrogen bonds. π-π stacking inter-actions [centroid-to-centroid distance = 3.8702 (17) Å] between the layers also increase the stability of the mol-ecular structure in the third dimension. According to the Hirshfeld surface study, O⋯H/H⋯O inter-actions are the most significant contributors to the crystal packing (27.5% for mol-ecule A and 25.1% for mol-ecule B).

Crystal structure of bis-[(η5-tert-butyl-cyclo-pentadien-yl)tri-carbonyl-molybdenum(I)](Mo-Mo).

The dinuclear mol-ecule of the title compound, [Mo2(C9H13)2(CO)6] or [Mo( t BuCp)(CO)3]2 where t Bu and Cp are tert-butyl and cyclo-penta-dienyl, is centrosymmetric and is characterized by an Mo-Mo bond length of 3.2323 (3) Å. Imposed by inversion symmetry, the t BuCp and the carbonyl ligands are in a transoid arrangement to each other. In the crystal, inter-molecular C-H⋯O contacts lead to the formation of layers parallel to the bc plane.

Syntheses, characterizations, crystal structures and Hirshfeld surface analyses of methyl 4-[4-(di-fluorometh-oxy)phen-yl]-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate, isopropyl 4-[4-(di-fluoro-meth-oxy)phen-yl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate and tert-butyl 4-[4-(di-fluoro-meth-oxy)phen-yl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate.

The crystal structures and Hirshfeld surface analyses of three similar compounds are reported. Methyl 4-[4-(di-fluoro-meth-oxy)phen-yl]-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate, (C21H23F2NO4), (I), crystallizes in the monoclinic space group C2/c with Z = 8, while isopropyl 4-[4-(di-fluoro-meth-oxy)phen-yl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carb-oxyl-ate, (C23H27F2NO4), (II) and tert-butyl 4-[4-(di-fluoro-meth-oxy)phen-yl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate, (C24H29F2NO4), (III) crystallize in the ortho-rhom-bic space group Pbca with Z = 8. In the crystal structure of (I), mol-ecules are linked by N-H⋯O and C-H⋯O inter-actions, forming a tri-periodic network, while mol-ecules of (II) and (III) are linked by N-H⋯O, C-H⋯F and C-H⋯π inter-actions, forming layers parallel to (002). The cohesion of the mol-ecular packing is ensured by van der Waals forces between these layers. In (I), the atoms of the 4-di-fluoro-meth-oxy-phenyl group are disordered over two sets of sites in a 0.647 (3): 0.353 (3) ratio. In (III), the atoms of the dimethyl group attached to the cyclo-hexane ring, and the two carbon atoms of the cyclo-hexane ring are disordered over two sets of sites in a 0.646 (3):0.354 (3) ratio.

Crystal structure and Hirshfeld surface analysis of dimethyl 4-hy-droxy-5,4'-dimethyl-2'-(toluene-4-sulfonyl-amino)-biphenyl-2,3-di-carboxyl-ate.

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

Crystal structure and Hirshfeld surface analysis of 3,3'-[ethane-1,2-diylbis(-oxy)]bis-(5,5-di-methyl-cyclo-hex-2-en-1-one) including an unknown solvate.

The title mol-ecule, C18H26O4, consists of two symmetrical halves related by the inversion centre at the mid-point of the central -C-C- bond. The hexene ring adopts an envelope conformation. In the crystal, the mol-ecules are connected into dimers by C-H⋯O hydrogen bonds with R 2 2(8) ring motifs, forming zigzag ribbons along the b-axis direction. According to a Hirshfeld surface analysis, H⋯H (68.2%) and O⋯H/H⋯O (25.9%) inter-actions are the most significant contributors to the crystal packing. The contribution of some disordered solvent to the scattering was removed using the SQUEEZE routine [Spek (2015 ▸). Acta Cryst. C71, 9-18] in PLATON. The solvent contribution was not included in the reported mol-ecular weight and density.

Crystal structure and Hirshfeld surface analysis of 1-[6-bromo-2-(4-fluoro-phen-yl)-1,2,3,4-tetra-hydroquinolin-4-yl]pyrrolidin-2-one.

In the title compound, C19H18BrFN2O, the pyrrolidine ring adopts an envelope conformation. In the crystal, mol-ecules are linked by inter-molecular N-H⋯O, C-H⋯O, C-H⋯F and C-H⋯Br hydrogen bonds, forming a three-dimensional network. In addition, C-H⋯π inter-actions connect mol-ecules into ribbons along the b-axis direction, consolidating the mol-ecular packing. The inter-molecular inter-actions in the crystal structure were qu-anti-fied and analysed using Hirshfeld surface analysis.

Synthesis, mol-ecular and crystal structure of [(NH2)2CSSC(NH2)2]2[RuBr6]Br2·3H2O.

The title compound, bis-[di-thio-bis-(formamidinium)] hexa-bromido-ruthenium dibromide trihydrate, [(NH2)2CSSC(NH2)2]2[RuBr6]Br2·3H2O, crystallizes in the ortho-rhom-bic system, space group Cmcm, Z = 4. The [RuBr6]2- anionic complex has an octa-hedral structure. The Ru-Br distances fall in the range 2.4779 (4)-2.4890 (4) Å. The S-S and C-S distances are 2.0282 (12) and 1.783 (2) Å, respectively. The H2O mol-ecules, Br- ions, and NH2 groups of the cation are linked by hydrogen bonds. The conformation of the cation is consolidated by intra-molecular O-H⋯Br, O-H⋯O, N-H⋯Br and N-H⋯O hydrogen bonds. The [(NH2)2CSSC(NH2)2]2+ cations form a hydrogen-bonded system involving the Br - ions and the water mol-ecules. Two Br - anions form four hydrogen bonds, each with the NH2 groups of two cations, thus linking the cations into a ring. The rings are connected by water mol-ecules, forming N-H⋯O-H⋯Br hydrogen bonds.

Crystal structure and Hirshfeld surface analysis of 4-(2-chloro-eth-yl)-5-methyl-1,2-di-hydro-pyrazol-3-one.

In the crystal of the title compound, C6H9ClN2O, mol-ecular pairs form dimers with an R 2 2(8) motif through N-H⋯O hydrogen bonds. These dimers are connect into ribbons parallel to the (100) plane with R 4 4(10) motifs by N-H⋯O hydrogen bonds along the c-axis direction. In addition, π-π [centroid-to-centroid distance = 3.4635 (9) Å] and C-Cl⋯π inter-actions between the ribbons form layers parallel to the (100) plane. The three-dimensional consolidation of the crystal structure is also ensured by Cl⋯H and Cl⋯Cl inter-actions between these layers. According to a Hirshfeld surface study, H⋯H (43.3%), Cl⋯H/H⋯Cl (22.1%) and O⋯H/H⋯O (18.7%) inter-actions are the most significant contributors to the crystal packing.

Crystal structure and Hirshfeld surface analysis of (2E)-1-phenyl-3-(1H-pyrrol-2-yl)propen-1-one.

The title com-pound, C13H11NO, adopts an E configuration about the C=C double bond. The pyrrole ring is inclined to the phenyl ring at an angle of 44.94 (8)°. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming ribbons parallel to (020) in zigzag C(7) chains along the a axis. These ribbons are connected via C-H⋯π inter-actions, forming a three-dimensional network. No significant π-π inter-actions are observed.

Crystal structures and Hirshfeld surface analyses of methyl 4-{2,2-di-chloro-1-[(E)-phenyl-diazen-yl]eth-enyl}benzoate, methyl 4-{2,2-di-chloro-1-[(E)-(4-methyl-phen-yl)diazen-yl]ethen-yl}benzoate and methyl 4-{2,2-di-chloro-1-[(E)-(3,4-di-methyl-phen-yl)diazen-yl]ethen-yl}benzoate.

The crystal structures and Hirshfeld surface analyses of three similar azo compounds are reported. Methyl 4-{2,2-di-chloro-1-[(E)-phenyl-diazen-yl]ethen-yl}benzoate, C16H12Cl2N2O2, (I), and methyl 4-{2,2-di-chloro-1-[(E)-(4-methyl-phen-yl)diazen-yl]ethen-yl}benzoate, C17H14Cl2N2O2, (II), crystallize in the space group P21/c with Z = 4, and methyl 4-{2,2-di-chloro-1-[(E)-(3,4-di-methyl-phen-yl)diazen-yl]ethen-yl}benzoate, C18H16Cl2N2O2, (III), in the space group P with Z = 2. In the crystal of (I), mol-ecules are linked by C-H⋯N hydrogen bonds, forming chains with C(6) motifs parallel to the b axis. Short inter-molecular Cl⋯O contacts of 2.8421 (16) Šand weak van der Waals inter-actions between these chains stabilize the crystal structure. In (II), mol-ecules are linked by C-H⋯O hydrogen bonds and C-Cl⋯π inter-actions, forming layers parallel to (010). Weak van der Waals inter-actions between these layers consolidate the mol-ecular packing. In (III), mol-ecules are linked by C-H⋯π and C-Cl⋯π inter-actions forming chains parallel to [011]. Furthermore, these chains are connected by C-Cl⋯π inter-actions parallel to the a axis, forming (01) layers. The stability of the mol-ecular packing is ensured by van der Waals forces between these layers.

Crystal structure and Hirshfeld surface analysis of 4-oxo-3-phenyl-2-sulfanyl-idene-5-(thio-phen-2-yl)-3,4,7,8,9,10-hexa-hydro-2H-pyrido[1,6-a:2,3-d']di-pyrimidine-6-carbo-nitrile.

In the title compound, C21H15N5OS2, mol-ecular pairs are linked by N-H⋯N hydrogen bonds along the c-axis direction and C-H⋯S and C-H⋯O hydrogen bonds along the b-axis direction, with R 2 2(12) and R 2 2(16) motifs, respectively, thus forming layers parallel to the (10) plane. In addition, C=S⋯π and C≡N⋯π inter-actions between the layers ensure crystal cohesion. The Hirshfeld surface analysis indicates that the major contributions to the crystal packing are H⋯H (43.0%), C⋯H/H⋯C (16.9%), N⋯H/H⋯N (11.3%) and S⋯H/H⋯S (10.9%) inter-actions.

Crystal structure and Hirshfeld surface analysis of dieth-yl (3aS,3a1R,4S,5S,6R,6aS,7R,9aS)-3a1,5,6,6a-tetra-hydro-1H,3H,4H,7H-3a,6:7,9a-di-epoxy-benzo[de]isochromene-4,5-di-carboxyl-ate.

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 tetra-hydro-furan and di-hydro-furan rings adopt envelope conformations. The oxane ring is puckered. The crystal structure features C-H⋯O hydrogen bonds, which link the mol-ecules into a three-dimensional network. According to a Hirshfeld surface study, H⋯H (60.3%) and O⋯H/H⋯O (35.3%) inter-actions 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 mol-ecules (A and B). In mol-ecule A, the central thio-phene 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 mol-ecule B, the corresponding dihedral angles are 89.49 (13), 54.64 (12)°, 83.62 (14)° and 85.67 (11)°, respectively. In the crystal, mol-ecular pairs are bonded to each other by N-H⋯N inter-actions. N-H⋯π and C-H⋯π inter-actions further connect the mol-ecules, forming a three-dimensional network. A Hirshfeld surface analysis indicates that H⋯H (57.1% for mol-ecule A; 57.3% for mol-ecule B), C⋯H/H⋯C (30.7% for mol-ecules A and B) and S⋯H/H⋯S (6.2% for mol-ecule A; 6.4% for mol-ecule B) inter-actions are the most important contributors to the crystal packing.

Crystal structure of [1,3-bis-(2,4,6-tri-methyl-phen-yl)imidazolidin-2-yl-idene]di-chlorido-(2-{[(2-methoxyeth-yl)(meth-yl)amino]-meth-yl}benzyl-idene)ruth-en-ium.

The title compound, [RuCl2(C33H43N3O)], is an example of a new generation of N,N-dialkyl ruthenium catalysts with an N-Ru coordination bond as part of a six-membered chelate ring. The Ru atom has an Addison τ parameter of 0.244, which indicates a geometry inter-mediate between square-based pyramidal and trigonal-bipyramidal. The complex shows the usual trans arrangement of the two chlorides, with Ru-Cl bond lengths of 2.3515 (8) and 2.379 (7) Å, and a Cl-Ru-Cl angle of 158.02 (3)°. One of the chlorine atoms and the atoms of the 2-meth-oxy-N-methyl-N-[(2-methyl-phen-yl)meth-yl]ethane-1-amine group of the title complex display disorder over two positions in a 0.889 (2): 0.111 (2) ratio.

Crystal structure and Hirshfeld surface analysis of 6-imino-8-(4-methyl-phen-yl)-1,3,4,6-tetra-hydro-2H-pyrido[1,2-a]pyrimidine-7,9-dicarbo-nitrile.

In the ten-membered 1,3,4,6-tetra-hydro-2H-pyrido[1,2-a]pyrimidine ring system of the title compound, C17H15N5, the 1,2-di-hydro-pyridine ring is essentially planar (r.m.s. deviation = 0.001 Å), while the 1,3-diazinane ring has a distorted twist-boat conformation. In the crystal, mol-ecules are linked by N-H⋯N and C-H⋯N hydrogen bonds, forming a three-dimensional network. In addition, C-H⋯π inter-actions form layers parallel to the (100) plane. Thus, crystal-structure cohesion is ensured. According to a Hirshfeld surface study, H⋯H (40.4%), N⋯H/H⋯N (28.6%) and C⋯H/H⋯C (24.1%) inter-actions are the most important contributors to the crystal packing.

Crystal structure and Hirshfeld surface analysis of 8-benzyl-1-[(4-methyl-phen-yl)sulfon-yl]-2,7,8,9-tetra-hydro-1H-3,6:10,13-diep-oxy-1,8-benzodi-aza-cyclo-penta-decine ethanol hemisolvate.

The asymmetric unit of the title compound, 2C31H28N2O4S·C2H6O, contains a parent mol-ecule and a half mol-ecule of ethanol solvent. The main compound stabilizes its mol-ecular conformation by forming a ring with an R 1 2(7) motif with the ethanol solvent mol-ecule. In the crystal, mol-ecules are connected by C-H⋯O and O-H⋯O hydrogen bonds, forming a three-dimensional network. In addition, C-H⋯π inter-actions also strengthen the mol-ecular packing.

Crystal structure and Hirshfeld surface analysis of (Z)-4-({[2-(benzo[b]thio-phen-3-yl)cyclo-pent-1-en-1-yl]meth-yl}(phen-yl)amino)-4-oxobut-2-enoic acid.

In the title compound, C24H21NO3S, the cyclopentene ring adopts an envelope conformation. In the crystal, mol-ecules are linked by C-H⋯π inter-actions, forming ribbons along the a axis. Inter-molecular C-H⋯O hydrogen bonds connect these ribbons to each other, forming layers parallel to the (01) plane. The mol-ecular packing is strengthened by van der Waals inter-actions between the layers. The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be H⋯H 46.0%, C⋯H/H⋯C 21.1%, O⋯H/H⋯O 20.6% and S⋯H/H⋯S 9.0%.

Crystal structure and Hirshfeld surface analysis of dimethyl 4'-bromo-3-oxo-5-(thio-phen-2-yl)-3,4,5,6-tetra-hydro-[1,1'-biphen-yl]-2,4-di-carboxyl-ate.

In the title compound, C20H17BrO5S, mol-ecules are connected by inter-molecular C-H⋯S hydrogen bonds with R 2 2(10) ring motifs, forming ribbons along the b-axis direction. C-H⋯π inter-actions consolidate the ribbon structure while van der Waals forces between the ribbons ensure the cohesion of the crystal structure. According to a Hirshfeld surface analysis, H⋯H (40.5%), O⋯H/H⋯O (27.0%), C⋯H/H⋯C (13.9%) and Br⋯H/H⋯Br (11.7%) inter-actions are the most significant contributors to the crystal packing. The thio-phene ring and its adjacent di-carboxyl-ate group and the three adjacent carbon atoms of the central hexene ring to which they are attached were refined as disordered over two sets of sites having occupancies of 0.8378 (15) and 0.1622 (15). The thio-phene group is disordered by a rotation of 180° around one bond.