Search

This work was inspired by a previous report (Janjua et al. J. Phys. Chem. A 113, 3576–3587, 2009) in which the nonlinear-optical (NLO) response strikingly improved with an increase in the conjugation path. Herein, the effect of donor and acceptor substitutions on the geometrical parameters, electronic, optical and reactivity of argon in organic matrices has been computed by computational methods. The 6–311 ++ g(2d,2p) basis set and second order Moller–Plesset perturbation theory are used to explore mixed-argon benzonitrile compounds (1–7) namely; hydrogen argon cyanide, methyl argon cyanide, phenyl argon cyanide, cyano-phenyl argon cyanide, hydroxy-phenyl argon cyanide, nitro-phenyl argon cyanide and methoxy-phenyl argon cyanide respectively. Mullikan population analysis, natural bonding orbital (NBO) analysis, frontier molecular orbital analysis, molecular electrostatic potential surface analysis, polarizability and hyperpolarizability of noble gases in organic matrices have been studied. The results indicate that the electron donating groups (hydroxy, methoxy, phenyl and methyl) and electron withdrawing groups (nitro and cyano) fine tune the HOMO–LUMO orbitals and nonlinear optical properties. NBO analysis confirmed that these donor–acceptor groups support the charge transfer in our investigated jack-in-the-box compounds. The linear polarizability and first hyperpolarizability results suggest that all the studied compounds are good candidates for NLO response and associated applications.

Drinking water quality is considered to be of vital importance for all human beings and animals but its significance is much more heightened when consumer is a teenager. In view of foregone, groundwater quality assessment of 150 public schools situated in flooded areas of Southern Punjab, Pakistan, was carried out. Analysis results revealed that 49 and 37 % water samples are contaminated with coliform and faecal coliforms, respectively. On the other hand chemicals constituents in samples, including calcium (43 %), magnesium (11 %), potassium (37 %), sodium (31 %), sulphate (39 %), hardness (31 %), total dissolved solids (TDS) (35 %) and chloride (15 %) were higher than World Health Organization (WHO) limits. The situation is more serious as fluoride, iron and arsenic were also found in high concentration in 15, 60 and 58 % samples, respectively. Health risk assessment data indicated that mean chronic daily intake (CDI) values for children and adults were 0.592 and 0.537 μg/kg/day for arsenic and 0.012 and 0.011 μg/kg/day for iron, respectively. Calculated arsenic health risk index (HRI) > 1 for 88 and 58 % water samples for children and adults respectively, which highlights possible health risks associated with intake of contaminated water.

Synthesis of C-2 N-substituted anthranilamide derivatives was carried out in a straight forward manner, utilizing 2-aminobenzamide and benzyl chloride as starting materials. Their crystal structures have been established by single crystal X-ray crystallographic method. In the molecules of 2-benzylamino-benzamide (3a), intramolecular hydrogen bonding b/w O atom and proton of –NH and classical intermolecular hydrogen bonding of the type N–H · · · O forming eight membered rings in R4 2(8) pattern. In both molecules of 2-(dibenzylamino)benzamide (3b), unlike the molecule in 3a, each H atoms is pointed towards N atom causing intramolecular hydrogen bonding interactions, resulting in S(6) motifs. However, it is interesting to note that both molecules in 3b are lying about inversion centres and form dimers in R4 2(8) motifs; the two dimers are linked via non-classical intermolecular hydrogen bonds C–H · · · O resulting in clusters of four molecules in the structure. In vitro assay results revealed that molecule 3b with IC50 values of 3.8 ± 0.08 μM (AChE) and 17.6 ± 1.10 μM (BChE) possessed better cholinesterase (AChE and BChE) inhibition potential as compared to standard drug galantamine. Preliminary in silico studies showed that more biological active derivatives were also having good pharmacokinetic profile with no AMES toxicity and carcinogenicity.

Alzheimer’s disease (AD) causes dementia and continuous damage to brain cells. Cholinesterase inhibitors can alleviate the condition by increasing communication between the nerve cells and reducing the risk of dementia. In an effort to treat Alzheimer’s disease, we synthesized flurbiprofen-based diamines (1,2 diaminoethane and 1,3 diaminopropane) Zn(II), Cu(II) metal complexes and characterized them by single-crystal X-ray analysis, NMR, (FT)-IR, UV-Vis, magnetic susceptibility, elemental analysis and conductivities measurements. Synthesized diamine metal complexes appeared in ionic forms and have distorted octahedral geometry based on conductivity studies, magnetic susceptibility and electronic studies. Single crystal X-ray diffraction analysis confirmed (2b) Cu(H2O)2(L1)2(L2)2 complex formation. Moreover, we tested all synthesized metal complexes against the cholinesterase enzyme that showed higher inhibition potential. In general, copper metal complexes showed higher inhibitory activities than simple metal complexes with flurbiprofen. These synthesized metal complexes may derive more effective and safe inhibitors for cholinesterases.

Herbal industry of developing countries is facing several technical issues related to the extraction conditions in order to attain the maximum yield of a plant extract with maximum therapeutic attributes. Therefore the present study was aimed to investigate the best technique for respective herbal products. The effect of three different extraction techniques: ultrasonic assisted extraction, microwave assisted and orbital shaker assisted extraction, by using three solvents (80% methanol, ethanol, and ethyl acetate) on the antioxidant potential of Caralluma tuberculata stem (non-conventional vegetable) extracts were investigated. Folin-Ciocalteu method was applied on tested samples in order to find the concentration of total phenols. Therefore, the optimized extract of high yield and maximum total phenolic content was selected for further analysis like total flavonoid contents, FRAP, DPPH and ABTS scavenging potential. Quantification of phenolic acids in the extracts was also carried out by HPLC. Significant variation was observed in the yield of total phenols within the extracts, but better results were obtained in aqueous methanolic extract of ultrasonic assisted extraction, followed by microwave assisted and orbital shaker assisted extraction. Present findings supported the view that ultrasonic assisted extraction can be used for phytochemicals profiling, activity guided assays and the development of herbal products. Correlation coefficients of active principles indicated a significant relationship to antioxidant capacity P < 0.05.

In search of potent urease inhibitors, we have biologically evaluated our synthesized imine derivatives against jack bean urease. In vitro assay results showed that compound 3f with IC50 value of 16.50 ± 0.20 µM can be considered as the most potent urease inhibitor, whereas compounds 3a (IC50 = 23.10 ± 0.11 µM) and 3n (IC50 = 23.34 ± 0.21 µM) were second and third most potent inhibitors, respectively. In silico study revealed that all compounds have good penetration across BBB and HIA; however, AMES toxicity and carcinogenic profiles of more than half of the compounds were not satisfactory. Leading compound 3f was predicted to have very less penetration across BBB, whereas pharmacokinetic profile of compound 3l was better than all other compounds with no toxicity and carcinogenicity. The synthesized compounds can be used as structural foundation for the preparation of new potent urease inhibitors.

Pursuing the strategy of developing potent AChE inhibitors, we attempted to carry out the N1-substitution of 2,3-dihydroquinazolin-4(1H)-one core. A set of 32 N-alkylated/benzylated quinazoline derivatives were synthesized, characterized and evaluated for their inhibition against cholinesterases. N-alkylation of the series of the compounds reported previously (N-unsubstituted) resulted in improved activity. All the compounds showed inhibition of both enzymes in the micromolar to submicromolar range. Structure activity relationship (SAR) of the 32 derivatives showed that N-benzylated compounds possess good activity than N-alkylated compounds. N-benzylated compounds 2ad and 2af were found very active with their IC50 values toward AChE in submicromolar range (0.8 µM and 0.6 µM respectively). Binding modes of the synthesized compounds were explored by using GOLD (Genetic Optimization for Ligand Docking) suit v5.4.1. Computational predictions of ADMET studies reveal that all the compounds have good pharmacokinetic properties with no AMES toxicity and carcinogenicity. Moreover, all the compounds are predicted to be absorbed in human intestine and also have the ability to cross blood brain barrier. Overall, the synthesized compounds have established a structural foundation for the design of new inhibitors of cholinesterase.

Biodiesel is now-a-days recognized as a real potential alternative to petroleum-derived diesel fuel due to its number of desirable characteristics. However, its higher production cost resulting mainly due to use of costly food-grade vegetable oils as raw materials is the major barrier to its economic viability. Present work is an attempt to explore the potential of Eriobotrya japonica seed oil for the synthesis of biodiesel using alkali-catalyzed transesterification. Optimization of production parameters, namely molar ratio of alcohol to oil, amount of catalyst, reaction time and temperature, was carried out using Taguchi method. Fatty acid composition of both oil and biodiesel was determined using GC and H1 NMR. Alcohol to oil molar ratio of 6:1, catalyst amount of 1% wt/wt, 2 h reaction time and 50 °C reaction temperature were found to be the optimum conditions for obtaining 94.52% biodiesel. Highest % contribution was shown by the ‘amount of catalyst’ (67.32%) followed by molar ratio of alcohol...

In search of potent inhibitors of cholinesterases, we have synthesized and evaluate a number of 2,3-dihydroquinazolin-4(1H)-one derivatives. The synthetic approach provided an efficient synthesis of the target molecules with excellent yield. All the tested compounds showed activity against both the enzymes in micromolar range. In many case, the inhibition of both enzymes are higher than or comparable to the standard drug galatamine. With the selectivity index of 2.3 for AChE, compound 5f can be considered as a potential lead compound with a feature of dual AChE/BChE inhibition with IC50=1.6±0.10μM (AChE) and 3.7±0.18μM (BChE). Binding modes of the synthesized compounds were explored by using GOLD (Genetic Optimization for Ligand Docking) suit v5.4.1. The computed binding modes of these compounds in the active site of AChE and BChE provide an insight into the mechanism of inhibition of these two enzyme.

Purpose: To synthesize novel tris-diamine-derived transition metal complexes of flurbiprofen M(C2H8N2)3 (fp)2 and M(C3H10N2)3 (fp)2, and to evaluate their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities.Method: Tris-diamine-derived transition metal complexes of Co(II), Ni(II), and Mn(II) were synthesized and characterized using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform-infrared (FT-IR) spectroscopy, elemental analysis, magnetic susceptibility, conductivity measurement and single crystal x-ray analysis. The synthesized complexes were also evaluated for their AChE and BChE inhibitory activities.Results: Based on magnetic susceptibility and electronic studies, the synthesized complexes possessed distorted octahedral geometry. Conductance measurements indicated that diamine-derived metal complexes of flurbiprofen were electrolytes, whereas, simple metal complexes of flurbiprofen were non-electrolytes. The structure of Ni (C2H8N2)3 (fp)2 was also confirmed by single crystal x-ray analysis. The synthesized metal complexes exhibited moderate-to-very good inhibition of AChE and BChE. In vitro assays revealed that Ni complexes were most active, with the least half-maximal inhibitory concentration (IC50) values against AChE and BChE, compared to Co and Mn complexes. Furthermore, 1, 2-diaminoethane-derived complexes were more potent, with lower IC50 values against both AChE and BChE, compared to 1,3-diaminopropane-derived complexes. Among the complexes, 4a and 5a revealed significant cholinesterase inhibitory activities relative to the standard drug, galantamine.Conclusion: All the synthesized metal complexes are active against AChE and BChE, but only 4a and 5a are more active than the standard drug, galantamine, indicating their potential for drug development.Keywords: Flurbiprofen, Cholinesterase, Diamines, Galantamine, Metal complexes, Cholinesterase inhibition

Hair and nail samples from young Pakistani adults were separately analyzed for quantification of Cd, Cr, Cu, Ni, Pb, and Zn concentrations. The concentrations of these metals were also analyzed in commonly consumed local foods to evaluate potential correlation of hair and nail concentrations with diet. Pearson correlation coefficients ranged from 0.349 to 0.999, demonstrating diet to be a significant contributor for accumulation of heavy metals in humans.

The present study evaluated the influence of temperature, moisture, and microbial activity on the degradation and persistence of commonly used cotton pesticides, i.e., carbosulfan, carbofuran, lambda-cyhalothrin, endosulfan, and monocrotophos, with the help of laboratory incubation and lysimeter studies on sandy loam soil (Typic Ustocurepts) in Pakistan. Drainage from the lysimeters was sampled on days 49, 52, 59, 73, 100, 113, and 119 against the pesticide application on days 37, 63, 82, 108, and 137 after the sowing of cotton. Carbofuran, monocrotophos, and nitrate were detected in the drainage samples, with an average value, respectively, of 2.34, 2.6 microg/L, and 15.6 mg/L for no-tillage and 2.16, 2.3 microg/L, and 13.4 mg/L for tillage. In the laboratory, pesticide disappearance kinetics were measured with sterile and nonsterile soils from 0 to 10 cm in depth at 15, 25, and 35 degrees C and 50% and 90% field water capacities. Monocrotophos and carbosulfan dissipation followed first-order kinetics while others followed second-order kinetics. The results of incubation studies showed that temperature and moisture contents significantly reduced the t(1/2) (half-life) values of pesticides in sterile and nonsterile soil, but the effect of microbial activity was nearly significant that might be due to less organic carbon (0.3%). The presence of carbofuran and monocrotophos in the soil profile (0-10, 10-30, 30-60, 60-90, 90-150 cm) and the higher concentrations of endosulfan and lambda-cyhalothrin in the top layer (0-10 cm) showed the persistence of the pesticides. The detection of endosulfan and lambda-cyhalothrin in the 10-30 cm soil layer might be due to preferential flow. The data generated from this study could be helpful for risk assessment studies of pesticides and for validating pesticide transport models for sandy loam soils in cotton-growing areas of Pakistan.

This study was conducted to examine adsorption of pesticides bifenthrin, carbosulfan, λ-cyhalothrin, cypermethrin, endosulfan, parathion methyl, monocrotophos and 4-nitrophenol by sandy clay loam (S.C.L) and sandy loam (S.L) soils (with varying organic content). There was no significant difference between the observed soil water partitioning coefficient values (K d) derived from linear and nonlinear Freundlich isotherms. Adsorption of pesticides on S.C.L soils was higher than those on S.L soils. K d values showed significant correlations (r 2 = 0.8 − 0.99 and 0.65 − 0.97) with soil organic carbon content (OC) and weak correlations (r 2 = 0.2 − 0.29 and 0.1 − 0.18) with clay contents of S.C.L and S.L soil at p ≤ 0.05, respectively for all pesticides (except monocrotophos). Observed K oc values (soil-water partitioning constants based on the organic C fraction of the soil) were in accordance with the literature values of Wauchope and Tomlin with a maximum deviation of less than 0.5 log units. Ten Quantitati...

In Pakistan there is little data on environmental contamination of rural water sources by pesticides. This study evaluated pesticide contamination of groundwater in four intensive cotton growing districts. Water samples were collected from 37 rural open wells in the areas of Bahwalnagar, Muzafargarh, D.G. Khan and Rajan Pur districts of Punjab and analysed for eight pesticides which are mostly used. Information on types of pesticide used and distance to nearest pesticide mixing area and application areas was obtained for each site. From the eight pesticides analysed, six pesticides were detected in the water samples. Only cypermethrin and cabosulfan were not detected. The percentage of detection of bifenthrin, λ-cyhalothrin, carbofuran, endosulfan, methyl parathion and monocrotophos was, respectively 13.5%, 5.4%, 59.4%, 8%, 5.4% and 35.1% in July; 16.2%, 13.55%, 43.2%, 8%, N.D. (not detected) and 24.3% in October. Maximum contamination levels (MCLs) established by the U.S. Environmental Protection Agency for drinking water were not exceeded. The study has shown the need for monitoring pesticide contamination in rural water resources, and the development of drinking water quality standards for specific pesticides in Pakistan. The conclusions and recommendations will be disseminated to senior decision makers in central and local governments, extension agents and farmers. Keywords: Punjab Pakistan, Groundwater, Bifenthrin, Carbofuran, Cypermethrin, Endosulfan, λ-Cyhalothrin, Methyl parathion, Monocrotophos

The structures of N-(2-chloro­phenyl)-4-hydroxy-2-methyl-2H-1,2-benzo­thia­zine-3-carboxamide 1,1-dioxide and N-(4-chloro­phenyl)-4-hydroxy-2-methyl-2H-1,2-benzo­thia­zine-3-carboxamide 1,1-dioxide, both C16H13ClN2O4S, are stabilized by extensive intra­molecular hydrogen bonds. The 4-chloro derivative forms dimeric pairs of mol­ecules lying about inversion centres as a result of inter­molecular N—H⋯O hydrogen bonds, forming 14-membered rings representing an R22(14) motif; the 2-chloro derivative is devoid of any such inter­molecular hydrogen bonds. The heterocyclic thia­zine rings in both structures adopt half-chair conformations.

In the title compound, C15H14BrNO, the dihedral angle between the aromatic rings is 4.10 (11)° and the molecule is close to planar (r.m.s. deviation for the non-H atoms = 0.053 Å). An intramolecular O—H...N hydrogen bond closes an S(6) ring. In the crystal, very weak C—H...π interactions are observed.

In the title compound, C17H19NO2, the aromatic rings are oriented at a dihedral angle of 59.27 (12)°. In the crystal, inversion dimers linked by pairs of weak C—H...O interactions generate R22(12) loops.

The asymmetric unit of the title compound, C13H11ClN2, contains two geometrically distinct molecules; one molecule is close to planar [dihedral angle between the aromatic rings = 2.44 (18)°] and the other is twisted about the linking hydrazide group [dihedral angle = 14.08 (19)°]. In the crystal, the N—H groups do not form hydrogen bonds and the molecules are linked by weak C—H...π interactions.

In the title compound, C14H10FNO3, the dihedral angle between the two benzene rings is 32.66 (14)°. An S(6) ring motif is formed due to an intramolecular O—H...O hydrogen bond between the hydroxy and carbonyl groups. In the crystal, molecules are consolidated into dimers with R22(8) ring motifs by pairs of O—H...O hydrogen bonds.

In the title compound, C15H10Cl2N4O8, the methylacetate and dichloroanilinic groups are oriented at dihedral angles of 57.73 (8) and 62.44 (4)°, respectively to the dinitro-sustituted benzene ring. S(5) and S(7) rings are formed due to intramolecular N—H...Cl and N—H...O hydrogen bonds, respectively. In the crystal, N—H...O hydrogen bonds link the molecules into C(8) chains along the a axis. Further C—H...O and N—H...O hydrogen bonds link these chains in pairs, forming a polymeric network.

There are two independent molecules in the asymmetric unit of the title compound, C17H20N2, in which the dihedral angles between the aromatic rings are 30.34 (11) and 41.44 (8)°. In the crystal, weak C—H...π interactions may help to establish the packing.

In the title compound, C15H14N2O2, the 2,3-dimethylanilinic and benzaldehyde groups are planar, with r.m.s. deviations of 0.0101 and 0.0241 Å, respectively, and are oriented at a dihedral angle of 11.69 (3)°. The nitro group is inclined to the benzaldehyde group by 34.02 (9)°. The molecule adopts an E configuration about the C=N bond. In the crystal, molecules are linked via C—H...O interactions, giving rise to the formation of zigzag polymeric chains extending along [010]. They are also linked by C—H...π, and π–π interactions [centroid–centroid distance of 3.7185 (11) Å] involving symmetry-related aniline and benzene rings. The H atoms of the ortho-methyl group are disordered over two sites with a refined occupancy ratio of 0.69 (2):0.31 (2).

The asymmetric unit of the title compound, C13H11N3O2, contains two molecules with slightly different conformations: the dihedral angle between the aromatic rings is 13.01 (10)° in one molecule and 14.05 (10)° in the other. Both molecules feature short intramolecular C—H...O contacts, which generate S(6) rings. In the crystal, both molecules form inversion dimers linked by pairs of N—H...O hydrogen bonds, thereby generating R22(16) rings.

In the title compound, C15H14ClN, the conformation about the C=N bond is trans and the dihedral angle between the aromatic rings is 51.48 (4)°. In the crystal, some very weak C—H...π interactions may help to establish the packing.

In the title hydrated molecular salt, 2C7H8NO2+·SO42−·H2O, each cation in the asymmetric unit is stabilized by an intramolecular N—H...O hydrogen bond. The O atoms of the sulfate ion are disordered over two sets of sites with an occupancy ratio of 0.541 (13):0.459 (13), which possibly optimizes the acceptance of N—H...O hydrogen bonds from the cations. The crystal structure also features aromatic π–π stacking [centroid–centroid separation = 3.842 (2) Å] and a C—H...π interaction.

In the molecule of the title compound, 2C4H10N3O2+·SO4−, the cations are planar (r.m.s. deviations = 0.0144 and 0.0236 Å) and oriented at a dihedral angle of 62.30 (4)°. Intramolecular N—H...O hydrogen bonds result in the formation of two planar six-membered rings. The cations are linked to the sulfate ion through intermolecular C—H...O and N—H...O hydrogen bonds, forming an R22(8) ring motif. In the crystal structure, intermolecular N—H...O and C—H...O hydrogen bonds link the molecules into a three-dimensional network.

In the mol-ecule of the title compound, C(14)H(20)N(4)O(3), the five-membered ring adopts an envelope conformation with the O atom displaced by 0.207 (3) Å from the plane of the other ring atoms. Intra-molecular C-H⋯O hydrogen bonds result in the formation of three five-membered rings having envelope conformations. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules, forming R(2) (2)(20) ring motifs, which produce two-dimensional polymeric sheets extending along the b axis. There are also two C-H⋯π inter-actions. The H atoms of one of the methyl groups are disordered over two positions and were refined with occupancies of 0.50.

In the title molecule, C12H10Cl2, the torsion angles Cr—Cr—Cm—Cl around the Cm—Cr bonds have values of −104.1 (4) and −101.9 (4)°, where Cm is a methylene and Cr is a ring C atom. The molecules related by translation along the b axis are arranged into stacks by π–π interactions between unsubstituted and substituted aromatic rings of the naphthalene ring system (centroid–centroid distance = 3.940 Å).

The title compound, C10H10N2O2·H2O, is dimerized by inversion-related intermolecular N—H...O hydrogen bonding. There is an intramolecular N—H...O bond, resulting in a six-membered ring. Each dimer interacts with other dimers through hydrogen bonding with water molecules. The water molecules are linked to each other in a stair-like chain, thus generating two-dimensional polymeric strips. The dimers are also linked to each other through intermolecular C—H...O hydrogen bonding. There are π–π interactions between the aromatic and heterocyclic five-membered rings [centroid–centroid distance 3.8360 (12) Å]. C—H...π interactions also exist between CH2 groups and aromatic rings.

A series of group 12 elements for Zn(II), Cd(II), Hg(II) complexes of glibenclamide were synthesized and characterized using various spectroscopic techniques and magnetic moments. The complexes exhibited significant activity against gram-negative and gram-positive bacteria species. Zn(II) complex showed remarkable hypoglycemic activity whereas Cd(II) and Hg(II) complexes exhibited antibacterial activity.

Retraction of Acta Cryst. (2011), E67, m576–m577., The paper by Awan et al. [Acta Cryst. (2011 ▶), E67, m576–m577] is retracted. It has subsequently been shown that the crystal studied was an already known zinc compound, [Zn4Cl4(C2H6NS)4].

In the title molecule, C9H6Cl2N2S, the mean planes of the benzene and thiazole rings make a dihedral angle of 54.18 (8)°. In the crystal, molecules are joined into dimers with an R22(8) ring motif by pairs of N—H...N hydrogen bonds. These dimers are linked by C—H...Cl interactions into layers parallel to (011). The thiazole rings form columns along the c-axis direction, with a centroid–centroid separation of 3.8581 (9) Å, indicating π–π interactions. An intramolecular C—H...S contact also occurs.

In the title compound, C12H14N2S, the dihedral angle between the 1,3,5-trimethylbenzene and 1,3-thiazol-2-amine groups is 73.15 (4)°. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds generateR22(8) loops.

The paper by Awan et al. [Acta Cryst. (2011), E67, m576–m577] is retracted. It has subsequently been shown that the crystal studied was an already known zinc compound, [Zn4Cl4(C2H6NS)4].

There are two geometrically different molecules in the asymmetric unit of the title compound, C14H9Cl2NO3. The 5-amino-2-hydroxybenzoic acid units [r.m.s. deviations of 0.0323 and 0.0414 Å] and 2,6-dichlorobenzaldehyde groups [r.m.s. deviations of 0.0285 and 0.0226 Å] are roughly planar and oriented at dihedral angles of 11.69 (13) and 83.12 (6)° in the two molecules. An intramolecular O—H...O hydrogen bond completes an S(6) ring motif in each molecule. The two molecules form dimers with each other through intermolecular O—H...N and C—H...O hydrogen bonds, completing an R22(8) ring motif. The dimers are interlinked via intermolecular O—H...N and C—H...O hydrogen bonds, forming polymeric sheets.

In the title compound, C15H11NO4, the dihedral angle between the aromatic rings is 23.8 (2)° and an intramolecular O—H...N hydrogen bond generates an S(6) ring. In the crystal, C—H...O hydrogen bonds link the molecules into a three-dimensional network.

In the title compound, C14H11Cl2N, the dihedral angle between the 4-methylanilinic and 2,4-dichlorobenzaldehyde moieties is 7.37 (8)°. In the crystal, C—H...π interactions between the terminal methyl group and a symmetry-related ring of the anilinic group help to establish the packing.

In the title compound, C15H15NO, the almost planar 2,3-dimethylaniline unit and the salicylaldehyde group (r.m.s. deviations of 0.0156 and 0.0109 Å, respectively) are oriented at a dihedral angle of 43.69 (9)° with respect to each other. An S(6) ring motif is formed due to intramolecular O—H...N hydrogen bonding. In the crystal, C—H...π interactions occur between the 2,3-dimethylaniline unit and the salicylaldehyde group, where the CH is from the o-methyl group.

In the title compound, C16H13NO2, the 2,3-dimethylphenyl group and the 1H-isoindole-1,3(2H)-dione group are essentially planar, with r.m.s. deviations of 0.006 and 0.013 Å, respectively, and are oriented at an angle of 78.19 (3)° with respect to each other. In the crystal, weak C—H...O interactions link the molecules, forming a zigzag chain parallel to the b axis. Futhermore, C—H...π interactions are present between the C—H group of isoindole and the 2,3-dimethylphenyl benzene ring. The H atoms of the ortho-methyl group are statistically disordered over two positions. Such disorder might be related to the antagonism between intramolecular steric repulsions and intermolecular C—H...O interactions.

The asymmetric unit of the title compound, C15H14ClNO2, contains two molecules with significantly different conformations: the dihedral angles between the 4-chloroaniline and 3,4-dimethoxyphenyl (excluding C atoms) moieties are 19.68 (7) and 45.54 (4)°. In the crystal, the molecules are linked by C—H...O hydrogen bonds and weak C—H...π interactions.

In the title compound, C13H14N2, the dihedral angle between the aromatic rings is 69.73 (14)°. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds generate R22(10) loops. A weak C—H...π interaction also occurs.

In the title compound, C14H14N2O, the dihedral angle between the aromatic rings is 9.30 (6)°. In the crystal, molecules are linked by C—H...π and N—H...π interactions.

In the title compound, C18H21NO3, the C=N bond has a trans conformation and the benzene rings are oriented at a dihedral angle of 61.32 (6)°. The C atoms of the three methoxy groups are all roughly coplanar with their attached ring [deviations = 0.219 (2), −0.097 (2) and −0.137 (2) Å]. In the crystal, a weak C—H...π interaction may help to establish the packing.

In the title compound, C22H19NO, the 2,3-dimethylanilinic group is planar with an r.m.s. deviation of 0.0226 Å. The phenyl rings with the carbonyl and imine substituents are also planar with r.m.s. deviations of 0.0019 and 0.0048 Å, respectively. These phenyl rings are oriented at dihedral angles of 74.70 (5) and 79.43 (5)°, respectively, with the 2,3-dimethylanilinic group, whereas the dihedral angle between them is 88.28 (4)°. Weak intramolecular C—H...N hydrogen bonding occurs and completes an S(5) ring motif in the molecule. In the crystal, weak π–π interactions are present between the carbonyl-containing phenyl rings at a centroid–centroid distance of 3.5958 (12) Å. C—H...π interactions between the 2,3-dimethylanilinic and the carbonyl-containing phenyl rings are also present, where the C—H group is from the former.

In the title compound, C15H14N2O2, the aromatic rings are oriented at a dihedral angle of 24.52 (5)°. The dihedral angle between the nitro group and its parent benzene ring is 9.22 (16)°. In the crystal, molecules interact through aromatic π—π stacking interactions [centroid–centroid separations = 3.8158 (14) and 3.9139 (14) Å].

In the centrosymmetric title compound, [Ag(4)(C(10)H(2)O(8))](n), the benzene ring has irregular bond lengths but remains planar (r.m.s. deviation 0.0002 Å). The Ag-O bond lengths are in the range 2.153 (3)-2.615 (4) Å. The carboxyl-ate groups are oriented at dihedral angles of 26.4 (5) and 74.9 (4)° to the benzene ring. The coordination behaviour of each carboxyl-ate O atom is different: in one carboxylate, the O atoms are coordinated to a single and two Ag atoms; in the other carboxylate, the O atoms are coordinated to two and three Ag atoms. Non-classical inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure. The title compound forms a three-dimensional polymeric network due to the coordination of the Ag atoms.

The title compound, C(12)H(19)O(4)P, has a distorted tetra-hedral geometry around the P atom. The molecules form dimers with R(2) (2)(10) ring motifs due to inter-molecular O-H⋯O hydrogen bonds. The double-bonded O atom of the phospho-nate group behaves as an acceptor and the hydr-oxy group acts as a donor. Both of the ethyl groups are disordered with occupancies of 0.55:0.45 and 0.725:0.275.

The title compound, C(10)H(12)N(3)O(+)·Cl(-), is a derivative of o-phthaldehyde and methyl-thio-urea. The mol-ecules form dimers through intra- and inter-molecular N-H⋯O hydrogen bonds. The dimers are further linked into chains through one C-H⋯Cl and two N-H⋯Cl hydrogen bonds.