A comprehensive study on the photophysical and non-linear optical properties of thienyl-chalcone derivatives.

The impact of the substitutional position of the chorine atom on the non-linear optical (NLO) response of chalcone derivatives is reported in this paper. Two thienyl-chalcone derivatives, (E)-3-(2,4-dichloro-phenyl)-1-(2,5-dichlorothiophen-3-yl)prop-2-en-1-one (3A25D2) and (E)-3-(2,6-dichloro-phenyl)-1-(2,5-dichlorothiophen-3-yl)prop-2-en-1-one (3A25D4), are synthesized, and their crystal structures were determined by single-crystal X-ray diffraction analysis. The photophysical and third-order NLO properties of 3A25D2 and 3A25D4 were investigated experimentally and computationally. The third-order NLO properties of 3A25D2 and 3A25D4 dissolved in N,N-dimethylformamide (DMF) were studied using Z-scan technique with 800 nm, 70 femtosecond (fs) pulses, and 532 nm continuous wave (CW) laser excitation. Closed aperture data recorded with fs pulses revealed positive non-linearity of both the compounds, while a strong negative non-linearity was observed in the CW regime. Open aperture data revealed that both the compounds exhibit positive non-linear absorption in fs pulsed and CW domains. Several wave function analysis methods, such as the inter-fragment charge transfer (IFCT) analysis, hole-electron analysis, (hyper)polarizability density analysis, and decomposition of the (hyper)polarizability contribution by numerical integration, were carried out to study the optical properties and charge transfer mechanism. In addition, the influence of the medium (liquid and crystalline) and external field wavelength on the optical properties of the two molecules were analyzed. Thermal and electronic contributions toward NLO properties were studied experimentally. The theoretically calculated cubic hyperpolarizability γ(-ω; ω, ω, -ω) in liquid for 3A25D2 and 3A25D4 were 4.69 × 10-34 and 2.68 × 10-34 esu, whereas the corresponding femtosecond regime Z-scan results gave 4.35 × 10-34 and 3.78 × 10-34 esu, respectively.

New 3-O-substituted xanthone derivatives as promising acetylcholinesterase inhibitors.

A new series of 3-O-substituted xanthone derivatives were synthesised and evaluated for their anti-cholinergic activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The results indicated that the xanthone derivatives possessed good AChE inhibitory activity with eleven of them (5, 8, 11, 17, 19, 21-23, 26-28) exhibited significant effects with the IC50 values ranged 0.88 to 1.28 µM. The AChE enzyme kinetic study of 3-(4-phenylbutoxy)-9H-xanthen-9-one (23) and ethyl 2-((9-oxo-9H-xanthen-3-yl)oxy)acetate (28) showed a mixed inhibition mechanism. Molecular docking study showed that 23 binds to the active site of AChE and interacts via extensive π-π stacking with the indole and phenol side chains of Trp86 and Tyr337, besides the hydrogen bonding with the hydration site and π-π interaction with the phenol side chain of Y72. This study revealed that 3-O-alkoxyl substituted xanthone derivatives are potential lead structures, especially 23 and 28 which can be further developed into potent AChE inhibitors.

Cholinesterase Inhibitory Activities of Adamantyl-Based Derivatives and Their Molecular Docking Studies.

Adamantyl-based compounds are clinically important for the treatments of type 2 diabetes and for their antiviral abilities, while many more are under development for other pharmaceutical uses. This study focused on the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of adamantyl-based ester derivatives with various substituents on the phenyl ring using Ellman's colorimetric method. Compound 2e with a 2,4-dichloro electron-withdrawing substituent on the phenyl ring exhibited the strongest inhibition effect against AChE, with an IC50 value of 77.15 µM. Overall, the adamantyl-based ester with the mono-substituent at position 3 of the phenyl ring exhibited good AChE inhibition effects with an ascending order for the substituents: Cl < NO2 < CH3 < OCH3. Furthermore, compounds with electron-withdrawing groups (Cl and NO2) substituted at position 3 on their phenyl rings demonstrated stronger AChE inhibition effects, in comparison to their respective positional isomers. On the other hand, compound 2j with a 3-methoxyphenyl ring showed the highest inhibition effect against BChE, with an IC50 value of 223.30 µM. Molecular docking analyses were conducted for potential AChE and BChE inhibitors, and the results demonstrated that the peripheral anionic sites of target proteins were predominant binding sites for these compounds through hydrogen bonds and halogen interactions instead of hydrophobic interactions in the catalytic active site.

Synthesis and Crystallographic Insight into the Structural Aspects of Some Novel Adamantane-Based Ester Derivatives.

Adamantyl-based compounds are commercially important in the treatments for neurological conditions and type-2 diabetes, aside from their anti-viral abilities. Their values in drug design are chronicled as multi-dimensional. In the present study, a series of 2-(adamantan-1-yl)-2-oxoethyl benzoates, 2(a-q), and 2-(adamantan-1-yl)-2-oxoethyl 2-pyridinecarboxylate, 2r, were synthesized by reacting 1-adamantyl bromomethyl ketone with various carboxylic acids using potassium carbonate in dimethylformamide medium at room temperature. Three-dimensional structures studied using X-ray diffraction suggest that the adamantyl moiety can serve as an efficient building block to synthesize 2-oxopropyl benzoate derivatives with synclinal conformation with a looser-packed crystal packing system. Compounds 2a, 2b, 2f, 2g, 2i, 2j, 2m, 2n, 2o, 2q and 2r exhibit strong antioxidant activities in the hydrogen peroxide radical scavenging test. Furthermore, three compounds, 2p, 2q and 2r, show good anti-inflammatory activities in the evaluation of albumin denaturation.

6-Cyanona-phthalen-2-yl 4-hexyl-benzo-ate.

In the title compound, C24H23NO2, a whole mol-ecule is disordered over two sets of sites with occupancies in a ratio of 0.692 (6):0.308 (6). In the major disorder component, the naphthalene ring system forms a dihedral angle of 68.6 (5)° with the benzene ring. The corresponding angle in the minor component is 81.6 (10)°. In the crystal, mol-ecules are linked into chains propagating along the b-axis direction via weak C-H⋯O hydrogen bonds. The crystal packing is further consolidated by weak C-H⋯π inter-actions.

Crystal structure of (E)-4-{2-[4-(all-yloxy)phen-yl]diazen-yl}benzoic acid.

The title compound, C16H14N2O3, has an E conformation about the azo-benzene [-N=N- = 1.2481 (16) Å] linkage. The benzene rings are almost coplanar [dihedral angle = 1.36 (7)°]. The O atoms of the carb-oxy-lic acid group are disordered over two sets of sites and were refined with an occupancy ratio of 0.5:0.5. The two disordered components of the carb-oxy-lic acid group make dihedral angles of 1.5 (14) and 3.8 (12)° with the benzene ring to which they are attached. In the crystal, mol-ecules are linked via pairs of O-H⋯O hydrogen bonds, forming inversion dimers. The dimers are connected via C-H⋯O hydrogen bonds, forming ribbons lying parallel to [120]. These ribbons are linked via C-H⋯π inter-actions, forming slabs parallel to (001).

6-(Hex-5-en-yloxy)naphthalene-2-carb-oxy-lic acid.

The asymmetric unit of the title compound, C17H18O3, comprises three independent mol-ecules with similar geometries. In each mol-ecule, the carbonyl group is twisted away from the napthalene ring system, making dihedral angles of 1.0 (2), 1.05 (19)° and 1.5 (2)°. The butene group in all three mol-ecules are disordered over two sets of sites, with a refined occupancy ratio of 0.664 (6):0.336 (6). In the crystal, mol-ecules are oriented with respect to their carbonyl groups, forming head-to-head dimers via O-H⋯O hydrogen bonds. Adjacent dimers are further inter-connected by C-H⋯O hydrogen bonds into chains along the a-axis direction. The crystal structure is further stabilized by weak C-H⋯π inter-actions.

1-[4-(Prop-2-en-1-yl-oxy)benz-yl]-2-[4-(prop-2-en-1-yl-oxy)phen-yl]-1H-benzimidazole.

In the title compound, C26H24N2O2, the benzimidazole ring system is almost planar [maximum displacement = 0.025 (1) Å] and makes dihedral angles of 80.48 (5) and 41.57 (5)° with the benzene rings, which are inclined to one another by 65.33 (6)°. In the crystal, mol-ecules are linked via C-H⋯π and weak π-π inter-actions [centroid-centroid distance = 3.8070 (7) Šand inter-planar distance = 3.6160 (5) Å].

rac-[3-Hydroxy-6,9-dimethyl-6-(4-methylpent-3-en-1-yl)-6a,7,8,9,10,10a-hexahydro-6H-1,9-epoxybenzo[c]chromen-4-yl](phenyl)methanone.

The title compound congestiflorone, C(28)H(32)O(4), which was isolated from the stem bark of Mesua congestiflora, consists of a benzophenone skeleton with two attached pyran rings to which a cyclo-hexane ring and a C6 side chain are bonded. The benzene ring is significantly distorted from planarity (r.m.s. deviation = 0.0007 Å) due to the constraints imposed by junctions with the two pyran rings. The cyclo-hexane ring is in a chair conformation, one pyran ring is in a boat conformation, while the other is a distorted chair. The phenyl and benzene rings make a dihedral angle of 55.85 (9)°. An intra-molecular O-H⋯O hydrogen bond is observed. In the crystal, mol-ecules are linked via C-H⋯O inter-actions.

4-{(E)-2-[4-(But-3-en-1-yl-oxy)phen-yl]diazen-1-yl}benzoic acid.

The title compound, C(17)H(16)N(2)O(3), has an E conformation about the azobenzene (-N=N-) linkage. The benzene rings are twisted slightly with respect to each other [6.79 (9)°], while the dihedral angle between the plane through the carb-oxy group and the attached benzene ring is 3.2 (2)°. In the crystal, mol-ecules are oriented with the carb-oxy groups head-to-head, forming O-H⋯O hydrogen-bonded inversion dimers. These dimers are connected by C-H⋯O hydrogen-bonds into layers lying parallel to the (013) plane.

4-(Dodec-yloxy)benzonitrile.

In the title compound, C(19)H(29)NO, the C-C and C-N bond distances of the benzonitrile group are 1.445 (2) and 1.157 (2) Å, respectively. The aliphatic fragment adopts a bent zigzag arangement which differs from the planar zigzag arrangement normally observed in n-alkanes or long-chain alkyl-benzenes. In the crystal, inversion dimers linked by pairs of C-H⋯O hydrogen bonds occur. A C-H⋯N inter-action also occurs. In the crystal, mol-ecules are packed with the nitrile and aliphatic groups oriented in a head-to-tail fashion involving, forming a ripple-like motif along the a axis.

(20S*,24S*)-25-Hy-droxy-20,24-ep-oxy-A-homo-4-oxadammaran-3-one (Chrysura) isolated from the leaves of Walsura chrysogyne.

The title dammarane triterpenoid, C(30)H(50)O(4), assigned the name chrysura, was isolated from an ethyl acetate extract of Walsura chrysogyne leaves (Meliaceae). It has 20S*,24S* relative stereochemistry and an oxepanone ring with two methyl groups at position 4. The two cyclo-hexane rings adopt chair conformations. The cyclo-pentane and tetra-hydro-furan rings have envelope conformations; their mean planes make a dihedral angle of 13.1 (3)°, indicating that the rings are only slightly tilted with respect to each other. There is an intra-molecular C-H⋯O hydrogen bond in the mol-ecule, which forms S(6) and S(7) ring motifs. In the crystal, mol-ecules are linked via O-H⋯O and C-H⋯O hydrogen bonds, forming chains propagating along [001] which stack along the b-axis direction.

4-Hexyl-oxybenzamide.

In the title compound, C(13)H(19)NO(2), the dihedral angle between the benzene ring and the plane throught the non-H atoms of the amide group is 29.3 (1)°. The benzene ring and the alkane carbon skeleton plane are twisted slightly with respect to each other [5.40 (5)°]. In the crystal, mol-ecules are oriented with the amide groups head-to-head, forming N-H⋯O hydrogen-bonded dimers. The dimers are connected by further N-H⋯O hydrogen bonds into a ladder-like motif along the b axis.

Caloxanthone C: a pyran-oxanthone from the stem bark of Calophyllum soulattri.

THE TITLE COMPOUND [SYSTEMATIC NAME: 5,10-di-hy-droxy-2,2-di-methyl-12-(2-methyl-but-3-en-2-yl)-pyrano[3,2-b]xanthen-6(2H)-one], C(23)H(22)O(5), isolated from the stem bark of Calophyllum soulattri, consists of four six-membered rings and a 2-methyl-but-3-en-2-yl side chain. The tricyclic xanthone ring system is almost planar [maximum deviation = 0.093 (2) Å], whereas the pyran-oid ring is in a distorted boat conformation. The 2-methyl-but-3-en-2-yl side chain is in a synperiplanar conformation. There are two intra-molecular O-H⋯O hydrogen bonds. In the crystal, mol-ecules are linked by C-H⋯O inter-actions, forming a zigzag chain propagating in [010].

[rac-1,8-Bis(2-carbamoyleth-yl)-5,5,7,12,12,14-hexa-methyl-1,4,8,11-tetra-aza-cyclo-tetra-deca-ne]copper(II) di-acetate tetra-hydrate: crystal structure and Hirshfeld surface analysis.

The title CuII macrocyclic complex salt tetra-hydrate, [Cu(C22H46N6O2)](C2H3O2)2·4H2O, sees the metal atom located on a centre of inversion and coordinated within a 4 + 2 (N4O2) tetra-gonally distorted coordination geometry; the N atoms are derived from the macrocycle and the O atoms from weakly associated [3.2048 (15) Å] acetate anions. Further stability to the three-ion aggregate is provided by intra-molecular amine-N-H⋯O(carboxyl-ate) hydrogen bonds. Hydrogen bonding is also prominent in the mol-ecular packing with amide-N-H⋯O(amide) inter-actions, leading to eight-membered {⋯HNCO}2 synthons, amide-N-H⋯O(water), water-O-H⋯O(carboxyl-ate) and water-O-H⋯O(water) hydrogen bonds featuring within the three-dimensional architecture. The calculated Hirshfeld surfaces for the individual components of the asymmetric unit differentiate the water mol-ecules owing to their distinctive supra-molecular association. For each of the anion and cation, H⋯H contacts predominate (50.7 and 65.2%, respectively) followed by H⋯O/O⋯H contacts (44.5 and 29.9%, respectively).

1-{(E)-[4-(4-Hy-droxy-phen-yl)butan-2-yl-idene]amino}-3-phenyl-thio-urea: crystal structure, Hirshfeld surface analysis and computational study.

The title thio-urea derivative, C17H19N3OS, adopts a U-shaped conformation with the dihedral angle between the terminal aromatic rings being 73.64 (5)°. The major twist in the mol-ecule occurs about the ethane bond with the Ci-Ce-Ce-Cb torsion angle being -78.12 (18)°; i = imine, e = ethane and b = benzene. The configuration about the imine bond is E, the N-bound H atoms lie on opposite sides of the mol-ecule and an intra-molecular amine-N-H⋯N(imine) hydrogen bond is evident. In the mol-ecular packing, hydroxyl-O-H⋯S(thione) and amine-N-H⋯O hydrogen bonding feature within a linear, supra-molecular chain. The chains are connected into a layer in the ab plane by a combination of methyl-ene-C-H⋯S(thione), methyl-ene-C-H⋯O(hydrox-yl), methyl-C-H⋯π(phen-yl) and phenyl-C-H⋯π(hy-droxy-benzene) inter-actions. The layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surface highlights the presence of weak methyl-C-H⋯O(hydrox-yl) and H⋯H inter-actions in the inter-layer region. Computational chemistry indicates that dispersion energy is the major contributor to the overall stabilization of the mol-ecular packing.

Bis{N'-[3-(4-nitro-phen-yl)-1-phenyl-prop-2-en-1-yl-idene]-N-phenyl-carbamimido-thio-ato}zinc(II): crystal structure, Hirshfeld surface analysis and computational study.

The title zinc bis-(thio-semicarbazone) complex, [Zn(C22H17N4O2S)2], comprises two N,S-donor anions, leading to a distorted tetra-hedral N2S2 donor set. The resultant five-membered chelate rings are nearly planar and form a dihedral angle of 73.28 (3)°. The configurations about the endocyclic- and exocyclic-imine bonds are Z and E, respectively, and that about the ethyl-ene bond is E. The major differences in the conformations of the ligands are seen in the dihedral angles between the chelate ring and nitro-benzene rings [40.48 (6) cf. 13.18 (4)°] and the N-bound phenyl and nitro-benzene ring [43.23 (8) and 22.64 (4)°]. In the crystal, a linear supra-molecular chain along the b-axis direction features amine-N-H⋯O(nitro) hydrogen bonding. The chains assemble along the 21-screw axis through a combination of phenyl-C-H⋯O(nitro) and π(chelate ring)-π(phen-yl) contacts. The double chains are linked into a three-dimensional architecture through phenyl-C-H⋯O(nitro) and nitro-O⋯π(phen-yl) inter-actions.

Di-n-but-yl[N'-(3-meth-oxy-2-oxidobenzyl-idene)-N-phenyl-carbamohydrazono-thio-ato]tin(IV): crystal structure, Hirshfeld surface analysis and computational study.

The title diorganotin Schiff base derivative, [Sn(C4H9)2(C15H13N3O2S)], features a penta-coordinated tin centre defined by the N,O,S-donor atoms of the di-anionic Schiff base ligand and two methyl-ene-C atoms of the n-butyl substituents. The resultant C2NOS donor set defines a geometry inter-mediate between trigonal-bipyramidal and square-pyramidal. In the crystal, amine-N-H⋯O(meth-oxy) hydrogen bonding is found in a helical, supra-molecular chain propagating along the b-axis direction. The chains are assembled into a layer parallel to (01) with methyl-ene-C-H⋯π(phen-yl) inter-actions prominent; layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surface showed the presence of weak methyl-ene-C-H⋯π(phen-yl) inter-actions and short H⋯H contacts in the inter-layer region. Consistent with the nature of the identified contacts, the stabilization of the crystal is dominated by the dispersion energy term.

3,5-Bis(4-hy-droxy-phen-yl)-4H-1,2,4-triazol-4-amine monohydrate.

The triazole ring in the title compound, C(14)H(12)N(4)O(2)·H(2)O, makes dihedral angles of 36.9 (1) and 37.3 (1)° with the two benzene rings. Each hy-droxy group is a hydrogen-bond donor to a two-coordinate N atom of an adjacent mol-ecule; these O-H⋯N hydrogen bonds generate a layer parallel to the ab plane. Adjacent layers are linked by N--H⋯O and O(water)-H⋯O hydrogen bonds into a three-dimensional network.

12-Acetyl-6-hy-droxy-3,3,9,9-tetra-methyl-furo[3,4-b]pyrano[3,2-h]xanthene-7,11(3H,9H)-dione.

The title compound, Artonol B, C(24)H(20)O(7), isolated from the stem bark of Artocarpus kemando, consists of four six-membered rings and one five-membered ring. The tricyclic xanthone ring system is almost planar [maximum deviation 0.115 (5) Å], whereas the pyran-oid ring is in a distorted boat conformation·The furan ring is almost coplanar with the fused aromatic ring, making a dihedral angle of 3.76 (9)°. The phenol ring serves as a intra-molecular hydrogen-bond donor to the adjacent carbonyl group and also acts as an inter-molecular hydrogen-bond acceptor for the methyl groups of adjacent mol-ecules, forming a three-dimensional network in the crystal.