Synthesis, X-ray structure, antimicrobial activity, DFT and molecular docking studies of N-(thiophen-2-ylmethyl)thiophene-2-carboxamide.

In the present study, N-(thiophen-2-ylmethyl)thiophene-2-carboxamide, C10H9NOS2, (I), was obtained by the reaction of thiophene-2-carbonyl chloride and thiophen-2-ylmethanamine. Characterization of (I) was carried out using X-ray diffraction, spectroscopic techniques and elemental analyses. The DFT/B3LYP/6-311++G(d,p) theoretical level was successfully applied to calculate the optimized geometry and the local and global chemical activity parameters. The results obtained show good agreement between the experimental and theoretical geometrical parameters. The local and global chemical activity parameters were examined to determine the electrophilic and nucleophilic sites in (I). The natural bond orbital (NBO) analysis of (I) gives an efficient methodology for investigating the inter- and intramolecular bonding, as well as giving a convenient basis for investigating charge transfer or conjugative interactions in molecular systems. Also, the antimicrobial activity of (I) was investigated against eight microorganisms using the microdilution method and it is found to have an effective antibacterial activity. In addition, molecular docking studies were calculated in order to understand the nature of the binding of (I) with a lung cancer protein (PDB entry 1x2j).

Synthesis, Structural Investigation, Hirshfeld Surface Analysis, and Biological Evaluation of N-(3-Cyanothiophen-2-yl)-2-(thiophen-2-yl)acetamide.

In this study, a novel heterocyclic amide derivative, N-(3-cyanothiophen-2-yl)-2-(thiophen-2-yl)acetamide (I), was obtained by reacting 2-aminothiophene-3-carbonitrile with activated 2-(thiophen-2-yl)acetic acid in a N-acylation reaction and characterized by elemental analyses, FT-IR, 1H and 13C NMR spectroscopic studies, and single crystal X-ray crystallography. The crystal packing of I is stabilized by C-H···N and N-H···N hydrogen bonds. In addition, I was investigated computationally using the density functional theory (DFT) method with the B3LYP exchange and correlation functions in conjunction with the 6311++G(d,p) basis set in the gas phase. Fukui function (FF) analysis was also carried out. Electrophilicity-based charge transfer (ECT) method and charge transfer (ΔN) were computed to examine the interactions between I and DNA bases (such as guanine, thymine, adenine, and cytosine). The most important contributions to the Hirshfeld surface are H···H (21%), C···H (20%), S···H (19%), N···H (14%), and O···H (12%). An ABTS antioxidant assay was used to evaluate the in vitro antioxidant activity of I. The compound exhibited moderate antioxidant activity. The antimicrobial activity of the title molecule was investigated under aseptic conditions, using the microdilution method, against Gram-positive and Gram-negative bacterial strains, and it also demonstrated significant activity against yeasts (Candida glabrata ATCC 90030, Candida krusei ATCC 34135). The findings revealed that the molecule possesses significant antioxidant and antimicrobial properties.

Experimental and theoretical investigations on a furan-2-carboxamide-bearing thiazole: synthesis, molecular characterization by IR/NMR/XRD, electronic characterization by DFT, Hirshfeld surface analysis and biological activity.

A thiazole-based heterocyclic amide, namely, N-(thiazol-2-yl)furan-2-carboxamide, C8H6N2O2S, was synthesized and investigated for its antimicrobial activity. The structure was characterized by elemental analysis and IR, 1H NMR, and 13C NMR spectroscopy. The molecular and electronic structures were investigated experimentally by single-crystal X-ray diffraction (XRD) and theoretically by density functional theory (DFT) modelling. The compound crystallized in the monoclinic space group P21/n and the asymmetric unit contains two symmetrically independent molecules. Several noncovalent interactions were recorded by XRD and analysed with Hirshfeld surface analysis (HSA) calculations. Natural bond orbital, molecular electrostatic potential, second-order nonlinear optical and thermodynamic property analyses were also carried out using the DFT/B3LYP method. The title compound was evaluated for antimicrobial activity against eight microorganisms consisting of Gram-negative bacteria, Gram-positive bacteria and fungi. The compound showed good antimicrobial activity against the eight tested microorganisms. This suggests that the compound merits further study for potential pharmacological and medical applications.

Crystal structure of 3,4a,7,7,10a-penta-methyl-3-vinyl-dodeca-hydro-1H-benzo[f]chromen-9-ol isolated from Sideritis perfoliata.

The asymmetric unit of the title compound, C20H34O2, contains two crystallographically independent mol-ecules (1 and 2) with similar conformations. In both mol-ecules, the cyclo-hexane rings adopt a chair conformation, while the oxane rings are also puckered. In the crystal, O-H⋯O hydrogen bonds connect adjacent mol-ecules, forming C(6) helical chains located around a 21 screw axis and running along the crystallographic a axis. The packing of these chains is governed only by van der Waals inter-actions. Semi-empirical PM3 quantum chemical calculations are in a satisfactory agreement with the structural results of the X-ray structure analysis. The absolute structure was indeterminate in the present experiment.

Erratum: Crystal structure of racemic [(1R,2S,3R,4S,6S)-2,6-bis-(furan-2-yl)-4-hy-droxy-4-(thio-phen-2-yl)cyclo-hexane-1,3-di-yl]bis-(thio-phen-2-yl-methanone). Corrigendum.

[This corrects the article DOI: 10.1107/S2056989016009452.].

Crystal structure of racemic [(1R,2S,3R,4S,6S)-2,6-bis-(furan-2-yl)-4-hy-droxy-4-(thio-phen-2-yl)cyclo-hexane-1,3-di-yl]bis-(thio-phen-2-yl-methanone).

In the title compound, C28H22O5S3, the central cyclo-hexane ring adopts a chair conformation. The atoms of the furan ring attached to the 6-position of the central cyclo-hexane ring are disordered over two sets of sites with occupancies of 0.832 (5) and 0.168 (5). The hy-droxy group is disordered over two positions (at the 4- and 6-positions of the cyclo-hexane ring) in the ratio 0.832 (5):0.168 (5). In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and C-H⋯π inter-actions, forming layers parallel to (100).

The crystal structures of three 3-methyl-1H-1,2,4-triazole-5-thio-nes, including a second polymorph of 4-[(E)-(5-bromo-2-hy-droxy-benzyl-idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione and a redetermination of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione.

The structures of three 3-methyl-1H-1,2,4-triazole-5-thione derivatives are reported. The structure of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione, C3H6N4S, (I), has been redetermined with an improved model for the H atoms: the non-H atoms of (I) all lie on mirror planes in space group Pbcm, and the H atoms of the methyl group are disordered over two sets of reflection-related atomic sites having occupancy 0.5: two independent N-H⋯S hydrogen bonds link the mol-ecules of compound (I) into complex sheets. The non-H atoms in the mol-ecules of 4-[(E)-(3,4-di-meth-oxy-benzyl-idene)amino]-3-methyl-1H-1,2,4-tri-azol-5(4H)-thione, C12H14N4O2S, (II), despite lying in general positions are close to planar, with a dihedral angle between the two rings of 6.31 (10)°: the mol-ecules of compound (II) are linked by a three-centre N-H⋯(O)2 hydrogen bond into a C(10)C(11)[R 1 (2)(5)] chain of rings. A second polymorph of 4-[(E)-(5-bromo-2-hy-droxy-5-bromo-benzyl-idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione, C10H9BrN4OS, (III), has been identified; the non-H atoms are nearly co-planar with a dihedral angle between the two rings of 1.9 (4)°. There is an intra-molecular O-H⋯N hydrogen bond and the mol-ecules are linked by N-H⋯S hydrogen bonds, forming centrosymmetric R 2 (2)(8) dimers. Comparisons are made with some related structures.

Dihydrooxazolones and dihydroimidazolones derived from acylglycines: syntheses, molecular structures and supramolecular assembly.

Syntheses and structures are described for some alkylidene-substituted dihydrooxazolones and dihydroimidazoles derived from simple acylglycines. A second, triclinic, polymorph of 4-benzylidene-2-(4-methylphenyl)-1,3-oxazol-5(4H)-one, C17H13NO2, (I), has been identified and the structure of 2-methyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one, C9H7NO2S, (II), has been rerefined taking into account the orientational disorder of the thienyl group in each of the two independent molecules. The reactions of phenylhydrazine with 2-phenyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one or 2-(4-methylphenyl)-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one yield, respectively, 3-anilino-2-phenyl-5-[(thiophen-2-yl)methylidene]-3,5-dihydro-4H-imidazol-4-one, C10H15N3OS, (III), and 3-anilino-2-(4-methylphenyl)-5-[(thiophen-2-yl)methylidene]-3,5-dihydro-4H-imidazol-4-one, C21H17N3OS, (IV), which both exhibit orientational disorder in their thienyl groups. The reactions of 2-phenyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one with hydrazine hydrate or with water yield, respectively, N-[3-hydrazinyl-3-oxo-1-(thiophen-2-yl)prop-1-en-2-yl]benzamide and 2-(benzoylamino)-3-(thiophen-2-yl)prop-2-enoic acid, which in turn react, respectively, with thiophene-2-carbaldehyde to form 2-phenyl-5-[(thiophen-2-yl)methylidene]-3-{[(E)-(thiophen-2-yl)methylidene]amino}-3,5-dihydro-4H-imidazol-4-one, C19H13N3OS2, (V), which exhibits orientational disorder in only one of its thienyl groups, and with methanol to give methyl (2Z)-2-(benzoylamino)-3-(thiophen-2-yl)prop-2-enoate, C15H13NO3S, (VI). There are no direction-specific intermolecular interactions in the crystal structure of the triclinic polymorph of (I), but the molecules of (II) are linked by two independent C-H···O hydrogen bonds to form C2(2)(14) chains. Compounds (III) and (IV) both form centrosymmetric R2(2)(10) dimers built from N-H···O hydrogen bonds, while compound (V) forms a centrosymmetric R2(2)(10) dimer built from C-H···O hydrogen bonds. In the structure of compound (VI), a combination of N-H···O and C-H···π(arene) hydrogen bonds links the molecules into sheets. Comparisons are made with some similar compounds.

A chalcone showing positional disorder, two related diarylcyclohexenones showing enantiomeric disorder and a related hydroxyterphenyl, all derived from simple carbonyl precursors.

Four compounds are reported, all of which lie along a versatile reaction pathway which leads from simple carbonyl compounds to terphenyls. (2E)-1-(2,4-Dichlorophenyl)-3- [4-(prop-1-en-2-yl)phenyl]prop-2-en-1-one, C18H14Cl2O, (I), prepared from 4-(prop-1-en-2-yl)benzaldehyde and 2,4-dichloroacetophenone, exhibits disorder over two sets of atomic sites having occupancies of 0.664 (6) and 0.336 (6). The related chalcone (2E)-3-(4-chlorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one reacts with acetone to produce (5RS)-3-(4-chlorophenyl)-5-[4-(propan-2-yl)phenyl]cyclohex-2-en-1-one, C21H21ClO, (II), which exhibits enantiomeric disorder with occupancies at the reference site of 0.662 (4) and 0.338 (4) for the (5R) and (5S) forms; the same chalcone reacts with methyl 3-oxobutanoate to give methyl (1RS,6SR)-4-(4-chlorophenyl)-6-[4-(propan-2-yl)phenyl]-2-oxocyclohex-3-ene-1-carboxylate, C23H23ClO3, (III), where the reference site contains both (1R,6S) and (1S,6R) forms with occupancies of 0.923 (3) and 0.077 (3), respectively. Oxidation, using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, of ethyl (1RS,6SR)-6-(4-bromophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate, prepared in a similar manner to (II) and (III), produces ethyl 4''-bromo-4-fluoro-5'-hydroxy-1,1':3',1''-terphenyl-4'-carboxylate, C21H16BrFO3, (IV), which crystallizes with Z' = 2 in the space group P-1. There are no significant intermolecular interactions in the structures of compounds (I) and (II), but for the major disorder component of compound (III), the molecules are linked into sheets by a combination of C-H...O and C-H...π(arene) hydrogen bonds. The two independent molecules of compound (IV) form two different centrosymmetric dimers, one built from inversion-related pairs of C-H...O hydrogen bonds and the other from inversion-related pairs of C-H...π(arene) hydrogen bonds. Comparisons are made with related compounds.

Molecular structure, spectroscopic investigations, second-order nonlinear optical properties and intramolecular proton transfer of (E)-5-(diethylamino)-2-[(4-propylphenylimino)methyl]phenol: a combined experimental and theoretical study.

This work presents a combined experimental and theoretical study on an ortho-hydroxy Schiff base compound, (E)-5-(diethylamino)-2-[(4-propylphenylimino)methyl]phenol. The crystal structure and spectroscopic properties of the compound have been determined by using X-ray diffraction, IR and UV-vis spectroscopy techniques. The electronic structure, vibrational frequencies and electronic absorption spectra have been investigated from the calculative point of view. A relaxed potential energy surface scan has been performed based on the optimized geometry of OH tautomeric form to describe the potential energy barrier belonging to intramolecular proton transfer and to observe the effects of transfer on the molecular geometry. The second-order nonlinear optical properties have been investigated based on the first static hyperpolarizability (ß) by using the density functional theory.

(2-Hydroxyethyl)hydrazinium(2+) dichloride.

The crystal structure of the title compound, C2H10N2O(2+).2Cl-, is built up from one 2-hydroxyethylhydrazinium(2+) cation and two Cl- anions. The molecular structure is stabilized by O-H...Cl and N-H...Cl hydrogen bonds. The crystal structure is stabilized by one N-H...O and three N-H...Cl interactions, and the three-dimensional network of hydrogen bonds stabilizes the crystal packing. All five hydrazinium H atoms are involved in hydrogen bonds to Cl- anions. The Cl...H contact distances range from 2.122 (15) to 2.809 (14) A.

N-cinnamoylsaccharin.

The title compound [systematic name: 2-cinnamoyl-1,2-benzisothiazol-3(2H)-one 1,1-dioxide], C16H11NO4S, contains both saccharin and cinnamoyl groups. The molecule is approximately planar in the solid state, and adjacent molecules are connected by C-H...O and C-H...pi(phenyl) interactions. In the C-H...pi interaction, the C...CgA distance is 3.916 (4) A (CgA is the non-fused benzene ring centroid) and the C-H...pi angle is 156 (2) degrees . A feature of the molecular geometry is the narrow C-S-N angle of 92.51 (9) degrees in the five-membered ring. This angle relieves strain from the ring and makes it possible for the whole saccharin group to become quite planar.

3-Methoxy-5-(4-methylphenyldiazenyl)salicylaldehyde and 3-methoxy-5-(2-methylphenyldiazenyl)salicylaldehyde.

The two title molecules, both C(15)H(14)N(2)O(3), are roughly planar and display a trans conformation with respect to the -N=N- double bond, as found for other diazene derivatives. In both compounds, there are intramolecular O-H.O hydrogen bonds and the crystal packing is governed by weak intermolecular C-H.O hydrogen bonds and pi-pi stacking.

4-[(2-Chlorophenyl)diazenyl]-6-methoxy-2-[[tris(hydroxymethyl)methyl]aminomethylene]cyclohexa-3,5-dien-1(2H)-one.

The structure of the title compound, C(18)H(20)ClN(3)O(5), displays the characteristic features of azobenzene derivatives. Intramolecular N-H.O, weak intramolecular C-H.O, and intermolecular O-H.O and C-H.O interactions influence the conformation of the molecules and the crystal packing. Intermolecular hydrogen bonds link the molecules into infinite chains, and the title compound adopts the keto-amine tautomeric form. The azobenzene moiety of the molecule has a trans configuration. The molecule is not planar, and the dihedral angle between the two phenyl rings is 35.6 (2) degrees.

2-[(2-hydroxy-4-nitrophenyl)aminomethylene]cyclohexa-3,5-dien-1(2H)-one.

The title compound, C(13)H(10)N(2)O(4), adopts the keto-amine tautomeric form and displays an intramolecular N-H...O [N...O = 2.579 (2) A] and three intermolecular O-H...O [O...O = 2.561 (2) A] and C-H...O [C...O = 3.274 (2) and 3.318 (2) A] hydrogen bonds. The keto-amine structure is favoured by through-molecule conjugation between the hydroxy O atom and imine N atom. The dihedral angle between the planes of the two aromatic rings is 10.79 (4) degrees.