Search

The title compound, 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, molecules 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 interactions, forming a three-dimensional network. No significant π–π interactions are observed.

This work focuses on the first use of ultrasonic phenol-ene coupling as a polymer analogous transformation. The ultrasonic reaction was introduced into chitin chemistry, resulting in the fast and convenient preparation of new water-soluble cationic chitin derivatives. Since water-soluble derivatives of fully deacetylated chitin are poorly described in the literature, the synthesis of each new type of these derivatives is a significant event in polysaccharide chemistry. Polycations, or cationic polymers, are of particular interest as antibacterial agents. Consequently, the resulting polymers were tested for their antibacterial activity and toxicity. We found that the highly substituted polymer of medium molecular weight exhibited the most pronounced in vitro antibacterial effect. We prepared nanoparticles using the ionic gelation technique. The most effective in vitro antibacterial chitin-based systems were tested in vivo in rats. These tests demonstrated outstanding antibacterial effects combined with an absence of toxicity. Additionally, we found that the resulting polymers, unlike their nanoparticle counterparts, also exhibited strong antioxidant effects. In summary, we demonstrated the effectiveness of ultrasound in polymer chemistry and highlighted the importance of the sonochemical approach in the chemical modification of polysaccharides. This approach enables the synthesis of derivatives with improved physicochemical and biological properties.

In the title compound, C6H8N2OS, all atoms except for the methyl H atoms are coplanar, with a maximum deviation of 0.026 (4) Å. In the crystal, pairs of molecules are linked by N—H...N hydrogen bonds, forming R22(8) ring motifs. Dimers are connected by N—H...O hydrogen bonds, forming layers parallel to the (102) plane. Consolidating the molecular packing, these layers are connected by C—H...π interactions between the center of the 1,3-thiazole ring and the H atom of the methyl group attached to it, as well as C=O...π interactions between the center of the 1,3-thiazole ring and the O atom of the carboxyl group. According to a Hirshfeld surface study, H...H (37.6%), O...H/H...O (16.8%), S...H/H...S (15.4%), N...H/H...N (13.0%) and C...H/H...C (7.6%) interactions are the most significant contributors to the crystal packing.

In the hydrated title salt, C7H12N5S2+·Cl−·H2O, the asymmetric unit comprises one 2-amino-5-{(1E)-1-[(carbamothioylamino)imino]ethyl}-4-methyl-1,3-thiazol-3-ium cation, one chloride anion and one water molecule of crystallization. The cation is nearly flat (r.m.s. deviation of non-H atoms is 0.0814 Å), with the largest deviation of 0.1484 (14) Å observed for one of the methyl C atoms. In the crystal, the cations are linked by O—H...Cl, N—H...Cl, N—H...O, N—H...S and C—H...S hydrogen bonds, forming a tri-periodic network. The most important contributions to the crystal packing are from H...H (35.4%), S...H/H...S (24.4%), N...H/H...N (8.7%), Cl...H/H...Cl (8.2%) and C...H/H...C (7.7%) interactions.

The copper catalyzed reaction of N-monosubstituted hydrazones with carbon tetrabromide leads to formation of expected dibromodiazadienes and unexpected dibromostyrenes. The experimental and theoretical study of the reaction revealed a key role of N-centered radicals, which can eliminate aryl radicals to form the corresponding dibromostyrenes. Alternatively, the oxidation of intermediate N-centered radicals by Cu(II) results in the corresponding diazadienes. These two reaction pathways are competitive directions of the reaction. Consequently, the reaction can be useful for the synthesis of both dibromostyrenes and rare dibromodiazadienes.

In the cation of the title salt, C17H18N3S+·Br−·C3H7NO, the central thiazolidine ring adopts an envelope conformation with puckering parameters Q(2) = 0.310 (3) Å and φ(2) = 42.2 (6)°. In the crystal, each cation is connected to two anions by N—H... Br hydrogen bonds, forming an R42(8) motif parallel to the (10\overline{1}) plane. van der Waals interactions between the cations, anions and N,N-dimethylformamide molecules further stabilize the crystal structure in three dimensions. The most important contributions to the surface contacts are from H...H (55.6%), C...H/H...C (17.9%) and Br...H/H...Br (7.0%) interactions, as concluded from a Hirshfeld analysis.

In the crystal of the title compound, C7H5FN4S, the molecules are non-planar, with dihedral angle formed by least-squares planes of tetrazole and benzene rings of 59.94 (8) °. The crystal packing is formed by N—H...S hydrogen bonds, which link the molecules into centrosymmetric dimers with an R22(8) ring motif, and by the offset face-to-face π–π stacking interactions between the benzene rings, which join the dimers into layers parallel to (100). The Hirshfeld surface analysis shows that the most important contributions to the surface contacts are from N...H/H...N (21.9%), S...H/H...S (21.1%), H...H (14.6%), F...H/H...F (11.8%) and C...H/H...C (9.5%) interactions.

In the title compound, C25H20O2, the central cyclohexenone ring adopts an envelope conformation. The mean plane of the cyclohexenone ring makes dihedral angles of 87.66 (11) and 23.76 (12)°, respectively, with the two attached phenyl rings, while it is inclined by 69.55 (11)° to the phenyl ring of the benzoyl group. In the crystal, the molecules are linked by C—H...O and C—H...π interactions, forming a three-dimensional network.

The central thiazolidine ring of the title salt, C16H16N3S+·Br−, adopts an envelope conformation, with the C atom bearing the phenyl ring as the flap atom. In the crystal, the cations and anions are linked by N—H...Br hydrogen bonds, forming chains parallel to the b-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H...H (46.4%), C...H/H...C (18.6%) and H...Br/Br...H (17.5%) interactions.

Nitro functionalized dibromodiazadiene dyes were prepared and fully characterized including X-ray single crystal analysis. Electron deficient dibromodiazadienes were found to be able to act as donors of halogen bonding (XB), while the nitro group acted as an acceptor of the XB. Depending on the substituents, the Br···O XB competed with other weak interactions, and for some of the dyes, they even outcompeted the XB involving the nitro group. However, the nitro functionalized dibromoalkenes 6a and 10a, which had only the nitro moiety as the most plausible acceptor of the XB, reliably formed 1D chains via Br⋯O XB. Experimental work was supported by the DFT calculations and topological analysis of the electron density distribution within the framework of Bader’s theory (QTAIM method).

In the cation of the title salt, C9H12N3S+·Br−, the thiazolidine ring adopts an envelope conformation with the C atom adjacent to the phenyl ring as the flap. In the crystal, N—H...Br hydrogen bonds link the components into a three-dimensional network. Weak π–π stacking interactions between the phenyl rings of adjacent cations also contribute to the molecular packing. A Hirshfeld surface analysis was conducted to quantify the contributions of the different intermolecular interactions and contacts.

The title salt, C16H15ClN3S+·Br−, is isotypic with (E)-3-[(4-fluorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide [Khalilov et al. (2019). Acta Cryst. E75, 662–666]. In the cation of the title salt, the atoms of the phenyl ring attached to the central thiazolidine ring and the atom joining the thiazolidine ring to the benzene ring are disordered over two sets of sites with occupancies of 0.570 (3) and 0.430 (3). The major and minor components of the disordered thiazolidine ring adopt slightly distorted envelope conformations, with the C atom bearing the phenyl ring as the flap atom. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N—H...Br hydrogen bonds, which are further connected by weak C—H...Br contacts into chains parallel to the a axis. Furthermore, not existing in the earlier report of (E)-3-[(4-fluorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide, C—H...π interactions and π–π stacking interactions [centroid-to-centroid distance = 3.897 (2) Å] between the major components of the disordered phenyl ring contribute to the stabilization of the molecular packing. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions for the crystal packing are from H...H (30.5%), Br...H/H...Br (21.2%), C...H/H...C (19.2%), Cl...H/H...Cl (13.0%) and S...H/H...S (5.0%) interactions.

In the cation of the title salt, C15H15N4S+·Br−·H2O, the central thiazolidine ring adopts an envelope conformation with puckering parameters Q(2) = 0.279 (4) Å and φ(2) = 222.5 (9)°. The mean plane of the thiazolidine ring makes dihedral angles of 12.4 (2) and 66.8 (3)° with the pyridine and phenyl rings, respectively. The pyridine ring in the title molecule is essentially planar (r.m.s deviation = 0.005 Å). In the crystal, the cations, anions and water molecules are linked into a three-dimensional network, which forms cross layers parallel to the (120) and (\overline{1}20) planes via O—H...Br, N—H...Br and N—H...N hydrogen bonds. C—H...π interactions also help in the stabilization of the molecular packing. Hirshfeld surface analysis and 2D (two-dimensional) fingerprint plots indicate that the most important contributions to the crystal packing are from H...H (35.5%), C...H/H...C (23.9%), Br...H/H...Br (16.4%), N...H/H...N (10.6%) and S...H/H...S (7.9%) interactions.

Novel halogenated aromatic dichlorodiazadienes were prepared via copper-mediated oxidative coupling between the corresponding hydrazones and CCl4. These rare azo-dyes were characterized using 1H and 13C NMR techniques and X-ray diffraction analysis for five halogenated dichlorodiazadienes. Multiple non-covalent halogen···halogen interactions were detected in the solid state and studied by DFT calculations and topological analysis of the electron density distribution within the framework of Bader’s theory (QTAIM method). Theoretical studies demonstrated that non-covalent halogen···halogen interactions play crucial role in self-assembly of highly polarizable dichlorodiazadienes. Thus, halogen bonding can dictate a packing preference in the solid state for this class of dichloro-substituted heterodienes, which could be a convenient tool for a fine tuning of the properties of this novel class of dyes.

We report an unprecedented multicomponent reaction of acetoacetanilide with malononitrile leading to a structurally novel bicyclic product (9) in a high yield. The structure has been confirmed by X-ray crystallography and comparative Hirshfeld surface analysis of 5-cyano-2-hydroxy-2-methyl-N-phenyl-4-(yridine-4-yl)-6-(thiophen-2-yl)-3,4-dihydro-2H-pyran-3-carboxamide 2, 5-cyano-2-hydroxy-2-methyl-6-oxo-N-phenyl-4-(thiophen-2-yl)piperidine-3-carboxamide 4 and 2-(8-amino-7,8a-dicyano-1-imino-4a-methyl-3-oxo-2-phenyl-1,3,4,4a,5,8a-hexahydroisoquinolin-6(2H)-ylidene)-N-phenylacetamide 9.

In the title compound, C21H24BrNO4, the dihedral angle between the heterocyclic ring and the pendant aromatic ring is 80.20 (13)°. The hexahydroquinone [i.e. the one with the C=O group] ring adopts a sofa conformation. An intramolecular O—H...O hydrogen bond generates an S(6) ring motif. The ethyl group is disordered over two sets of sites with a refined site occupancy ratio of 0.633 (10):0.366 (10). In the crystal, molecules are linked by N—H...O interactions, forming chains parallel to [101]. There are no significant C—H...π or π–π interactions in the crystal structure.

The title molecule, C21H25NO7, has four stereogenic centres and crystallized as a racemate. It consists of enantiomeric pairs with the relative configuration rac-(1R*,2S*,3R*). The cyclohexenone ring adopts an envelope conformation; the dimethyl-substituted C atom lies 0.640 (1) Å out of the mean plane formed by the rest of the ring atoms (r.m.s. deviation = 0.016 Å). The oxacyclohexene ring adopts a half-chair conformation, the hydroxy- and carboxyl-substituted C atoms lying −0.336 (1) and 0.419 (1) Å, respectively, out of the mean plane formed by the rest of the ring atoms (r.m.s. deviation = 0.002 Å). In the crystal, O—H...O hydrogen bonds link the molecules into a chain along the c-axis direction.

The title compound, [Cu(C4H2Cl6N3)2], was obtained by the reaction of CCl3CN with ammonia in presence of CuCl. The CuII atom is located about an inversion centre. The molecule consists of three planar units (one central square CuN4 and two C2N3 fragments), adopting a staircase-like structure. The six-membered metallocycles have a sofa conformation with the Cu atom out of the plane of the 1,3,5-triazapentadienyl ligands by 0.246 (5) Å. The ipso-C atoms of the CCl3 substituents are slightly out of the 1,3,5-triazapentadienyl planes by 0.149 (6) and −0.106 (6) Å. The CCl3 groups of each 1,3,5-triazapentadienyl ligand are practically in the energetically favourable mutually eclipsed conformation. In the crystal, the molecules are packed in stacks along the a axis. The molecules in the stacks are held together by two additional axial Cu...Cl interactions of 3.354 (2) Å. Taking the axial Cu...Cl interactions into account, the CuII atom exhibits a distorted [4 + 2]-octahedral coordination environment. The stacks are bound to each other by weak intermolecular attractive Cl...Cl [3.505 (2)–3.592 (3) Å] interactions.

In the title compound, C21H25NO3, the hydropyridine ring that constitutes a part of the hexahydroquinoline fused-ring system adopts a sofa conformation; the methine C atom deviates from the least-squares plane defined by the remaining five non-H atoms (r.m.s. deviation = 0.088 Å) by 0.454 (3) Å. The phenyl ring is aligned at 85.5 (1)° with respect to this mean plane. In the crystal, adjacent molecules are linked via an N—H...O hydrogen bond, involving the amino group and the carbonyl O atom of the fused-ring system, forming chains running along [100]. The ethyl group is disordered over two positions in a 0.609 (6):0.391 (6) ratio.

The cyclohexene ring that constitutes a part of the tetrahydroxanthene fused-ring system of the title compound, C23H26O4, adopts a flattened half-chair conformation that approximates an envelope conformation (in which the methylene C atom bearing the two methyl substituents represents the flap) as five of the six atoms lie approximately on a plane (r.m.s. deviation = 0.020 Å). The mean plane of the cyclohexene ring with the hydroxy substituent is approximately perpendicular to the mean plane of the tetrahydroxanthene system. In the crystal, adjacent molecules are linked by O—H...Ocarbonyl hydrogen bonds into a chain running along the b axis.

The CuII atom in the title compound, [Cu(C12H11N2O4)2(C10H14N2O)(H2O)]n, lies in a square plane defined by the O atoms of the carboxylate ions, the N atom of the N-heterocycle and the water molecule. Coordination by an amido O atom of an adjacent N-heterocycle in the apical direction leads to a polymeric chain running along [01-1]. The chain motif is consolidated by hydrogen bonds involving the water molecule; the water molecule is a hydrogen-bond donor to the free carbonyl atoms of the carboxylate ions. Intramolecular N—H...O hydrogen bonds also occur.

The complete molecule of the title compound, C28H38O2, is generated by a crystallographic centre of symmetry. The molecular conformation displays an intramolecular C—H...π interaction.

In the title compound, C17H19NO5, the cyclohexene ring is in a half-chair conformation and the isoxazole ring in an envelope conformation with the N atom as the flap. The C atoms in the 4- and 6-positions are of the same absolute configuration, whereas the C atom in the 5-position is of the opposite configuration, i.e. (4S*,5R*,6S*). The methyl fragment of the ethoxycarbonyl group at position 5 is disordered over two sets of sites in a 0.60:0.40 ratio. The crystal packing displays intermolecular N—H...O and O—H...O hydrogen bonds.

In the title compound, C6H12N2O2S, the heterocyclic ring has a sofa conformation. The molecular conformation is stabilized by an intramolecular O—H...O hydrogen-bond interaction with graph-set motif S(6). In the crystal, molecules are linked by O—H...S, N—H...S and N—H...O hydrogen-bond interactions, forming an extended two-dimensional framework parallel to the ac plane.

In the title compound, C16H25NO, the N-tert-butylpropanamide fragment is essentially planar, with the exception of two C atoms of the tert-butyl group (r.m.s. deviation = 0.005 Å), forming a dihedral angle of 84.09 (10)° with the plane of the mesityl fragment (r.m.s. deviation = 0.002 Å). The crystal packing is stabilized by an intermolecular N—H...O hydrogen bond, which links the molecules into chains with graph-set notation C(4) running parallel to the c axis.

In the title compound, [Cu(C8H4F3O2S)2(C10H14N2O)], the CuII atom exists in a distorted CuNO4 square-pyramidal geometry; the metal atom lies above a square plane defined by four O atoms of the two chelating anionic ligands, displaced in the direction of the axial occupant, the pyridine N atom, by 0.179 (1) Å. Weak intermolecular C—H...O and C—H...F hydrogen bonding is present in the crystal structure. One thienyl ring is disordered over two orientations in an occupancy ratio of 0.69 (1):0.31.

The molecule of the title compound, C22H26O2, exhibits Ci molecular symmetry with a crystallographic inversion centre at the mid-point of the central C—C bond. A kink in the molecule is defined by the torsion angle of 66.7 (2)° about this central bond of the alkyl bridge.

The title compound, [K(C17H18NO5)]n, reveals the relative configuration (4R*,5S*,6R*) whereas its crystals are racemic. The cyclohexane ring adopts a half-chair conformation and the isoxazole ring has an envelope conformation. The ethyl fragment of the ethoxycarbonyl group at position 5 is disordered in a 0.547 (7):0.453 (7) ratio. The K+ ion is surrounded by five O atoms from three ligands at distances ranging from 2.606 (2) to 3.028 (2) Å, generating a three-dimensional network. The crystal packing displays intermolecular O—H...N and O—H...O hydrogen bonds in which the hydroxy group acts as a double proton donor.

In the title compound, C20H26N2OS, four non-H atoms of the thiourea unit are approximately planar (r.m.s. deviation = 0.005 Å); the phenyl and benzene rings are twisted out of this plane by 28.55 (7) and 60.00 (7)°, respectively. An intramolecular N—H...O hydrogen bond occurs. The hydroxy group is hydrogen bonded to the double-bond S atom of an inversion-related molecule, generating a hydrogen-bonded dimer in the crystal structure.

The six-membered oxacyclohexene ring of the title compound, C13H14N2O2S, is fused with the benzene ring and the quarternary C atom lies above the plane of the benzene ring by 0.229 (8) Å, whereas the methine C atom (which bears the acetyl substituent) lies below this plane by 0.595 (8) Å. The oxacyclohexene ring is also fused with the sofa-shaped 2,6-diazacyclohexanone ring. The methine C atom that belongs to both six-membered rings lies above the mean plane of the other five atoms (r.m.s. deviation = 0.077 Å) by 0.759 (5) Å. In the crystal, N—H...S hydrogen bonds link adjacent molecules into a linear chain.

The title compound, C17H20N2O2, is chiral but crystallizes in a centrosymmetric space group as a racemate, the relative configuration at the stereogenic centres being 2S*,3R*,4S*. The cyclohexane ring adopts a half-chair conformation while the pyrazole ring has an envelope conformation. The crystal packing displays intermolecular O—H...N and N—H...O hydrogen bonding.

The title compound, C10H11Cl5O, is a chiral molecule with two stereogenic centres. However, it crystallizes as a racemate. One of enantiomers reveals the relative configuration (2S*,5R*). The cyclohexene ring adopts a half-chair conformation.

The methylaminopropyl chain in the title compound, C13H21NO, adopts an extended zigzag conformation and the N atom shows a trigonal coordination. The N atom acts as hydrogen-bond acceptor to the hydroxy group of an adjacent molecule, generating a helical chain running along the b axis. The amino H atom is not involved in hydrogen bonding.

In the title 2-propanol derivative, C17H27ClO2, the two tert-butyl groups both have one methyl C atom lying in the plane of the aromatic ring. In the crystal, the phenol group forms a hydrogen bond to the hydroxy O atom belonging to the alkyl substituent of an adjacent molecule, forming a chain along the ac diagonal. The Cl atom is disordered over two positions in a 0.73 (4):0.27 (4) ratio.

The title molecule, C21H30N2O5, is chiral with four stereogenic centres. The crystal is a racemate and consists of enantiomeric pairs with the relative configuration rac-(6S*,7R*,8R*,9S*). The ethyl fragment of the ethoxycarbonyl group at position 6 is disordered in a 0.46 (3):0.54 (3) ratio. The crystal structure features intermolecular N—H...O. Intramolecular O—H...N and N—H...O hydrogen bonds also occur.

In the title compound, C17H20N2O4·H2O, the cyclohexene ring adopts a half-chair conformation while the indazole ring is essentially planar [maximum deviation = 0.0192 (12) Å]. In the crystal, pairs of intermolecular O—H...N hydrogen bonds link the molecules into dimers lying about inversion centers and intramolecular O—H...O hydrogen bonds result in six-membered rings. The dimers are further connected by N—H...O and O—H...O hydrogen bonds.

In the title compound, C25H28N2O4, the cyclohexene ring adopts a half-chair conformation and the dihedral angle between the aromatic rings is 59.44 (11)°. In the crystal, a weak intermolecular N—H...O hydrogen bond occurs.

The title compound, C21H29NO6, is chiral with three stereogenic centres. The crystal is a racemate and consists of enantiomeric pairs with the relative configuration rac-(2R*,3S*,4R*). The ethyl fragment of the ethoxycarbonyl group at position 1 is disordered in a 0.60:0.40 ratio. The crystal packing displays intermolecular O—H...O hydrogen bonding. An intramolecular N—H...O hydrogen bond also occurs.

The structure of the title compound, C17H19NO3, is of interest with respect to antibacterial properties, antibiotic properties and biological activity. The structure displays intermolecular O—H...N hydrogen bonding.

The organic molecule in the title hydrate, C9H9N3O3·H2O, was obtained by the condenstation of salicylic aldehyde with urea in acetonitrile. The oxazine ring adopts a slightly distorted sofa conformation, with the N atom deviating from the plane passing through the other atoms of the ring by 0.267 (2) Å. The crystal structure displays intermolecular N—H...O and O—H...O hydrogen bonding.

The structure of the title compound, C17H21N2O2+·Cl−, is of interest with respect to its biological activity. The title compound comprises an organic cation and a chloride anion in the asymmetric unit. The positive charge is localized in a pyrazole moiety forming a pyrazolium cation. The structure displays intermolecular O—H...Cl and N—H...Cl hydrogen bonding.

In the title solvate, C30H24N4O2S·CH3CN, the substituted thiophene possesses approximate Cs(m) intrinsic symmetry, with the mirror plane passing through the S atom and the mid-point of the (Ph)C—C(Ph) bond. Despite the main backbone of the molecule being a long chain of conjugated bonds, it adopts a non-planar conformation due to the presence of various intra- and intermolecular hydrogen bonds. The hydrogen bonds result in twist configurations for both the amido and aminophenyl fragments relative to the central thiophene ring. There are two intramolecular Namine—H...O hydrogen bonds within the thiophene-2,5-dicarboxamide molecule that form seven-membered rings. In the crystal, the thiophene-2,5-dicarboxamide molecules form inversion dimers by four amide–amine N—H...N hydrogen bonds. The dimers are further linked into layers propagating in (100) both directly (via Namine—H...O hydrogen bonds) and through the acetonitrile solvate molecules (via amine–cyano N—H...N and CMe—H...O interactions).

The macrocycle of the title compound, C36H24N4O3S·2CHCl3, contains a rigid framework with the nitrogen and oxygen heteroatoms pointing in towards the center of the macrocyclic cavity. The macrocycle is essentially planar (r.m.s. deviation = 0.027 Å) except for the thiophene ring. The dihedral angle between the thiophene ring plane and the mean plane of the central macrocyclic core including all atoms except sulfur is 21.6 (1)°. Four intramolecular hydrogen bonds occur: two are between the amide hydrogen atoms and the Schiff base nitrogen atoms, while the others are between the amide hydrogen atoms and the sulfur atom of the thiophene. The two solvate chloroform molecules are bound to the carbonyl oxygen atoms of the ligand by weak C—H...O hydrogen bonding. In addition, the structure reveals intermolecular Cl...Cl close contacts [3.308 (2), 3.404 (2) and 3.280 (2) Å] between the chloroform solvate molecules. In the crystal, the macrocycles form layers parallel to (101), with an interlayer distance of 3.362 (3) Å. This short distance is determined by the stacking interactions between the amide carbonyl and imine fragments of neighboring ligands.