5-[(4-Bromophenyl)diazenyl]-2-{2-[1-(1H-indol-3-yl)ethylidene]hydrazinyl}-4-methylthiazole dimethylformamide hemisolvate

The asymmetric unit of the title compound, 2C20H17BrN6S·C3H7NO, comprises two molecules of the thiazole derivative and one molecule of dimethylformamide (DMF) solvent. The twist angles between the planes through the bromophenyl, methylthiazolyl and indolyl groups are 10.1 (1) and 44.2 (1)°, respectively, for one molecule and 11.3 (1) and 1.6 (1)° for the other. In the crystal, N—H...N hydrogen bonds link four of the main molecules into tetramers. N—H...O bonds involving the DMF solvent molecule also occur.

Fabrication of Novel Ball-Like Polystyrene Films Containing Schiff Base Microspheres as Photostabilizers

Polystyrene films containing a low concentration of three highly aromatic Schiff bases were prepared using the casting method. The polystyrene films were irradiated with ultraviolet light (300 h). The polystyrene infrared spectra, weight loss, molecular weight reduction and the surface morphology were examined upon irradiation. The Schiff bases acted as photostabilizers and reduced the photodegradation of polystyrene films to a significant level in comparison to the blank film. The images recorded of the surface of the miscible polystyrene/Schiff base blends showed novel ball-like microspheres with a diameter of 3.4⁻4.3 µm. The Schiff bases were able to endow excellent protection to polystyrene against ultraviolet irradiation.

5-Methyl-1-(4-methylphenyl)-N′-[1-(thiophen-2-yl)ethylidene]-1H-1,2,3-triazole-4-carbohydrazide

The asymmetric unit comprises a single molecule of C17H17N5OS with twist angles between the planes through the thiophenyl, methyltriazolyl and tolyl groups of 12.3 (1) and 44.9 (1)°, respectively. A possible weak intramolecular hydrogen bond forms between the methyl substituent on the triazole ring and the adjacent carbonyl O atom. In the crystal structure, π–π interactions occur between phenyl rings of pairs of molecules related by inversion symmetry with a centroid–centroid separation of 3.7647 (18) Å. The shortest intermolecular hydrogen bonding contact is a C—H...O interaction that generates inversion dimers.

Insights about the Absence of Rb Cation from the 3D Perovskite Lattice: Effect on the Structural, Morphological, and Photophysical Properties and Photovoltaic Performance

Efficiencies >20% are obtained from the perovskite solar cells (PSCs) employing Cs⁺ and Rb⁺ based perovskite compositions; therefore, it is important to understand the effect of these inorganic cations specifically Rb⁺ on the properties of perovskite structures. Here the influence of Cs⁺ and Rb⁺ is elucidated on the structural, morphological, and photophysical properties of perovskite structures and the photovoltaic performances of resulting PSCs. Structural, photoluminescence (PL), and external quantum efficiency studies establish the incorporation of Cs⁺ (x < 10%) but amply rule out the possibility of Rb-incorporation into the MAPbI₃ (MA = CH₃ NH₃⁺ ) lattice. Moreover, morphological studies and time-resolved PL show that both Cs⁺ and Rb⁺ detrimentally affect the surface coverage of MAPbI₃ layers and charge-carrier dynamics, respectively, by influencing nucleation density and by inducing nonradiative recombination. In addition, differential scanning calorimetry shows that the transition from orthorhombic to tetragonal phase occurring around 160 K requires more thermal energy for the Cs-containing MAPbI₃ systems compared to the pristine MAPbI₃ . Investigation including mixed halide (I/Br) and mixed cation A-cation based compositions further confirms the absence of Rb⁺ from the 3D-perovskite lattice. The fundamental insights gained through this work will be of great significance to further understand highly promising perovskite compositions.

Ethyl 2-anilino-4-methyl-5-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazole-4-carbonyl]thiophene-3-carboxylate

The conformation of the title compound, C25H24N4O3S, is influenced by an intramolecular N—H...O hydrogen bond, which generates an S(6) ring. The twist angles between the planes through the toluyl, methyltriazole, thiophene and phenyl rings are 60.1 (1), 33.5 (1) and 39.9 (1)°, respectively. In the crystal, molecules are stacked along the a-axis direction with weak aromatic π–π stacking interactions occurring between the thiophene rings [centroid-to-centroid distance = 3.7285 (15) Å].

5-Methyl-1-(4-methylphenyl)-N′-[1-(1H-pyrrol-2-yl)ethylidene]-1H-1,2,3-triazole-4-carbohydrazide monohydrate

In the title hydrate, C17H18N6O·H2O, the twist angles between the least-squares planes of the pyrolyl/methyltriazolyl/tolyl groups are 11.4 (2) and 7.9 (1)°, respectively. In the crystal, centrosymmetric tetramers (two organic molecules and two water molecules) are linked by N—H...O and O—H...O hydrogen bonds. Weak aromatic π–π stacking interactions between the triazolyl rings [centroid–centroid separation = 3.6422 (10) Å] link the tetramers.

Sodium 1-(4-chlorophenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylate

In the title molecular salt, Na+·C10H7ClN3O2 −, the dihedral angles between the planes of adjacent chlorophenyl, methyltriazole and carboxylate groups of the anion are 50.2 (1) and 9.0 (3)°, respectively. The shortest distance between sodium cations is 4.0595 (9) Å. The sodium cation is coordinated by two N atoms and three O atoms, generating layers of ions lying parallel to the bc plane.

Fabrication of ordered honeycomb porous poly(vinyl chloride) thin film doped with a Schiff base and nickel(II) chloride

A modified poly(vinyl chloride) honeycomb thin film containing a low concentration of a thiadiazole Schiff base and nickel(II) chloride was successfully fabricated using the casting process. The surface morphology of the synthesized thin film was investigated using the scanning electronic microscopy. The synthesized poly(vinyl chloride) thin film was found to have a homogeneous surface morphology with a high crystalline nature. The addition of nickel(II) chloride was discovered to be vital for the formation of the honeycomb like structure.

Crystal structure of (E)-N′-(4-methoxybenzylidene)-5-methyl-1-(4-tolyl)-1H-1,2,3-triazole-4-carbohydrazide, C19H19N5O2

C19H19N5O2, triclinic, P1̄ (no. 2), a = 6.6320(3) Å, b = 10.3272(5) Å, c = 13.0832(6) Å, α = 102.751(2)°, β = 96.130(2)°, γ = 103.079(2)°, V = 839.63(7) Å3, Z = 2, R gt = 0.0553, wR ref(F2 ) = 0.1521, T = 100(2) K.

Crystal structure of (E)-3-(3-(5-methyl-1-4-tolyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-4-yl)-1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)prop-2-en-1-one, C31H26N8O

C31H26N8O, triclinic, P1̄ (no. 2), a = 6.6046(3) Å, b = 15.1056(8) Å, c = 15.2115(8) Å, α = 61.996(2)°, β = 80.390(3)°, γ = 87.579(2)°, V = 1319.97(12) Å3, Z = 2, R int = 0.108, wR(F 2) = 0.143, T = 296(2) K.

Poly(vinyl Chloride) Photostabilization in the Presence of Schiff Bases Containing a Thiadiazole Moiety

Five Schiff bases containing a thiadiazole moiety have been used as poly(vinyl chloride) photostabilizers at low concentrations. The efficiency of Schiff bases as photostabilizers was investigated using various techniques, for example, the changes in poly(vinyl chloride) infrared spectra, molecular weight, chain scission quantum yield, and surface morphology were monitored upon irradiation with an ultraviolet light. Evidently, all the additives used inhibited poly(vinyl chloride) photodegradation at a significant level. The most efficient Schiff base exhibited a high level of aromaticity and contained a hydroxyl group. It seems possible that such photostabilization could be due to the direct absorption of ultraviolet radiation by the additives. In addition, Schiff bases could act as radical scavengers and proton transfer facilitators to stabilize the polymeric materials.

(E)-1-(4-Bromophenyl)-3-[3-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one

In the title compound, C27H20BrN5O, the dihedral angle between the heterocyclic rings is 10.2 (2)°. The phenyl ring bound to the triazole ring is disordered over two orientations in a 0.808 (4):0.192 (4) ratio. In the crystal, C—H...O interactions form chains along [010]. π–π interactions are observed between the phenyl–pyrazolyl unit and the phenylene group of a neighbouring molecule.

Ethyl 1-phenyl-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxylate

The non-H atoms of the title molecule, C19H16N2O2, are almost coplanar (r.m.s. deviation = 0.019 Å), apart from the phenyl group, which is disordered with two components of almost equal occupancy: the dihedral angle between them is 78.9 (3)°. In the crystal, weak C—H...N hydrogen bonds link the molecules into [001] chains and aromatic π–π stacking interactions [shortest centroid–centroid separation = 3.747 (2) Å] form columns parallel to the c-axis direction.

(E)-3-(4-Fluorophenyl)-1-[1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl]prop-2-en-1-one

The asymmetric unit of the title compound, C18H13F2N3O, comprises two molecules with similar conformations. In the crystal, weak C—H...F interactions form chains of molecules and the chains are stacked to form layers parallel to (101).

The Effect of Ultraviolet Irradiation on the Physicochemical Properties of Poly(vinyl Chloride) Films Containing Organotin(IV) Complexes as Photostabilizers

Three organotin(IV) complexes containing ciprofloxacin as a ligand (Ph₃SnL, Me₂SnL₂ and Bu₂SnL₂; 0.5% by weight) were used as additives to inhibit the photodegradation of polyvinyl chloride films (40 µm thickness) upon irradiation with ultraviolet light (λmax = 313 at a light intensity = 7.75 × 10-7 ein dm-3 S-1) at room temperature. The efficiency of organotin(IV) complexes as photostabilizers was determined by monitoring the changes in the weight, growth of specific functional groups (hydroxyl, carbonyl and carbene), viscosity, average molecular weight, chain scission and degree of deterioration of the polymeric films upon irradiation. The results obtained indicated that organotin(IV) complexes stabilized poly(vinyl chloride) and the dimethyltin(IV) complex was the most efficient additive. The surface morphologies of poly(vinyl chloride) films containing organotin(IV) complexes were examined using an atomic force microscope and scanning electron microscopy. These showed that the surface of polymeric films containing organotin(IV) complexes were smoother and less rough, compared to the surface of the blank films. Some mechanisms that explained the role of organotin(IV) complexes in poly(vinyl chloride) photostabilization process were proposed.

(E)-2-Benzoyl-3-[1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl]acrylonitrile

The asymmetric unit of the title compound, C23H15N3OS, consists of two crystallographically independent molecules, which are related by a pseudo-inversion centre. In one molecule, the pyrazolyl ring makes dihedral angles of 35.7 (4), 19.1 (1) and 47.3 (1)°, respectively, with the thiophenyl ring, the attached phenyl ring and the phenyl ring of the benzoyl group. In the second molecule, the corresponding values are 37.4 (1), 16.1 (1) and 48.2 (1)°, respectively. In the crystal, the two independent molecules are linked to each otherviaa π–π interaction between the pyrazolyl rings [centroid–centroid distance = 3.578 (12) Å]. Weak intermolecular C—H...O interactions are also observed. The thiophenyl ring of one molecule is disordered over two orientations, with a refined occupancy ratio of 0.768 (3):0.232 (3).

4-(4-Bromophenyl)-2-(3-(4-chlorophenyl)-5-{3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-1-phenyl-1H-pyrazol-4-yl}-4,5-dihydro-1H-pyrazol-1-yl)thiazole

In the title compound, C37H28BrClN8O, the linked chlorophenyl, pyrazolyl and thiazolyl ringss are almost coplanar, with dihedral angles of 0.6 (3)° between the chlorophenyl and pyrazolyl rings and 5.4 (3)° between the pyrazolyl and thiazolyl rings. The dihedral angle between the thiazolyl and bromophenyl rings is 17.5 (2)°. The central pyrazolyl rings subtend a dihedral angle of 67.7 (1)°. In the crystal, π–π and C—H...Br interactions link the molecules to form columns parallel to [010]. The π–π interactions involve partially overlapping nonparallel bromophenyl and tolyl groups.

2-({6-[5-Methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]imidazo[2,1-b]thiazol-5-yl}methylidene)hydrazinecarbothioamide dimethylformamide 0.25-solvate

The asymmetric unit of the title solvate, C17H16N8S2·0.25C3H7NO, consists of two C17H16N8S2 molecules and a dimethylformamide molecule disordered about a crystallographic inversion centre. Both triazole molecules feature an intramolecular C—H...N interaction, which generates an S(6) ring in each case. In the crystal, the components are linked by N—H...N and N—H...S hydrogen bonds to form [001] chains, which are cross-linked by weak C—H...O, C—H...N and C—H...S interactions.

Ethyl (Z)-2-[2-(4-methylphenyl)hydrazin-1-ylidene]-3-oxo-3-(thiazol-2-ylamino)propanoate

In the title compound, C15H16N4O3S, the dihedral angle between the aromatic rings is 15.90 (19)°. The molecule features two intramolecular N—H...O hydrogen bonds, which both close S(6) rings. In the crystal, weak C—H...O interactions link the molecules into [010] chains.

Methyl 5-(1-benzofuran-2-yl)isoxazole-3-carboxylate

The title compound, C13H9NO4, is almost planar (r.m.s. deviation = 0.071 Å). In the crystal, weak C—H...O and C—H...N interactions connect the molecules into ribbons propagating parallel to thea-axis direction.

1-[5-Methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]ethanone

In the title compound, C12H13N3O, thep-tolyl ring is twisted away from the mean plane (r.m.s. deviation = 0.044 Å) of the rest of the molecule by 50.84 (6)°. In the crystal, molecules are linked by C—H...π interactions, forming zigzag chains propagating in theb-axis direction.

Crystal structure of 3-(2-bromophenyl)-1,1-dimethylthiourea, C9H11BrN2S

C9H11BrN2S, orthorhombic, P212121 (no. 19), a = 7.5187(3) Å, b = 8.0634(3) Å, c = 17.5320(6) Å, V = 1062.90(7) Å3, Z = 4, R gt(F) = 0.0216, wR ref(F 2) = 0.0536, T = 296(2) K.

Crystal structure of 1,1-dimethyl-3-(2-phenylethyl)urea, C11H16N2O

C11H16N2O, orthorhombic, Pbca (no. 61), a = 10.7388(6) Å, b = 9.8449(5) Å, c = 21.1259(14) Å, V = 2233.5(2) Å3, Z = 8, Rgt(F) = 0.0582, wRref(F2) = 0.1795, T = 293 K.