Crystal structure determination and analyses of Hirshfeld surface, crystal voids, inter-molecular inter-action energies and energy frameworks of 1-benzyl-4-(methyl-sulfan-yl)-3a,7a-di-hydro-1H-pyrazolo-[3,4-d]pyrimidine.

The pyrazolo-pyrimidine moiety in the title mol-ecule, C13H12N4S, is planar with the methyl-sulfanyl substituent lying essentially in the same plane. The benzyl group is rotated well out of this plane by 73.64 (6)°, giving the mol-ecule an approximate L shape. In the crystal, C-H⋯π(ring) inter-actions and C-H⋯S hydrogen bonds form tubes extending along the a axis. Furthermore, there are π-π inter-actions between parallel phenyl rings with centroid-to-centroid distances of 3.8418 (12) Å. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (47.0%), H⋯N/N⋯H (17.6%) and H⋯C/C⋯H (17.0%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 76.45 Å3 and 6.39%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the cohesion of the crystal structure is dominated by the dispersion energy contributions.

Crystal structure, Hirshfeld surface analysis, calculations of inter-molecular inter-action energies and energy frameworks and the DFT-optimized mol-ecular structure of 1-[(1-butyl-1H-1,2,3-triazol-4-yl)meth-yl]-3-(prop-1-en-2-yl)-1H-benzimidazol-2-one.

The benzimidazole entity of the title mol-ecule, C17H21N5O, is almost planar (r.m.s. deviation = 0.0262 Å). In the crystal, bifurcated C-H⋯O hydrogen bonds link individual mol-ecules into layers extending parallel to the ac plane. Two weak C-H⋯π(ring) inter-actions may also be effective in the stabilization of the crystal structure. Hirshfeld surface analysis of the crystal structure reveals that the most important contributions for the crystal packing are from H⋯H (57.9%), H⋯C/C⋯H (18.1%) and H⋯O/O⋯H (14.9%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the most dominant forces in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization of the title compound is dominated via dispersion energy contributions. The mol-ecular structure optimized by density functional theory (DFT) at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state.

Crystal structure, Hirshfeld surface analysis, calculations of crystal voids, inter-action energy and energy frameworks as well as density functional theory (DFT) calculations of 3-[2-(morpholin-4-yl)eth-yl]-5,5-di-phenyl-imidazolidine-2,4-dione.

In the title mol-ecule, C21H23N3O3, the imidazolidine ring slightly deviates from planarity and the morpholine ring exhibits the chair conformation. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds form helical chains of mol-ecules extending parallel to the c axis that are connected by C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis reveals that the most important contributions for the crystal packing are from H⋯H (55.2%), H⋯C/C⋯H (22.6%) and H⋯O/O⋯H (20.5%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 236.78 Å3 and 12.71%, respectively. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the nearly equal electrostatic and dispersion energy contributions. The DFT-optimized mol-ecular structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. Moreover, the HOMO-LUMO behaviour was elucidated to determine the energy gap.

Crystal structure and Hirshfeld surface analysis of (Z)-N-{chloro-[(4-ferrocenylphen-yl)imino]-meth-yl}-4-ferrocenylaniline N,N-di-methyl-formamide monosolvate.

The title mol-ecule, [Fe2(C5H5)2(C23H17ClN2)]·C3H7NO, is twisted end to end and the central N/C/N unit is disordered. In the crystal, several C-H⋯π(ring) inter-actions lead to the formation of layers, which are connected by further C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (60.2%) and H⋯C/C⋯H (27.0%) inter-actions. Hydrogen bonding, C-H⋯π(ring) inter-actions and van der Waals inter-actions dominate the crystal packing.

Crystal structure, Hirshfeld surface analysis, crystal voids, inter-action energy calculations and energy frameworks, and DFT calculations of 1-(4-methyl-benz-yl)in-do-line-2,3-dione.

The in-do-line portion of the title mol-ecule, C16H13NO2, is planar. In the crystal, a layer structure is generated by C-H⋯O hydrogen bonds and C-H⋯π(ring), π-stacking and C=O⋯π(ring) inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (43.0%), H⋯C/C⋯H (25.0%) and H⋯O/O⋯H (22.8%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. The volume of the crystal voids and the percentage of free space were calculated to be 120.52 Å3 and 9.64%, respectively, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated by the dispersion energy contributions in the title compound. Moreover, the DFT-optimized structure at the B3LYP/6-311G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state.

Crystal structure, Hirshfeld surface analysis, crystal voids, inter-action energy calculations and energy frameworks and DFT calculations of ethyl 2-cyano-3-(3-hy-droxy-5-methyl-1H-pyrazol-4-yl)-3-phen-yl-propano-ate.

The title compound, C16H17N3O3, is racemic as it crystallizes in a centrosymmetric space group (P ), although the trans disposition of substituents about the central C-C bond is established. The five- and six-membered rings are oriented at a dihedral angle of 75.88 (8)°. In the crystal, N-H⋯N hydrogen bonds form chains of mol-ecules extending along the c-axis direction that are connected by inversion-related pairs of O-H⋯N into ribbons. The ribbons are linked by C-H⋯π(ring) inter-actions, forming layers parallel to the ab plane. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (45.9%), H⋯N/N⋯H (23.3%), H⋯C/C⋯H (16.2%) and H⋯O/O⋯H (12.3%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. The volume of the crystal voids and the percentage of free space were calculated to be 100.94 Å3 and 13.20%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the electrostatic energy contributions in the title compound. Moreover, the DFT-optimized structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Crystal structure, Hirshfeld surface and crystal void analysis, inter-molecular inter-action energies, DFT calculations and energy frameworks of 2H-benzo[b][1,4]thia-zin-3(4H)-one 1,1-dioxide.

In the title mol-ecule, C8H7NO3S, the nitro-gen atom has a planar environment, and the thia-zine ring exhibits a screw-boat conformation. In the crystal, corrugated layers of mol-ecules parallel to the ab plane are formed by N-H⋯O and C-H⋯O hydrogen bonds together with C-H⋯π(ring) and S=O⋯π(ring) inter-actions. The layers are connected by additional C-H⋯O hydrogen bonds and π-stacking inter-actions. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯O/O⋯H (49.4%), H⋯H (23.0%) and H⋯C/C⋯H (14.1%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated as 75.4 Å3 and 9.3%. Density functional theory (DFT) computations revealed N-H⋯O and C-H⋯O hydrogen-bonding energies of 43.3, 34.7 and 34.4 kJ mol-1, respectively. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via the electrostatic energy contribution. Moreover, the DFT-optimized structure at the B3LYP/ 6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Synthesis, crystal structure and Hirshfeld surface analysis of 1-(12-bromo-dodec-yl)indoline-2,3-dione.

In the title compound, C20H28BrNO2, the indoline portion is almost planar and the 12-bromo-dodecyl chain adopts an all-trans conformation apart from the gauche terminal C-C-C-Br fragment. A micellar-like structure is generated in the crystal by C-H⋯O hydrogen bonds and π-stacking inter-actions between indolinedione head groups and inter-calation of the 12-bromo-dodecyl tails. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (58.9%), H⋯O/O⋯H (17.9%) and H⋯Br/Br⋯H (9.5%) contacts. A density functional theory (DFT) optimized structure at the B3LYP/ 6-311 G(d,p) level shows good agreement with the experimentally determined mol-ecular structure in the solid state.

Crystal structure, Hirshfeld surface analysis, inter-action energy and energy framework calculations, as well as density functional theory (DFT) com-putation, of methyl 2-oxo-1-(prop-2-yn-yl)-1,2-di-hydro-quinoline-4-carboxyl-ate.

In the title mol-ecule, C14H11NO3, the di-hydro-quinoline core deviates slightly from planarity, indicated by the dihedral angle of 1.07 (3)° between the two six-membered rings. In the crystal, layers of mol-ecules almost parallel to the bc plane are formed by C-H⋯O hydro-gen bonds. These are joined by π-π stacking inter-actions. A Hirshfeld surface analysis revealed that the most important contributions to the crystal packing are from H⋯H (36.0%), H⋯C/C⋯H (28.9%) and H⋯O/O⋯H (23.5%) inter-actions. The evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the dispersion energy contribution. Moreover, the mol-ecular structure optimized by density functional theory (DFT) at the B3LYP/6-311G(d,p) level is com-pared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

One-Pot Synthesis of Cyclomatrix-Type Polyphosphazene Microspheres and Their High Thermal Stability.

Highly cross-linked inorganic and organic hybrid cyclomatrix-polyphosphazenes microspheres (C-PPZs) have been successfully synthesized by a one-pot polymerization technique between hexachlorocyclotriphosphazene and p-phenylenediamine in the presence of triethylamine (TEA), and they were used for enhancing the flame retardancy of epoxy resins (EPs). A thermoset EP was prepared by incorporating different percentages (2, 5, and 10%) of C-PPZs into diglycidyl ether of bisphenol A (DGEBA). The results reveal that the size and morphology of the microspheres can be tuned by varying the synthesis temperature. The average size of C-CPPZs gradually increased from 3.1, 4.9, to 7.8 µm as the temperature was increased from 100, 120, to 200 °C, respectively. The thermogravimetric analysis showed that the C-CPPZ microspheres have good thermal stability up to 900 °C with about ∼10 wt % mass loss for C-CPPZs formed at 200 °C compared to ∼30 wt % mass loss for those obtained at 100 and 120 °C. The 10% loss at 900 °C is much lower than the previous research concerning the thermal stability of cyclophosphazene, in which more weight losses were observed at lower temperatures. The resulting C-CPPZ microspheres were characterized by spectroscopic and imaging techniques including Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental mapping, and X-ray photoelectron spectroscopy.

Crystal structure, Hirshfeld surface analysis, inter-molecular inter-action energies, energy frameworks and DFT calculations of 4-amino-1-(prop-2-yn-1-yl)pyrimidin-2(1H)-one.

In the title mol-ecule, C7H7N3O, the pyrimidine ring is essentially planar, with the propynyl group rotated out of this plane by 15.31 (4)°. In the crystal, a tri-periodic network is formed by N-H⋯O, N-H⋯N and C-H⋯O hydrogen-bonding and slipped π-π stacking inter-actions, leading to narrow channels extending parallel to the c axis. Hirshfeld surface analysis of the crystal structure reveals that the most important contributions for the crystal packing are from H⋯H (36.2%), H⋯C/C⋯H (20.9%), H⋯O/O⋯H (17.8%) and H⋯N/N⋯H (12.2%) inter-actions, showing that hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the electrostatic energy contributions. The mol-ecular structure optimized by density functional theory (DFT) calculations at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined structure in the solid state. The HOMO-LUMO behaviour was also elucidated to determine the energy gap.

Multiscale Structure of Starches Grafted with Hydrophobic Groups: A New Analytical Strategy.

Starch, an abundant and low-cost plant-based glucopolymer, has great potential to replace carbon-based polymers in various materials. In order to optimize its functional properties for bioplastics applications chemical groups need to be introduced on the free hydroxyl groups in a controlled manner, so an understanding of the resulting structure-properties relationships is therefore essential. The purpose of this work was to study the multiscale structure of highly-acetylated (degree of substitution, 0.4 < DS ≤ 3) and etherified starches by using an original combination of experimental strategies and methodologies. The molecular structure and substituents repartition were investigated by developing new sample preparation strategies for specific analysis including Asymmetrical Flow Field Flow Fractionation associated with Multiangle Laser Light Scattering, Nuclear Magnetic Resonance (NMR), Raman and Time of Flight Secondary Ion Mass spectroscopies. Molar mass decrease and specific ways of chain breakage due to modification were pointed out and are correlated to the amylose content. The amorphous structuration was revealed by solid-state NMR. This original broad analytical approach allowed for the first time a large characterization of highly-acetylated starches insoluble in aqueous solvents. This strategy, then applied to characterize etherified starches, opens the way to correlate the structure to the properties of such insoluble starch-based materials.

Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of (S)-10-propargyl-pyrrolo-[2,1-c][1,4]benzodiazepine-5,11-dione.

The title compound, C15H14N2O2, consists of pyrrole and benzodiazepine units linked to a propargyl moiety, where the pyrrole and diazepine rings adopt half-chair and boat conformations, respectively. The absolute configuration was assigned on the the basis of l-proline, which was used in the synthesis of benzodiazepine. In the crystal, weak C-HBnz⋯ODiazp and C-HProprg⋯ODiazp (Bnz = benzene, Diazp = diazepine and Proprg = proparg-yl) hydrogen bonds link the mol-ecules into two-dimensional networks parallel to the bc plane, enclosing R 4 4(28) ring motifs, with the networks forming oblique stacks along the a-axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (49.8%), H⋯C/C⋯H (25.7%) and H⋯O/O⋯H (20.1%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, C-H⋯O hydrogen-bond energies are 38.8 (for C-HBnz⋯ODiazp) and 27.1 (for C-HProprg⋯ODiazp) kJ mol-1. Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Crystal structure of 5-bromo-1-ethyl-indoline-2,3-dione.

The title compound, C10H8BrNO2, crystallizes with two independent molcules (A and B) in the asymmetric unit. In each mol-ecule, the indoline ring system is almost planar, with the largest deviation from the mean plane being 0.016 (2) Šin mol-ecule A and 0.040 (13) Šin mol-ecule B. In each mol-ecule, the ethyl group is nearly perpendicular to the indoline ring system with C-C-N-C torsion angles of -94.8 (3) and 93.0 (3)° in mol-ecules A and B, respectively. In the crystal, the two mol-ecules are inclined to each other, making a dihedral angle of 6.28 (8)°. In the molecular packing, the A and B mol-ecules are linked by C-H⋯O hydrogen bonds, forming -A-B-A-B- chains along [01-1]. Parallel chains are linked via a weak slipped parallel π-π inter-action [inter-centroid distance = 3.6107 (14) Å] and a short Br⋯O contact [3.183 (2) Å], forming a three-dimensional structure.

6-Bromo-1,3-bis-[(1,3-dioxolan-2-yl)meth-yl]-1H-imidazo[4,5-b]pyridin-2(3H)-one.

In the title compound, C14H16BrN3O5, the N atoms adjacent to the carbonyl group in the five-membered ring are substituted by (1,3-dioxolan-2-yl)methyl groups. The fused ring system is essentially planar, with the largest deviation from the mean plane being 0.014 (2) Šfor the C atom bearing the Br atom. The first oxolane ring, attached on the side of the N atom belonging to the pyridine ring, has an envelope conformation with one of the O atoms as the flap, whereas the second oxolane ring displays a twisted boat conformation. The two oxolane rings display envelope and twisted boat conformations. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, building chains parallel to the a-axis direction.

1,3-Bis(prop-2-yn-1-yl)-1H-anthra[1,2-d]imidazole-2,6,11(3H)-trione.

In the title compound, C21H12N2O3, the fused-ring system is roughly planar, the largest deviation from the mean plane being 0.084 (2) Å. The two prop-2-yn-1-yl groups are almost perpendicular to the fused ring plane, making C-C-N-C torsion angles of -103.4 (2) and -105.3 (2)°, and point in opposite directions with respect to the plane. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming a three-dimensional network.

3-Benzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one.

The fused imidazole and pyridine rings in the title compound, C13H10BrN3O, are linked to a benzyl group. The fused ring system is essentially planar, the largest deviation from the mean plane being 0.006 (2) Å. The phenyl ring is not coplanar with the fused ring system, as indicated by the dihedral angle of 67.04 (12)°. In the crystal, mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming inversion dimers.

1-Allyl-3-benzyl-1H-benzimidazol-2(3H)-one.

In the title compound, C17H16N2O, the fused benzimidazol-2(3H)-one system is essentially planar, the largest deviation from the mean plane being 0.006 (2) Šfor the carbonyl C atom. Its mean plane is almost perpendicular to the benzyl plane and to the allyl group, making dihedral angles of 80.6 (1) and 77.4 (3)°, respectively. The benzyl group and the allyl subsituent lie on opposite sides of the fused ring system. In the crystal, mol-ecules are linked by bifurcated C-H⋯O hydrogen bonds in which the carbonyl O atom acts as accepter to two aromatic C-H groups, forming a two-dimensional network parallel to (001).

The infrared and Raman spectra of ethylammonium hexafluorosilicate [C2H5NH3]2SiF6.

The X-rays powder diffraction pattern of [C2H5NH3]2SiF6 was obtained and indexed on the basis of a hexagonal unit cell. The vibrational spectra (IR and Raman) of this compound were recorded and discussed in relation to the above-mentioned crystal structure. The vibrational spectra of the cations indicate that they are disordered and hydrogen bonded to the anions. On the opposite, the Raman spectrum of the anions could be interpreted in terms of ordered groups. The combination bands observed in the 2300-1800 cm(-1) spectral region in the IR spectrum indicate that this compound may contain C-NH3 groups.

Structure and vibrational study of the trimethylammonium hexafluorosilicate [(CH3)3NH]2SiF6 compound.

The X-ray powder diffraction pattern of [(CH(3))(3)NH](2)SiF(6) was obtained and indexed on the basis of a centred cubic unit cell with the P4(1)32 as the likely space group. The Infrared and Raman spectra of this compound have been recorded at room temperature and discussed in relation to the crystal structure. In this salt, the bands corresponding to the cation vibrational modes show that the symmetry of these cations is distorted from the free C(3v) one and that they are strongly hydrogen-bonded to the respective anions. However, the spectra of the anions can be interpreted in term of ordered groups as indicated by the splitting of the bands corresponding to some degenerate vibrational modes. The harmonic frequencies, corresponding to the (CH(3))(3)NH-SiF(6)-NH(CH(3))(3) optimised geometry, were calculated using the SCF semi-empirical MNDO-PM3 method.