Dispersion Energy Contributions Research Articles

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.

N-Benzoyl-morpholine-4-carbothioamides: Crystal structures, Hirshfeld surface analysis, and Density functional theory calculations

The current research work describes facile synthesis, single crystal X-ray structures, Hirshfeld surface (HS) analysis, and density functional theory (DFT) calculations of two N-benzoyl-morpholine-4-carbothioamides (NDMC and NMMC). Consequently, the synthesized compounds, C12H12Cl2N2O2S (NDMC) and C13H16N2O2S (NMMC) crystallized in triclinic and monoclinic crystal systems each having respective space groups of P -1 and P 21, with corresponding a = 7.8045 (3) Å, b = 12.8458 (6) Å, c = 13.4946 (7) Å, α = 97.313 (4)°, β = 94.358 (4)°, γ = 93.348 (3)°, Z = 4 and V = 1334.84 (11) Å3 for compound (NDMC). Similarly, for compound (NMMC),a = 7.3322 (2) Å, b = 5.3045 (1) Å, c = 16.3367 (5) Å, α = 90°, β = 94.285 (3)°, γ = 90°, Z = 2 and V = 633.62 (3) Å3. Subsequently, the asymmetric unit of compound (NDMC) contains two molecules, while compound (NMMC) has single molecule. Strong intermolecular NH⋯O, and weaker CH⋯Cl and CH⋯S hydrogen bonds link the molecules of (NDMC) into dimers, enclosing R22(7) and R22(9) ring motifs. Intermolecular CH⋯S, bifurcated NH⋯O and CH⋯O hydrogen bonds, as well as CH⋯π interactions in (NMMC), attach molecules, enclosing R22(7) and R22(14) ring motifs. Furthermore, HS analysis explored, visualized, and quantified the significance of hydrogen bond contacts, and revealed active contributions for the packed crystals encompasses H…H 33.6 % for (NDMC), and 46.6 % for (NMMC), H…S/S…H 17.9 % for (NDMC), and 17.0 % for (NMMC), H…C/C…H 9.0 % for (NDMC), and 19.7 % for (NMMC), H…O/O…H 14.8 % for (NDMC), and 14.3 % for (NMMC), and H…Cl/Cl…H 17.8 % for (NMMC). Hydrogen bonding and van der Waals contacts strongly influence crystal packings of the crystallized compounds. Similarly, evaluation of energy frameworks (electrostatic, dispersion and total energies) indicated stabilization is strongly dominated by dispersion energy contribution in compound (NMMC). Finally, optimum molecular structures of both the compounds (NDMC and NMMC), were related with the experimental ones employing DFT at B3LYP/6–311G**(d,p) level. The most stable optimized conformation was geometrically complementary with the crystal structure. DFT computed frontier molecular energies and isodensities predicted these compounds to exhibit better electron pair acceptance nature than electron pair donor.

Qualitative and quantitative contributions of intermolecular interactions, quantum chemical calculation, biological activity and visible-light driven photo catalysts studies of nickel complex of 4-amino-N-(5-methyl-1,3,4-thiadiazol-2-yl)benzenesulfonamide

This study reports the successful synthesis and characterization of a nickel complex of the sulfamethizole (smtz) ligand. The complex was characterized using 1H NMR and FT-IR spectroscopic analyses. The synthesized complex exhibited promising properties as a biological and visible light-driven photocatalyst. Under visible light radiation, it displayed remarkable photo-degradation capabilities, achieving a degradation efficiency of 91.2% within 80 min against a solution of methylene blue (MB) with a concentration of 10 PPM in 100 mL. To understand the complex's biological response, viscosity measurements were conducted to investigate its mode of binding with CT-DNA. The results demonstrated that the nickel complex exhibited stronger inhibitory activity and lower cytotoxicity compared to the smtz ligand, as evidenced by cytotoxic analysis and minimum inhibitory concentration (MIC) data against a range of gram-positive and gram-negative pathogens. Furthermore, the crystal structure of the complex was determined through single-crystal X-ray diffraction analysis, revealing its crystallization in the triclinic space group P-1. The asymmetric part of the unit cell consisted of a Ni0.5 metal atom, one -Picoline solvent molecule, one smtz ligand, and one coordinated water molecule. To gain further insights into the complex's properties, Hirshfeld surfaces (HS) and a 3D energy framework approach were utilized to visualize its active and inactive surfaces. The analysis indicated that the dispersion energy contribution in molecular packing was significantly greater than that of electrostatic energy. Additionally, calculations of the HOMO-LUMO energy and other quantum chemical parameters were performed to understand the molecule's stability. Overall, the synthesized nickel complex of the sulfamethizole ligand exhibited remarkable photocatalytic properties, strong inhibitory activity against pathogens, and a stable crystal structure. These findings contribute to the understanding of the complex's potential applications in photocatalysis and biomedical research.

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.

Synthesis, Structural Investigations, DNA/BSA Interactions, Molecular Docking Studies, and Anticancer Activity of a New 1,4-Disubstituted 1,2,3-Triazole Derivative.

We report herein a new 1,2,3-triazole derivative, namely, 4-((1-(3,4-dichlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-hydroxybenzaldehyde, which was synthesized by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The structure of the compound was analyzed using Fourier transform infrared spectroscopy (FTIR), 1H NMR, 13C NMR, UV-vis, and elemental analyses. Moreover, X-ray crystallography studies demonstrated that the compound adapted a monoclinic crystal system with the P21/c space group. The dominant interactions formed in the crystal packing were found to be hydrogen bonding and van der Waals interactions according to Hirshfeld surface (HS) analysis. The volume of the crystal voids and the percentage of free spaces in the unit cell were calculated as 152.10 Å3 and 9.80%, respectively. The evaluation of energy frameworks showed that stabilization of the compound was dominated by dispersion energy contributions. Both in vitro and in silico investigations on the DNA/bovine serum albumin (BSA) binding activity of the compound showed that the CT-DNA binding activity of the compound was mediated via intercalation and BSA binding activity was mediated via both polar and hydrophobic interactions. The anticancer activity of the compound was also tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using human cell lines including MDA-MB-231, LNCaP, Caco-2, and HEK-293. The compound exhibited more cytotoxic activity than cisplatin and etoposide on Caco-2 cancer cell lines with an IC50 value of 16.63 ± 0.27 μM after 48 h. Annexin V suggests the induction of cell death by apoptosis. Compound 3 significantly increased the loss of mitochondrial membrane potential (MMP) levels in Caco-2 cells, and the reactive oxygen species (ROS) assay proved that compound 3 could induce apoptosis by ROS generation.

Accurate Evaluation of Dispersion Energies at Coupled Cluster Level to Understand the Substituent Effects in Am(III) and Eu(III) Complexes.

The effect of cyclic and aromatic substituents on the complexation behavior of phosphine oxide ligands with Am(III) and Eu(III) was investigated at density functional theory (DFT) and domain-based local pair natural orbital coupled-cluster (DLPNO-CC) levels. Combining DFT with accurate coupled cluster methods, we have evaluated the dispersion energy contributions to the complexation energies for trivalent Am and Eu complexes for the first time. Irrespective of the nature of substituents on the P atom, the electronic structure of the P═O group remains identical in all of the ligands. The study reveals the importance of dispersion interactions during complexation and is estimated to be more significant for Am(III) than for Eu(III) complexes.

Synthesis, Single Crystal XRD, In-Silico and In-Vitro Studies of Alkyl Substituted Acyl Thiourea as Carbonic Anhydrase Inhibitor

Carbonic anhydrases (CAs) representing the class of metalloenzymes are expressed widely and play a crucial role in various physiological and pathological processes. The Alkyl substituted Acyl Thiourea was synthesized and characterized by NMR spectroscopic technique. Single crystal X-ray diffraction was applied to determine the molecular and crystal structures. Synthesized compound crystallized in monoclinic system P 21/c space group. Intermolecular N–H···S hydrogen bonds and Intramolecular N–H···O hydrogen bond were found in crystal structure. H … H interactions have major contributions in crystal packing as depicted by Hirshfeld surface analysis. No large cavity was observed during void volume analysis in the crystal packing. Stabilization was dominated via the dispersion energy contributions in the synthesized compound. In Vitro analysis showed that synthesized compound inhibited the carbonic anhydrase activity to an appreciable extent. Quantum mechanical descriptors were calculated using DFT studies. In molecular docking, reactive parts of the synthesized molecule contributed in forming the hydrogen bond with receptor protein target. Finally, ADMET Analysis were performed to assess the drug-like behavior of synthesized compound. Carbonic Anhydrase enzyme inhibitor of pharmaceutical significance can be developed using the synthesized molecule ES-2 as a lead molecule.

Synthesis, Crystal Structure, Hirshfeld Surface Analysis, DNA/BSA Interaction and Molecular Docking Studies of 2-(6-(4-chlorophenyl)-1,2,4-triazin-3-yl)quinoline

We reported herein a new 1,2,4-triazine derivative, 2-(6-(4-chlorophenyl)-1,2,4-triazin-3-yl)quinoline, synthesized by cyclization of p‑chloro isonitrosophenylhydrazine with 2-quinolinecarboxaldehyde. Its structure was elucidated by FTIR, 1H NMR, 13C APT NMR, elemental analyses, and also its molecular and crystal structures were determined by single crystal X-ray analysis which revealed that the compound was crystallized in monoclinic system P 2/c space group with a = 17.2564 (6) Å, b = 6.0419 (3) Å, c = 14.4093 (5) Å, β = 103.469 (3)°, Z = 4 and V = 1461.01 (10) Å3. The Hirshfeld surface analysis of the crystal structure indicated that the most important contributions for the crystal packing were from H … H (29.2%), H … C/C … H (22.3%), H … N/CN … H (16.1%) and H … CI/CI … H (14.5%) interactions. Hydrogen bonding and van der Waals interactions were the dominant interactions in the crystal packing. The evaluation of the electrostatic, dispersion and total energy frameworks indicated that the stabilization was dominated via the dispersion energy contribution. The synthesized compound was investigated for CT-DNA and BSA binding activity using various in vitro and in silico techniques. Results were revealed that binding of the compound with CT-DNA via minor groove and with BSA via subdomain IIIB.

Synthesis, single crystal X-ray structure determination, Hirshfeld surface analysis, interaction energies, and density functional theory calculations of N,N'-(cyclohexane-1,4-dicarbonothioyl)bis(4-methylbenzamide)

The present research offers convenient synthesis, molecular and crystal structures of C2 symmetric N,N'-(cyclohexane-1,4-dicarbonothioyl)bis(4-methylbenzamide). The synthesized bis-amide crystallized in monoclinic crystal system, having space group of P 21/c with a = 17.8669 (14) Å, b = 6.3495 (5) Å, c = 9.6195 (7) Å, β = 101.567 (8)°, Z = 2 and V = 1069.13 (15) Å3. The asymmetric unit contains cyclohexane ring located on an inversion center, one dicarbonothioyl and one methylbenzamide group. In the crystal structure, the N–H···O, C–H···O and C–H···S hydrogen bonds link the molecules, enclosing R21(6), R22(16) and R22(22) ring motifs, into three-dimensional architecture. Hirshfeld surface (HS) analysis revealed the prevailing significance of hydrogen bond contacts. HS analysis suggested prominent contributions for crystal packing encompasses H…H (49.6%), H…C/C…H (18.9%) and H…S/S…H (16.0%). Hydrogen bonding and van der Waals contacts are the dominant interactions in the crystal packing. The respective volume of the crystal voids and the percentage of free spaces in the unit cell is calculated as 117.87 Å3 and 11.02% indicating the absence of any large cavity within the crystal and the associated stability of the crystal. Evaluation of the electrostatic, dispersion and total energy frameworks revealed that stabilization is dominated by dispersion energy contribution. Moreover, optimized molecular structure, using density functional theory at B3LYP/6-311G(d,p) level, were compared with the experimentally determined ones. HOMO–LUMO energy gap was determined, frequencies and molecular electrostatic potential surface were calculated at the B3LYP/6–311G level to predict sites for electrophilic and nucleophilic attacks. The significant charge polarity, half molecule spread of HOMO and LUMO impart bis-amide nucleophilic as well as electrophilic behavior with relative potency depending upon the nature of the attacking molecule.

Rationalization of supramolecular interactions of a newly synthesized binuclear Cu(II) complex derived from 4,4′,6,6′-tetramethyl 2,2′-bipyrimidine ligand through Hirshfeld surface analysis

A new binuclear copper (II) complex [Cu2L2Cl4(H2O)2] (1) derived from 4,4',6,6'-tetramethyl-2,2'-bipyrimidine (L) has been synthesized and characterized by the single crystal X-ray diffraction method. Single crystal analysis of complex 1 reveals that it crystallizes in the space group P21/n under a monoclinic system (β = 97.995(2)°, a = 7.6483(2), b = 7.2158(3) and c = 17.8477(6) Å). The ligand acts as a bis-bidentate one and each copper (II) center bears a square pyramidal geometry exploiting N2Cl2O chromophore. In the solid state, the complex is stabilized through classical O-H···Cl intermolecular hydrogen bonding incorporating coordinated water (as a solvent) and chloride ions and lone pair···π interactions. The Hirshfeld surface analysis demonstrates H···H/H···H, H···Cl/Cl···H, H···C/C···H, and C···Cl/Cl···C intermolecular interactions as the major contributor interactions in the solid-state packing of the molecular crystal. Interaction energy calculations carried out employing the wavefunction generated via B3LYP/6-31G(d,p) highlight the dominance of electrostatic energy and the contribution of polarization and dispersion energy towards the total energy of complex 1 in the solid state.

ANALYSIS OF THE CRYSTAL STRUCTURE AND ENERGY FRAMEWORKS OF 5-ACETIL-1,3-DIMETHYL BARBITURIC ACID

C8H9N2O4 was prepared via acetylation of 1,3-dimethyl barbituric acid. The atomic and crystalline structures were determined using single crystal analysis (X-ray). It is a member of the monoclinic system P 21/c group of space with a = 8.6056 (3) Å, b = 9.1602 (3) Å, c = 11.9601 (4) Å, β = 109.410 (3)°, Z = 4 and V = 889.22 (5) Å3. π–π interactions between circles of nearby molecules with intercentroid distances of 3.4300 (11) aid in the stability of the structure by keeping the crystals in place. The Hirshfeld surface (HS) analysis of the crystal structure reveals that the H... O/O... H (45.9%) and H... H (32.9%) interactions contribute the most to crystal packing. The most essential interactions in crystal packing are hydrogen bonding and van der Waals interactions. According to the dispersion, electrostatic and overall energy frameworks, the contribution of dispersion energy dominates the stability.

Green synthesis, X-ray crystallography, DFT and Hirshfeld analysis of C-2 symmetric 1,3-bis(4-ethylphenyl)triaz-1-ene

A green synthesis of the novel symmetrical title molecule 1,3-bis(4-ethylphenyl)triazene (3) was achieved by self-coupling of 4-ethylaniline at room temperature via diazotization under 4.5–5.0 pH in water in excellent yield and purity. The structure of 3 was inferred by spectroscopic data, elemental analysis and corroborated by single crystal X-ray crystallography. It crystallizes in monoclinic I 2/a space group. In crystal structure, the intermolecular N–H···N hydrogen bonds link the molecules into infinite chains along the b-axis direction in which they are highly effective in the stabilization of the structure. The Hirshfeld surface analysis confirms the importance of H-atom contacts in establishing the packing. The large number of H···H and H···C/C···H interactions suggest that van der Waals interactions and hydrogen bonding play the major roles in the crystal packing. The evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated via the dispersion energy contribution. The HOMO and LUMO energies are −0.19401 and −0.5546 respectively.

Crystal structure determination, Hirshfeld surface, crystal void, inter-molecular inter-action energy analyses, as well as DFT and energy framework calculations of 2-(4-oxo-4,5-di-hydro-1H-pyra-zolo[3,4-d]pyrimidin-1-yl)acetic acid.

In the title mol-ecule, C7H6N4O3, the bicyclic ring system is planar with the carb-oxy-methyl group inclined by 81.05 (5)° to this plane. In the crystal, corrugated layers parallel to (010) are generated by N-H⋯O, O-H⋯N and C-H⋯O hydrogen-bonding inter-actions. The layers are associated through C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯O/O⋯H (34.8%), H⋯N/N⋯H (19.3%) and H⋯H (18.1%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 176.30 Å3 and 10.94%, showing that there is no large cavity in the crystal packing. Computational methods revealed O-H⋯N, N-H⋯O and C-H⋯O hydrogen-bonding energies of 76.3, 55.2, 32.8 and 19.1 kJ mol-1, respectively. Evaluations of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via dispersion energy contributions. Moreover, the optimized mol-ecular structure, using density functional theory (DFT) at the B3LYP/6-311G(d,p) level, was compared with the experimentally determined one. The HOMO-LUMO energy gap was determined and the mol-ecular electrostatic potential (MEP) surface was calculated at the B3LYP/6-31G level to predict sites for electrophilic and nucleophilic attacks.

Crystal structure, Hirshfeld surface analysis, inter-action energy and DFT calculations and energy frameworks of methyl 6-chloro-1-methyl-2-oxo-1,2-di-hydro-quinoline-4-carboxyl-ate.

In the title compound, C12H10ClNO3, the di-hydro-quinoline moiety is not planar with a dihedral angle between the two ring planes of 1.61 (6)°. An intra-molecular C-H⋯O hydrogen bond helps to establish the rotational orientation of the carboxyl group. In the crystal, sheets of mol-ecules parallel to (10) are generated by C-H⋯O and C-H⋯Cl hydrogen bonds, and are stacked through slipped π-stacking inter-actions between inversion-related di-hydro-quinoline units. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (34.2%), H⋯O/O⋯H (19.9%), H⋯Cl/Cl⋯H (12.8%), H⋯C/C⋯H (10.3%) and C⋯C (9.7%) inter-actions. Computational chemistry indicates that in the crystal, the C-H⋯Cl hydrogen-bond energy is -37.4 kJ mol-1, while the C-H⋯O hydrogen-bond energies are -45.4 and -29.2 kJ mol-1. An evaluation of the electrostatic, dispersion and total energy frameworks revealed that the stabilization is dominated via the dispersion energy contribution. 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, and the HOMO-LUMO behaviour was elucidated to determine the energy gap.

Synthesis, structure determination, Hirshfeld surfaces analysis and anticancer activity study of a new biomolecule: (2E)-2-{[4-(benzyloxy)phenyl]methylidene}-3,4-dihydronaphthalen-1(2H)-one

A new chalcone derivative (2E)-2-{[4-(benzyloxy) phenyl]methylidene}-3,4-dihydronaphthalen-1(2H) was synthesized using Claisen-Schmidt condensation reaction and crystallized by slow evaporation method at ambient temperature. The structure of the title compound was determined by the single-crystal X-ray diffraction (XRD) technique. Hirshfeld surfaces mapped over the properties dnorm, electrostatic potential,shape index, curvedness, fragment patches, 2 D fingerprint plots, and the energy frameworks were generated and analyzed. The red spots on the dnorm surface indicate weak intermolecular interactions such as hydrogen bonds, π…π and C-H…π contacts. The C-H…π stacking is visualized as adjacent red and blue triangles in the shape index, and by flat regions in the curvedness property. From the 2 D fingerprint plots, the contribution to the total Hirshfeld surface due to the H…H contacts was found to be the highest with 51.7% followed by C···H/H···C (33.9%), and H···O/O···H(12.2%) contacts. The energy framework analysis reveals that the dispersion energy contribution is the most to the total energy than the other component energies. In-vitro and in-silico anti-proliferative activity of the prepared compound showed excellent anti-cancer activity on MCF-7 cell lines at a concentration of 15.6 µg/mL with 50.86% of cell viability. The molecular docking analysis showed the best binding affinity between the compound and the target protein.

Synthesis, crystal structure, crystal supramolecularity and Hirshfeld surface analysis of (E)-1-(2,5-dichlorothiophen-3-yl)-3-o-tolylprop-2-en-1-one

• Crystal and molecular structure of ( E )−1-(2,5-dichlorothiophen-3-yl)−3-o-tolylprop-2-en-1-one. • 3D framework structure. • C–H•••O and C–H•••Cl, Cl•••Cl and S•••Cl interactions and crystal packing. • Hirshfeld surface analysis. • Energy frameworks analysis. • Dispersion energy contributions are the most important in stabilizing the crystal structure. The asymmetric unit of, C 14 H 10 Cl 2 OS, I , consists of one independent molecule with E configuration about the C C bond. The molecular structure composed of two aromatic rings, the 2,5-dichlorothiophenyl and the tolyl that are linked by the central –CO—CH CH– unit. The molecule is planar as indicated by the dihedral angle [4.27°] between the aromatic rings. The molecular structure is stabilized by two C—H•••O and one C—H•••Cl intramolecular hydrogen bonds forming S (5) S (5) S (6) ring motifs. In the crystal, the molecules are connected by C—H•••O/Cl, Cl•••Cl and S•••Cl interactions into a 3-dimensional supramolecular array. The Hirshfeld surface analysis revealed that the most significant interactions are: H•••H (25.7%), Cl•••H/H•••Cl (15.6%), C•••H/H•••C (15.3%), O•••H/H•••O (9.9%), C•••C (9.5%), amongst others. The calculated interaction energies indicate that the dispersion energy contributions are the most important in stabilizing the crystal structure. Crystal and molecular structure of ( E )-1-(2,5-dichlorothiophen-3-yl)-3-o-tolylprop-2-en-1-one are reported. Hirshfeld surface analysis and energy framework simulations are discussed.

Isomeric nitro substituted symmetrical benzamides: Crystal Structures, Hirshfeld surface analysis, 3D energy frameworks, DNA binding and cell line studies

Isomeric nitro substituted symmetrical benzamides, 2-nitro-N-(2-nitrobenzoyl)benzamide – ASP4 and 3-nitro-N-(3-nitrobenzoyl)benzamide – ASP5, were synthesized. Analysis of both crystals approved the structures of synthesized compounds as assigned from spectroscopic data. The intermolecular N–H···O and C–H···O hydrogen bonds linked the molecules, through the bifurcated hydrogen bonds, into three-dimensional architectures, in which they may be effective in the stabilizations of the structures. π–π interactions between the benzene rings of neighboring molecules further consolidated the crystal packings. Crystal structures by Hirshfeld surface (HS) analysis specified the substantial contributions for the crystal packing that are from H ... O/O ... H (46.4%) and H ... H (20.3%) (ASP4) and H ... O/O ... H (36.7%), H ... C/C ... H (19.9%) and H ... H (14.1%) (ASP5) interactions. The N–H···O and C–H···O hydrogen bond energies, by computational analysis, were found to be 71.0 and 50.5 kJ mol−1 (for ASP4) and 37.0, 36.9 and 26.0, 24.1 kJ mol−1 (for ASP5). The evaluations of the electrostatic, dispersion and total energy frameworks indicated that the stabilizations were dominated via the dispersion energy contributions in both compounds. DNA binding studies pointed that ASP4 has comparatively stronger interaction with DNA. Glioblastoma cancer (U87) and human embryonic kidney (HEK-293) cell lines studies of both the compounds revealed their promising anticancer drug candidacy. However, ASP4 showed less toxicity towards normal cells, hence comparatively safer than ASP5.

Crystal structure, Hirshfeld surface analysis and energy framework study of 6-formyl-7,8,9,11-tetra-hydro-5H-pyrido[2,1-b]quinazolin-11-one.

At 100 K, the title compound, C13H12N2O2, crystallizes in the ortho-rhom-bic space group Pna21 with two very similar mol-ecules in the asymmetric unit. An intra-molecular N-H⋯O hydrogen bond leads to an S(6) graph-set motif in each of the mol-ecules. Inter-molecular π-π stacking and C=O⋯π inter-actions involving the aldehyde O atoms link mol-ecules into stacks parallel to [100]. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing stem from H⋯H (49.4%) and H⋯O/O⋯H (21.5%) inter-actions. Energy framework calculations reveal a significant contribution of dispersion energy. The crystal studied was refined as a two-component inversion twin.

Methyl 3-[(1-benzyl-4-phenyl-1H-1,2,3-triazol-5-yl)formamido]-propano-ate: crystal structure, Hirshfeld surface analysis and computational chemistry.

The title compound, C20H20N4O3, is constructed about a tri-substituted 1,2,3-triazole ring, with the substituent at one C atom flanked by the C and N atoms being a substituted amide group, and with the adjacent C and N atoms bearing phenyl and benzyl groups, respectively; the dihedral angle between the pendant phenyl rings is 81.17 (12)°, indicative of an almost orthogonal disposition. In the crystal, pairwise amide-N-H⋯O(carbon-yl) hydrogen bonds lead to a centrosymmetric dimer incorporating methyl-ene-C-H⋯π(benzene) inter-actions. The dimers are linked into a supra-molecular layer in the ab plane via methyl-ene-C-H⋯N(azo) and benzene-C-H⋯O(amide) inter-actions; the layers stack along the c-axis direction without directional inter-actions between them. The above-mentioned inter-molecular contacts are apparent in the analysis of the calculated Hirshfeld surface, which also provides evidence for short inter-layer H⋯C contacts with a significant dispersion energy contribution.

Measured and calculated O2-broadening coefficients of C2H4 in the 1800–2350 cm-1 spectral region

The goal of this study is to measure and calculate for the first time the O2-broadening coefficients of ethylene (C2H4) in the 5 µm region. High-resolution Fourier transform spectra were recorded at various pressures for the whole 1750–3000 cm-1 spectral range. Using these spectra, a large set of 590 O2-broadening coefficients was measured for the ν7 + ν8, ν4 + ν8, ν6 + ν10, ν6 + ν7, ν3 + ν10 and ν4 + ν6 bands. The broadening coefficients were measured using a mono-spectrum non-linear least squares fitting procedure of Voigt profiles which appeared to properly model the observed molecular line shapes within the noise level. These coefficients are compared to theoretical results calculated with the semi-classical Robert and Bonamy formalism in which the intermolecular potential includes electrostatic and dispersion energy contributions. These results are generally in satisfactory agreement with experimental data. The average discrepancy 〈((γmea−γcal)/γmea)×100〉 and the absolute difference 〈(|γmea−γcal|/γmea)×100〉 between the measured and calculated values for 590 lines are (−2.3 ± 8.9)% and (7.3 ± 5.5)%, respectively. The rotational and vibrational dependences of O2-broadening coefficients are examined. The present results of C2H4O2 and those of C2H4N2 are used to determine the corresponding C2H4-air system. Comparison between obtained results leads to an average value of the absolute difference of (7.2 ± 5.5)%.