MEP Surface Research Articles

DFT and MD simulations and molecular docking of co-crystals of octafluoro-1,4-diiodobutane with phenazine and acridine

Co-crystals are of immense applications in crystal engineering and pharmaceutical chemistry. Co-crystals of octafluoro-1,4-diiodobutane with phenazine (PHEF) and acridine (ACRF) are investigated by DFT and MD simulations. It was characterized using quantum mechanical calculations for geometry and spectroscopic properties. Frontier orbital energies are used to predict the energy properties and model the possible charge transfer between the co-crystal constituents. The frontier molecular orbital analysis indicates chemical reactivity and bioactivity of the co-crystals. The MEP surface reveals the various reactive surfaces in the co-crystal system, which is very important in deciding various biological activities. The UV-Vis spectra show the possible electronic transitions of the molecules. Simulated electronic spectra using the TDDFT method with CAM-B3LYP functional was used to investigate the suitability of the co-crystals to be used in DSSC. Moreover, docking analysis proves that co-crystals can act as potential inhibitors and paves the way for developing effective drugs. Further MD simulations could identify the molecules binding energy and stability.

Computational Quantum Chemical Study, Drug-Likeness and In Silico Cytotoxicity Evaluation of Some Steroidal Anti-Inflammatory Drugs

This paper contains a theoretical study of ten Anti-inflammatory steroids (AIS) on the understanding of the relationship between the structure and activity of the drug, the pharmacokinetic parameters responsible for bioavailability and bioactivity and finally the toxicity evaluation. DFT calculations with B3LYP/6-31G (d, p) level have been used to analyze the electronic and geometric characteristics deduced for the stable structure of the compounds. Moreover, using the Frontier Molecular orbital (FMO) energies, MEP surface visualizations and the density-based descriptors such as chemical potential (µ), electronegativity (χ), hardness (η) and softness (σ), the chemical stability were determined. Furthermore, in silico, studies showed that Lipinski rules are applied, which means that these (AIS) are expected to have a high probability of good oral bioavailability. On the other side, the bioinformatic Osiris/Molinspiration analyses of the relative cytotoxicity of these derivatives are reported in comparison to Cortisol. In fact, it has been showed that almost of these compounds are non-toxics except for Mometasone that presents a great risk of tumorigenicity during reproduction with a slightly mutagenic structure due to the two chloride atoms. from all results obtained, we can conclude that fluticasone has the best physico-chemical properties which explains its high efficiency.
 Keywords: Anti-inflammatory steroids, DFT, Lipinski rules, Tumorigenicity.

Structural and femtosecond third-order nonlinear optical properties of electron donor – acceptor substituted chalcones: An experimental and computational approach

Structural and third-order nonlinear optical (NLO) properties of two D-π-A-π-A [ (2E)-3-(3-chlorophenyl)-1-(3-nitrophenyl)prop-2-en-1-one (3C3NC) and (2E)-3-(4-fluorophenyl)-1-(4-nitrophenyl)prop-2-en-1-one (FNC)] and one D-π-A-π-D [(2E)-1-(9-anthryl)-3-(4-fluorophenyl) prop-2-en-1-one (FANC)] type chalcone derivatives were investigated experimentally as well as theoretically. All the three chalcones are centrosymmetric (CS) and crystallized in P21/c space group. In crystal packing, all compounds exhibit C–H⋯O hydrogen bonds and π···π interactions. From UV–Vis–NIR absorption spectra, the cut-off wavelength and optical band gaps of the chalcones were evaluated. The thermal stability and the melting point of the chalcones were determined from the TGA/DTA techniques. The ultrafast third-order NLO properties of the three chalcones in solution (0.01 M) were evaluated by Z-scan technique using femtosecond (fs) pulses from Ti: Sapphire laser (∼150 fs, 80 MHz, 800 nm). Third-order nonlinear absorption (NLA) coefficient (β ∼ 10−9 cmW−1), nonlinear refraction (NLR) index (n2∼10−14 cm2W−1), susceptibility (χ(3) ∼ 10−12 esu) and molecular hyperpolarizability (γh ∼ 10−31 esu) were unambiguously determined. The chalcones satisfy the condition to observe reverse saturable absorption (RSA) mechanism (σex > σg). Further, the larger values of σex/σg (∼2–3) indicate that the chalcones would exhibit remarkable optical limiting property. The estimated optical limiting (OL) threshold values are in the order of μJ/cm2. Further, all the chalcones have satisfied the one-photon and two-photon figures of merit conditions (W > 1 and T < 1) for the optical switching applications. In addition to experimental findings, the optimized geometry, HOMO-LUMO energy gap, NLO parameters such as electronic dipole moment, polarizability, first and second hyperpolarizabilities of all the three chalcones were determined theoretically (DFT) for different wavelength at B3LYP/6-311 + G (d,p) basic set. The experimentally determined second-order susceptibilities (Z-scan technique) are reasonably in agreement with the computational values (TD-DFT). The MEP surface revealed that the 3C3NC, FNC and FANC molecules have some potential sites for electrophilic and nucleophilic attack. The experimental and computational NLO data clearly suggest that the nonlinearity of chalcone molecules greatly depends on the electron donor and acceptor strengths of the substituents. Further, all the chalcones are potential materials for optical limiting and optical switching applications.

New 1,3,4-thiadiazol derivatives: Synthesis, computational study and X-Ray

In this study, 4-hydroxyphenyl-3H-1,2,4-triazol-3-one derivatives (1a-d), cyanomethoxyphenyl-3-alkyl/aryl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-acetonitriles (2a-d) and bis amino-1,3,4-thiadiazol-5-alkyl/aryl-2,4-dihydro-3H-1,2,4-triazol-3-one (3a-d) were synthesized. The new compounds were characterized by elemental analyses, IR, 1H NMR, 13C NMR and mass spectral studies. The molecular structure of compound 2c was determined by X-ray diffraction. Vibrational data, 1H NMR and 13C NMR chemical shifts of compound 3 b were obtained by DFT/B3LYP/6–311++G(d,p) method and theoretical spectral data were compared with the experimental ones. Furthermore, Gauswiev 5.0 was used to visualize the results of the computation MEP surface for compound 3 b.

Charge-assisted hydrogen bond and nitrile⋯nitrile interaction directed supramolecular associations in Cu(ii) and Mn(ii) coordination complexes: anticancer, hematotoxicity and theoretical studies

Charge-assisted H-bonds and nitrile⋯nitrile interactions directed assemblies in Cu(ii) and Mn(ii) complexes have been analyzed by MEP surface and NCI plot index. Anticancer activities and hematotoxictiy have been investigated.

Spectroscopic, Hirshfeld surface, charge transfer excitation, condensed Fukui function and molecular docking investigations of 1-(3-Bromo-2-thienyl)-3-(4-butoxyphenyl)‑prop-2-en-1-one

Abstract The heterocyclic derivative of 1-(3-Bromo-2-thienyl)-3-(4-butoxyphenyl)‑prop-2-en-1-one (3B2T4B) has been synthesized by dissolving 2-Acetyl-3-bromothiophene in methanol and mixing with 4-butoxybenzaldehyde. Spectroscopic investigations have been performed experimentally and theoretically to obtain FT-IR and FT-Raman vibrational spectra. The theoretical vibrational studies were performed by the DFT technique. The UV–Vis absorption spectrum calculates the band gap energy (ΔE = 3.645 eV), maximum oscillator strength (f = 0.906 a.u), and λ max values (340.09 nm) using TD-DFT method. The stability of the molecule has been analyzed by hyper-conjugative and charge delocalization using NBO analysis. Furthermore, Condensed Fukui functions, MEP, HOMO-LUMO and Hirshfeld surface were calculated that explain the integral of overlapping of hole-electron distributions and chemical reactivity of the title molecule. Molecular docking studies suggest that the compound may exhibit inhibitory activity against Interleukin 1 antagonist inhibitor of proteins 1ILR & 1IRA that have minimum binding energy as −4.96 and −6.08 kcal/mol.

Synthesis, spectroscopic characterization, DFT computations, nonlinear optical profile and molecular docking study of a novel chalcone derivative

Abstract A novel chalcone derivative, (E)-1-(3-hydroxyphenyl)-3-(2,4,6-trimethoxyphenyl)prop-2-en-1-one (Tx), was synthesized and its spectroscopic characterization was done by using the experimental FT-IR, Laser-Raman, UV–Vis. and NMR spectroscopic techniques. To support experimental spectroscopic data, computational analyses were performed with DFT/B3LYP method at the 6-311G++(d,p) basis set. The assignments of fundamental vibrational modes were defined in terms of PED% by using VEDA4xx software. HOMO, LUMO and UV–Vis. Spectral analyses were used for determination of molecular electronic transitions. By considering the computed HOMO and LUMO energy values, some global reactivity descriptors were theoretically investigated. MEP surface mapping was used to determine the nucleophilic and electrophilic reactive sites within the compound Tx. Thermodynamic features of the compound were theoretically studied within gas phase. The static polarizabilities and first order hyperpolarizabilities were used to investigate non-linear optical (NLO) profile of the compound. The protein-ligand interactions for the compound Tx docked into a breast cancer resistance protein ATP-binding cassette sub-family G member 2 (PDB ID: 6FFC ) were investigated with the molecular docking analysis.

Theoretical and experimental investigations of complexation with BF3.Et2O effects on electronic structures, energies and photophysical properties of Anil and tetraphenyl (hydroxyl) imidazol

The novel compounds (E)‐2‐(((4‐hydroxyphenyl)imino)methyl)phenol, Tetraphenyl (hydroxyl) imidazole and their corresponding Boron difluoride complexes were synthesized and characterized by spectroscopic techniques. Density functional theory calculations at B3LYP‐D3/6–311++G (d, p) level of theory were performed for the geometric parameters. The MEP surface studies were used to understand the behavior of molecules in terms of charge transfer and to determine how these molecules interact. We used the GIAO and the B3LYP‐D3 with a 6–311++ G (d, p) basis set to simulate the (1H‐NMR and 19F‐NMR) and the IR spectra, respectively. The corresponding calculated results are in good agreement with the experimental data. The stability of the molecule arising from hyperconjugation interaction and charge delocalization were analyzed using NBO analysis. FMOs revealed the occurrence of charge transfer within the molecule. The complexation using BF3.Et2O was also found to have remarkable effects on the electrochemical properties of the studied molecules, where (b) and (d) present lower chemical stability, higher reactivity and higher polarizability than (a) and (c), respectively. Moreover, the energy gap of (a) and (c) decreased after complexation using BF3.Et2O, indicating the reliability of the electrochemical evaluation of LUMO and HOMO energy levels. These values are the factors explaining the possible charge transfer interaction within the molecule. The absorption and emission spectra of the model compound were also simulated and compared to experimental observations in the DMF solvent. The results of DFT calculations supported the structural and spectroscopic data and confirmed the structure modification of frontier molecular orbitals for BF2 complexes as well as tunable potentials and energy levels.

Vibrational spectroscopic characterization, electronic absorption, optical nonlinearity computation and terahertz investigation of (2E) 3-(4-ethoxyphenyl)-1-(3-bromophenyl) prop-2-en-1-one for NLO device fabrication

The present study spotlights the key structure-property features of a chalcone derivative (2E) 3-(4-ethoxyphenyl)-1-(3-bromophenyl) prop-2-en-1-one (E3BC) for future applications in nonlinear optical devices through dual approach involving experimental and theoretical techniques. The sample has been characterized by 1H NMR, FT-IR, FT-Raman and terahertz spectroscopies. The experimental results are supported by computational studies using density functional theory. To analyse the 1H NMR spectra, theoretical calculations on chemical shifts were done by GIAO method. Complete vibrational assignments of the vibrational modes have been made on the basis of the potential energy distribution in terms of internal coordinates. The low frequency vibrational modes between 0.2 and 1.8 THz were examined via terahertz time domain spectroscopy. The UV–vis spectrum was recorded in methanol solution. The energies, absorption wavelengths and oscillator strengths of electronic singlet-singlet transitions were determined by time dependent density functional theory. The calculated HOMO-LUMO energy gap is small which reveals that the charge transfer takes place within the molecule and it can be exploited for the nonlinear optical applications. Information about the charge density distribution and the sites of chemical reactivity of the molecule has been obtained by mapping electron density with molecular electrostatic potential. The MEP surface around the bromine atom exhibited the dual nature. Along the C-Br axis the positive electrostatic potential (the σ-hole) is present while the remainder of the surface is negative. Hence bromine atom can interact electrostatically with both nucleophiles and electrophiles. For other atoms no atom-specific effects are found. The stability of the molecule arising from hyper conjugative interactions and charge delocalization has been interpreted using natural bond orbital analysis. The study indicates that the intramolecular charge transfer (n → σ∗, n → π∗ and π → π∗) can induce nonlinearity in the molecule and validates E3BC's candidature to be used as a nonlinear optical active material. In order to understand the nonlinear optical activity of the molecule the calculations of electronic dipole moment, polarizability, anisotropy of polarizability as well as first and second hyperpolarizabilities are performed using finite field approach implemented in the DFT method. The findings suggested that the first order hyperpolarizability of titled molecule is 139 times greater than the value of urea. The high value of first order hyperpolarizability shows that E3BC can be a potential candidate in the nonlinear optical applications. The vibrational contribution to the above properties has also been computed using the self-consistent field wave functions within the double harmonic oscillator approximation.

A DFT approach for theoretical and experimental study of structure, electronic, Hirshfeld surface and spectroscopic properties of 12-(4-bromophenyl)-2-(prop-2-ynyloxy)-9,10-dihydro-8H-benzo[a]xanthen-11(12H)-on single crystal

Xanthene-propargyl derivative was synthesized by multicomponent reaction and was characterized by SCXRD analysis. Structure was optimized to ground state using DFT calculations at the B3LYP/6-311++G(d, p) level of theory in gas phase and in solvent. NBO analysis was performed at same level of theory. The vibrational spectrum was obtained theoretically by DFT calculations; vibrational assignments were made to different vibrational modes using potential energy distribution (PED) method. The non-covalent interactions present in molecule were investigated with Hirshfeld surface and fingerprint plots analysis, shape index, and curvedness using SCXRD data while theoretically these interactions were investigated using reduced density gradient (RDG) method. MEP surface was also analyzed and chemical reactivity descriptors were calculated theoretically. FMO and TDOS analysis was performed to study energy and distribution of molecular orbitals. NLO analysis was performed to determine its ability to act as potential NLO material. The high value of molar refractivity was also calculated theoretically.

Magnetoelectropolishing treatment for improving the oxidation resistance of 316L stainless steel in pressurized water reactor primary water

The surfaces of 316L stainless steel with mechanical polishing (MP) or electropolishing (EP) in the presence of a magnetic field (MEP) before and after exposure to simulated pressurized water reactor (PWR) primary water were characterized by various techniques such as SEM, Raman spectroscopy, XPS and TEM measurements. The surface microhardness was lower and the surface roughness was higher for the as-treated MEP specimen than for the as-treated MP specimen. The oxide films that formed on the as-treated MP and MEP surfaces were nanometer-thick and rich in chromium. The Cr/(Fe + Ni) ratio of the as-treated MEP surface film was higher than that of the as-treated MP surface film. After exposure to simulated PWR primary water at 310 °C for 1050 h, a dark double oxide layer that was approximately 662 nm thick formed on the MP surface, while the MEP surface retained its original brightness as before exposure with a nanometer-thick oxide layer with a high Cr content. The MP and MEP specimens showed different oxidation kinetics when exposed to high temperature water. The high Cr/(Fe + Ni) ratio of the surface film on the MEP 316L SS contributed to its excellent oxidation resistance in simulated PWR primary water.

Crystal structure, spectroscopic characterization, DFT computations and molecular docking study of a synthesized Zn(II) complex

The Zn(II) complex, dichloro[N-hydroxy-1,1-di(2-pyridinyl)methanimine]zinc(II), was synthesized from the reaction between ZnCl2 and di-2-pyridylketone oxime. The structural and spectral characterizations were performed by using single crystal X-ray diffraction, FT-IR, Laser-Raman, NMR and UV–Vis spectroscopic techniques. To support experimental evidences, computational results were obtained with the DFT/B3LYP method using the 6-311++G(d,p)+LanL2DZ mixed basis set. Theoretical analyses of some structural and spectroscopic results of effects of intermolecular Cl···H interactions in the crystal packing of the Zn(II) complex were investigated with the mentioned computational level. The non-bonding interactions in the experimental crystal packing of the complex were examined by Hirshfeld surface analysis. The HOMO and LUMO analyses were used for investigation of electronic transitions obtained with UV–Vis spectroscopy. NBO analyses were used to investigate the hyperconjugation interactions between donor and acceptor groups, coordination environment, electronic configuration and electron numbers of the Zn(II) metal ion and the natural atomic charges of the complex. The nucleophilic and electrophilic reactive sites of the complex were studied by MEP surface analysis. The static polarizabilities (α) and static hyperpolarizabilities (β) were analyzed theoretically to characterize NLO profile of the complex. The interaction with A-DNA (PDB ID: 1ZF6) of the Zn(II) complex was investigated with a molecular docking study.

Structural, Spectroscopic, Electronic and Molecular Docking Studies on (11R,12 S)‐16‐Aminotetracyclo[6.6.2.02,7.09,14]hexadeca‐2(7),3,5,9(14),10,12‐hexaen‐15‐ol

AbstractMolecular structure analysis, vibrational and electronic spectroscopic studies and thermochemical features of (11R,12 S)‐16‐aminotetracyclo[6.6.2.02,7.09,14]hexadeca‐2(7),3,5,9(14),10,12‐hexaen‐15‐ol were investigated via both theoretical and experimental techniques. Experimental investigations were made by using FT‐IR, Raman, 1H and 13C NMR and UV‐Vis. spectroscopies. To support experimental evidences, molecular electronic structure computations were obtained with the DFT/B3LYP method at the 6–311G++(3d,3p) basis set. 2D and 3D Hirshfeld surfaces studies were performed to understand non‐bonding intermolecular interactions in solid phase crystal packing of the compound. MEP surface analysis was performed to investigate nucleophilic and electrophilic reactive sites of the compound. The highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMO) analyses were theoretically used for determination of electronic transitions corresponding to UV‐Vis. electronic absorption wavelengths. Enzyme‐ligand interactions between the compound with BACE1 (Beta‐Secretase1) inhibitor were determined via molecular docking study.

Hydrophobic pocket docking, double-proton prototropic tautomerism in contradiction to single-proton transfer in thione ⇔thiol Schiff base with triazole-thione moiety: Green synthesis, XRD and DFT-analysis

In the present study, an eco-friendly and efficient microwave-assisted synthesis of the (E)-4-((3,4-difluorobenzylidene)amino)-2,4-dihydro-5-methyl-3H-1,2,4-triazole-3-thione Schiff base ligand was described. XRD-single crystal analysis reflected the molecule occurs in an exo-thione tautomeric form in solid state. Therefore, gaseous-phase prototropic thione thiol tautomerism occurrence probability via single-proton intramigration and push/pull protons self-assemble double proton transfer exchange was DFT-computed. The newly designed thione-tautomer was well-characterized by MS, FT-IR, CHN-EA, 19F, 1H, 13C NMR, and XRD analysis. High degree of matching was recorded by comparing the experiment XRD exo-thione-tautomer structure parameters by their relatives DFT-optimized parameters. Moreover, the computed MEP and HSA surface interactions were compared to H-bonds and π-π stack interactions obtained by XRD-packing analyses. Docking studies reflected the compound as DNA strong hydrophobic pocket binder.

Structural and vibrational characteristics and vibronic coupling of tetramethyltetraselenafulvalene

The molecular, electronic and crystal structures of tetramethyltetraselenafulvalene (TMTSF) have been investigated. The experimental IR and Raman spectra and single crystal XRD for TMTSF have been interpreted. In order to facilitate this, computations have been carried out for the molecular structures and vibrational characteristics of the TMTSF molecule. Study of Molecular electrostatic potential surface of the TMTSF and its cation is also done. Normal mode assignments have been made on the basis of the computed potential energy distributions (PEDs). In addition, a comprehensive study of molecular geometries, atomic charges and vibrational fundamentals of TMTSF and its cationic molecule has been carried out. Vibronic coupling constants in TMTSF and TMTSF+ have been computed using the DFT/B3LYP results. The TMTSF molecule belongs to C2v point group symmetry. All the studied molecules exhibit partial double bond character as all the bond lengths are changed from their usual bond lengths. The partial double bond character has been found to be indicate that the conducting behaviour of these molecules. In the unit cell of TMTSF, some H atoms and all the Se atoms are interacting with the molecules of neighboring and its own cell. The major changes in frequencies from neutral to the cationic state for í (ring) and í(CC) are found for the both molecules. The vibronic coupling corresponding to a vibrational mode helps to transport charge along the stacks of a conducting organic molecules from a neutral molecule to an adjacent charged ion. The magnitude of the VCC is noticed to be maximum for the í (CC). The geometry of the neutral molecule under this mode resembles to that of the ion and vice-versa. The large VCC of this mode shows that removal of an electron is much easier during the vibrational modes. Thus from the present study i.e. the molecular, electronic and crystal structures and vibronic investigations confirm the conducting behaviour of the TMTSF molecule. From the MEP surface it is clear that the sites close to selenium atoms in TMTSF show region of most negative electrostatic potential.

DFT study including NBO, NLO response and reactivity descriptor of bis and tris (1,3-dithiole) tetrathiafulvalene

We present a density functional theory (DFT) study on the reactivity of bis and tris (1,3-dithiole) TTF 1-4 by using B3LYP/6-31G (d,p) level. The possible electrophile and nucleophile attacking sites of the title compounds is identified using MEP surface plot study. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gaps were calculated to explain the frontier molecular orbitals and to predict the quantum chemical descriptors. Local reactivity properties have been investigated using average local ionization energies and Fukui functions. Natural Bond Orbital analysis was computed and possible transitions were correlated with the electronic transitions. The calculated first hyperpolarizability (β 0 ) of bis and tris (1,3-dithiole) TTF molecules, indicates that investigated molecules might have not the NLO applications. Keywords: tetrathiafulvalenes; density functional theory; computational chemistry; quantum chemical calculations.

Theoretical investigations of ZnO/CdO material – A DFT approach

The theoretical investigations of ZnO/CdO material were carried out by using ab initio calculations. The bond parameters such as bond lengths, bond angles and dihedral angles were calculated at DFT/B3LYP/LANL2DZ level of theory. The NLO property of the title molecule was calculated using a first order hyperpolarizability calculation. NBO study reveals that the hyperconjucative interactions between the material. Homo-Lumo analysis the charge transfer occurs within the molecule. MEP surface predicts the reactive sites of the present molecule. In addition of Mulliken atomic charges and thermodynamic parameters were also plotted and calculated.

Supramolecular features of 2-(chlorophenyl)-3-[(chlorobenzylidene)-amino]-2,3-dihydroquinazolin-4(1H)-ones: A combined experimental and computational study

The molecular structures of two isomeric 2-(chlorophenyl)-3-[(chlorobenzylidene)-amino] substituted 2,3-dihydroquinazolin-4(1H)-ones have been determined via single crystal XRD. Both isomers contain chloro substitutions on each of the phenyl rings and as a result a broad spectrum of halogen mediated weak interactions are viable in their crystal structures. The crystal packing of these compounds is stabilized by strong N−H⋯O hydrogen bond and various weak, non-classical hydrogen bonds acting synergistically. Both the molecules contain a chiral center and the weak interactions observed in them are either chiral self-discriminatory or chiral self-recognizing in nature. The weak interactions and spectral features of the compounds have been studied through experimental as well as computational methods including DFT, MEP, NBO and Hiresfeld surface analyses. In addition, the effect of different weak interactions to dictate either chiral self-recognition or self-discrimination in crystal packing has been elucidated.

Structure-activity relationship of the ionic cocrystal: 5-amino-2-naphthalene sulfonate·ammonium ions for pharmaceutical applications

The ionic cocrystals of 5-amino-2-naphthalene sulfonate · ammonium ions (ANSA-⋅NH4+) were grown under slow evaporation method and examined in detail for pharmaceutical applications. The crystal structure and intermolecular interactions were studied from the single X-ray diffraction analysis and the Hirshfeld surfaces. The 2D fingerprint plots displayed the inter-contacts possible in the ionic crystal. Computational DFT method was established to determine the structural, physical and chemical properties. The molecular geometries obtained from the X-ray studies were compared with the optimized geometrical parameters calculated using DFT/6-31 + G(d,p) method. The band gap energy calculated from the UV–Visible spectral analysis and the HOMO-LUMO energy gap are compared. The theoretical UV–Visible calculations helped in determining the type of electronic transition taking place in the title molecule. The maximum absorption bands and transitions involved in the molecule represented the drug reaction possible. Non-linear optical properties were characterized from SHG efficiency measurements experimentally and the NLO parameters are also calculated from the optimized structure. The reactive sites within the molecule are detailed from the MEP surface maps. The molecular docking studies evident the structure-activity of the ionic cocrystal for anti-cancer drug property.

Synthesis, characterization, crystal structure and theoretical studies of 4-[(E)-(3-chloro-4-hydroxyphenyl) diazenyl]-1, 5-dimethyl-2-phenyl-1, 2-dihydro-3H-pyrazol-3-one

Crystals of new heterocyclic azo compound of 4-aminoantipyrine, 4-[(E)-(3-chloro-4-hydroxyphenyl)diazenyl]-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one have been grown by slow evaporation method at room temperature and its structural characterization was performed by X- ray diffraction method. The spectroscopic characterization was also performed by FT-IR, UV–Vis, 13C and 1H NMR techniques. The compound crystallizes in the monoclinic CC space group with cell dimensions a = 12.4842 (13), b = 16.4492 (16), c = 8.3389 (8) and β = 102.698 (3)°. The phenyl ring attached to the pyrazolone moiety is disordered over two positions with an occupancy ratio 52:48. The components of the disorder were refined. DFT calculations have been performed by using B3LYP/6-311G (d,p) level basis set. The calculated vibrational frequency showed a red shift for CO and OH stretching. The natural bond orbital analysis of monomer, dimer and trimer structures reveals the absence of intramolecular hydrogen bonding; however intermolecular hydrogen bonding is observed. The cationic and anionic reactive sites of compound have been visualized on MEP surface.