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In this report, we have presented the theoretical investigation of anilinium hydrogen oxalate hemihydrate – an organic crystalline salt. The molecular geometry, as well as the vibrational parameter...

The crystals of N-acetylglycine were obtained by the slow evaporation of an aqueous solution at room temperature. Single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic system with centro symmetric space group P21/c with lattice parameters are a = 4.8410(10) Å, b = 11.512(2) Å, c = 9.810(2) Å, α = 90º, β = 97.02(3)º, γ = 90º and V = 542.61 (Å)3. Quantum chemical computations have been performed on the grown crystal with DFT-B3LYP/6-311++G(d,p) basis set. The theoretically obtained geometrical parameters and vibrational frequencies are in close agreement with experimental data. HOMO-LUMO energy gap and molecular electrostatic potential map has also been calculated. The static and dynamic polarizability and first hyperpolarizability both were calculated to comprehend the potential applications of N-acetylglycine in nonlinear optics. Hirshfeld surface analysis has been performed to study the inter and intra molecular interactions between the molecule. Thus in present study, the structure-property relationship of novel N-acetylglycine molecule is studied for future nonlinear optical applications through experimental and theoretical approach.

A novel nitrogen rich energetic salt 2,4-diamino-6-methyl-1,3,5-triazinium levulinate dihydrate (DMTLDH) has been grown by slow evaporation method at room temperature. The grown synthesized salt crystallizes in the centrosymmetric space group P21/n of monoclinic system. The intermolecular hydrogen bond N–H···N, N–H···O, C–H···O, O–H···O type interactions stabilizes the structure and leads to three dimensional network. In addition to that the crystal structure also possesses C–O···Cg interactions. Also, quantum chemical computational studies using DFT-B3LYP/6-311++G(d,p) and PBEPBE/6-31G(d,p) basis set is used to analyze the structural parameters and vibrational frequencies of grown crystal. Frontier molecular orbital analysis describes the charge transfer within the molecule and also other electronics parameters were calculated. The natural bonding orbital analysis has also been performed to study the stability of the molecule. Further, the crystal packing behaviour of DMTLDH was studied quantitatively with the aid of Hirshfeld surface analysis.

Pure Thiosemicarbazide 5-Sulfosalicylate crystals (T5SS) have been grown by slow evaporation technique. The various functional groups present in the crystal are confirmed by FT-IR spectral analysis. The Vickers microhardness test clearly shows that the grown crystal belongs to soft material category and obeys the reverse indentation size effect for the applied loads. Dielectric study shows that dielectric constant decreases with increase in frequency for the grown crystal. Thermogravimetric analysis reveals the thermal stability of the materials.

In the present work, both experimental and theoretical investigation on geometrical structure and vibrational frequencies of Thiosemicarbazide 5 Sulfosalicylate (T5SS) has been carried out. DFT -B3LYP/6–31++G(d,p) method has been chosen for the theoretical computations.. The optimised geometric bond length and bond angles of T5SS are compared with experimental values. The vibrational spectra obtained from DFT were interpreted and compared with experimentally recorded values. It is found that the scaled wavenumber values calculated from DFT are very close to the experimentally observed wavenumber. Thus the present study aimed to investigate the synergy between the experimental and theoretical data of crystal structure and vibrational spectra of Thiosemicarbazide 5 Sulfosalicylate (T5SS) crystal.

Aniline is the one of the most prominent materials used for the production of many industrial fields. Since, due to the broad application the review on aniline has attracted the attention of many researchers. It has a major role in many of the industrial sectors. It helps in providing the manufacturing of rubber and other products for the production of parts for the motors. It is the primary product in the field of industrial chemistry. It has increased its attention after the use of aniline as a byproduct in the synthesis of many chemicals. The hydrogen bonding between the acceptor and donor plays a vital role in the structural properties of the crystals. Therefore this review gives a broad review on aniline, its derivatives and their applications in various fields. It also touches on the importance of hydrogen bonding within the formation of crystals compared with the other interactions.

In the present communication, aniline with oxalic acid molecular complex (C6H5NH3+.C2HO4-.0.5H20) has been taken as the subject. The anilinium oxalate hemihydrate – a new crystalline product have been grown by slow evaporation technique at room temperature. Single crystal X-ray diffraction study reveals that the grown crystal crystallizes in monoclinic system with centro symmetric space group C2/c with primitives. a = 24.004(5)A, b = 5.7500(10)A, c = 13.890(3) A and interfacial angles α = γ = 90° and β = 109.29(3)o. The strong hydrogen bond interactions between the singly protonated anilinium cation and single dissociated oxalate (1-) anions forms a three dimensional network. The crystallite size is calculated to be 17.355 μm using Debye-Scherrer’s formula. Room temperature powder infrared and Raman measurements for the aniline oxalate molecular complex (1:1) were carried out. The FT-IR and FT Raman spectra have been recorded and various vibrations of aniline as well as oxalate ions present in the grown crystal is identified and discussed in detail. Further the 3D Hirshfeld surface analysis and 2D fingerprint maps gives deep insight into the intermolecular interactions between the compound.

Mechanical properties of some amino acid based derivatives plays a versatile role in the device fabrication due to its mechanical strength. One such acetyl derivative of glycine named N-acetylglycine has been taken in the present study for investigation. Hardness analysis has been carried out on the grown crystal with various loads and it was observed that Vicker’s hardness number (Hv) varied for different loads. The work hardening coefficient is calculated to be 1.628 which confirms that the grown crystal comes under moderately hard material category. Other mechanical parameters like minimum load indentation (W), materials constant (k1), load dependent constant (A1) and elastic stiffness constant (C11) have also been calculated. The thermal analysis has also been carried and it reveals that the complete weight loss of N-acetylglycine starts from 208.60 ºC and ends at 281.58 ºC. The corresponding DTA peak is observed at 217.97 ºC which is the melting point of the sample. As expected, there is no phase transition till the material melts and this enhances the temperature range for the utility of the crystal. Kinetic and thermodynamic parameters have been calculated. All the results obtained from hardness as well as thermal measurement confirm the material may be suitable for electro-optic device applications. Further, the 3D Hirshfeld surface analysis and 2D fingerprint maps gives deep insight into the intermolecular interactions between the compound.

An organic crystalline salt 2,4-diamino-6-methyl-1,3,5-triazinium trifluroacetate (DMTFA) has been imposed for experimental and theoretical investigation. Gaussian 09 program has been used to compute the quantum chemical theoretical calculations. DFT/B3LYP-6-311++G(d,p) approach is adapted to optimize the structure. Structural and vibrational studies have been carried out by this approach followed by the correlation of experimental and theoretical results. Natural bonding orbital analysis, molecular electrostatic potential and frontier molecular orbital investigations substantiates the charge transfer besides the presence of strong inter and intra molecular interactions. Apart from the three dimensional Hirshfeld surface analysis and two dimensional fingerprint maps provides profund vision about the intermolecular interactions between the molecules.

The single crystals of p-nitroanilinium p-toluene sulphonate have been grown by slow solvent evaporation method at room temperature. X-Ray diffraction data have been collected from single crystal X-ray diffraction analysis and reveals that the crystal crystallizes in monoclinic system with centro symmetric space group P 21/n. The lattice parameters are calculated to be a = 6.2189 (14)A, b = 30.7201 (36)A, c = 7.4080 (12) A, α = γ = 90° and β = 97.25 (3)o. The volume of the unit cell is calculated to be = 1404.0 (4) (A)3. The hydrogen bond interactions between the singly protonated 4-nitroanilinium cation and single dissociated toluene sulphonate (1-) anions forms a three dimensional network. The crystallite size is calculated to be 14.264 μm from powder X-ray diffraction spectrum by using Debye-Scherrer's formula. The vibrational spectra provide the presence of NH3, CH3, SO3 and NO2 group of the title molecule. Further the 3D Hirshfeld surface analysis and 2D fingerprint maps were used for quantitative mapping out of the intermolecular interactions.

The selenic hydrogen bonded salt Bis(5-amino-3-carboxy-1H-1,2,4-triazol-4-ium) selenate dihydrate (BACTSe) has been synthesized and characterized by XRD, FT-IR and FT-Raman techniques. It crystallizes in the C2/c space group and displays a three-dimensional framework stabilized mainly via intermolecular O H⋯O, N H ⋯O and O H⋯N hydrogen bonds. The quantum chemical study performed with ab initio UHF method using 6-311G(d,p) base set, has permitted the determination of the structural parameters, the total energy, the HOMO and LUMO energies, the thermodynamic parameters and the NBO charges. Moreover, normal mode frequencies and corresponding vibrational assignments have been examined.

The comprehensive elucidation of the crystal structure, vibrational and Hirshfeld surface analysis of new crystalline product anilinium malonate C6H5NH3 +. C3H3O4 – are presented in this communication. Single crystals of anilinium malonate have been grown by the method of slow evaporation at room temperature. Single crystal XRD study has been carried out to study the structural properties of the grown crystal and it reveals that the crystal crystallizes in the monoclinic system with centrosymmetric space group P2(1)/n. Room temperature powder infrared and Raman spectra of the aniline malonic acid molecular complex (1:1) were carried out. All the characteristic frequencies present in the crystal gives the notable vibrational effect. Hirshfeld surface analysis has been carried out to know the intercontact between the atoms in the structure of the grown crystal.

The theoretical and experimental vibrational studies for poly thiourea silver nitrate (2:1) complex using DFT method are performed on the basis of experimental data. During the geometry optimization process one equilibrium structure was found. The Mulliken charges, harmonic vibrational frequencies, Infrared and Raman intensities were calculated on the basis of quantum chemical density functional calculations using firefly (PC GAMESS) Version 7.1G. The clear - cut assignments of observed bands are performed on the basis of potential energy distribution (PED) analysis. Highest Occupied Molecular Orbital (HOMO) and the Lowest Occupied Molecular Orbital (LUMO) are obtained and graphically illustrated with minimum energy. The energy difference between HOMO and LUMO is analyzed. The other molecular properties like molecular electrostatic potential, Mulliken charges and thermodynamic properties of the title compound have also been calculated.

In this communication, Fuzzy logic scheme is applied to optimize the energy of the N-acetylglycine molecule along with the support of density functional theoretical results. The structure is optimized with DFT/B3LYP-6-31G(d,p) basis set using Gaussian 09 program. Inorder to identify the functional groups present in the studied molecule, the vibrational frequencies have been computed with the help of Density Functional Theory (DFT) computations. The best two torsional angles D1(H2O1C4O3) and D2(H9N8C10O11) of N-acetylglycine molecule that gives the global minimum is chosen for the fuzzy logic input and the results are compared with DFT results. Finally we believe that the fuzzy logic scheme gives reliable facts about the optimization of the structure of N-acetylglycine molecule with minimum energy in the light of density functional theory.

Glycinium oxalurate (GO) single crystals has been synthesized and grown by the slow solvent evaporation method at room temperature. Single crystal X-ray diffraction study confirms that GO crystal crystallizes in the monoclinic system with centrosymmetric space group P121/c1. The grown crystals are built up from single protonated glycinium residues and single dissociated oxalurate anions. A combination of ionic and donor-acceptor hydrogen-bond interactions linking together the glycine and oxaluric acid residues forms a three-dimensional network. Hydrogen bonded network present in the crystal gives notable vibrational effect. The molecular geometry, vibrational frequencies and intensity of the vibrational bands have been interpreted with the aid of structure optimization based on HF and density functional theory B3LYP methods with 6-311++G(d,p) basis set. Frontier molecular orbital energies and other related electronic properties are calculated. The natural bonding orbital (NBO) charges have been calculated and interpreted. The molecular electrostatic potential map has been constructed and discussed in detail.

The structural and various spectroscopic parameter were determined by using quantum mechanical calculation for Indole-3-carboxylic acid (I3CA) molecule by B3LYP/6–311++G (d, p) method in this work. The optimized geometrical parameters were compared with XRD data. The spectral studies I3CA molecule were adopted by FT-IR, FT-Raman recorded 4000–400 cm−1 and 3500–50 cm−1. The recorded and calculated wavenumber are found to be good agreement. The UV–Vis absorption spectrum was recorded in the range of 200–600 nm. The charge transfer in the molecule is deeply analyzed by using NBO approach. Intermolecular interaction of the 13CA molecule is analyzed using Hirshfeld surface and finger print analysis. The I3CA has been screened to anti-microbial activity and found to exhibit anti-bacterial effects. Molecular docking results suggest that I3CA may exhibit inhibitory activity against different cancer protein.

Thermal Decomposition Behaviour of Bis(4-Nitrophenol)-2,4,6-Triamino-1,3,5-Triazine Monohydrate N. Kanagathara, M.K. Marchewka and G. Anbalaganc,∗ School of Basic Sciences, Vel Tech University, Chennai-62, India Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 937, 50-950 Wroclaw 2, Poland Department of Nuclear Physics University of Madras Guindy Campus Chennai-600025