Displaying publications 1 - 20 of 34 in total

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  1. Jeevaraj M, Sivajeyanthi P, Edison B, Thanigaimani K, Balasubramani K, Razak IA
    Acta Crystallogr E Crystallogr Commun, 2017 Oct 01;73(Pt 10):1595-1598.
    PMID: 29250389 DOI: 10.1107/S2056989017013950
    In the title mol-ecular salt, 2C6H10N3O+·C8H4O42-, the N atom of each of the two 2-amino-4-meth-oxy-6-methyl-pyrimidine mol-ecules lying between the amine and methyl groups has been protonated. The dihedral angles between the pyrimidine rings of the cations and the benzene ring of the succinate dianion are 5.04 (8) and 7.95 (8)°. Each of the cations is linked to the anion through a pair of N-H⋯O(carboxyl-ate) hydrogen bonds, forming cyclic R22(8) ring motifs which are then linked through inversion-related N-H⋯O hydrogen bonds, giving a central R24(8) motif. Peripheral amine N-H⋯O hydrogen-bonding inter-actions on either side of the succinate anion, also through centrosymmetric R22(8) extensions, form one-dimensional ribbons extending along [211]. The crystal structure also features π-π stacking inter-actions between the aromatic rings of the pyrimidine cations [minimum ring centroid separation = 3.6337 (9) Å]. The inter-molecular inter-actions were also investigated using Hirshfeld surface studies and two-dimensional fingerprint images.
  2. Jeevaraj M, Sivajeyanthi P, Edison B, Thanigaimani K, Balasubramani K, Razak IA
    Acta Crystallogr E Crystallogr Commun, 2017 Sep 01;73(Pt 9):1305-1307.
    PMID: 28932461 DOI: 10.1107/S2056989017011252
    In the title mol-ecular salt, C6H10N3O(+)·C7H5O3(-), the cation is protonated at the N atom lying between the amine and methyl substituents and the dihedral angle between the carboxyl group and its attached ring in the anion is 4.0 (2)°. The anion features an intra-molecular O-H⋯O hydrogen bond, which closes an S(6) ring. The cation and anion are linked by two N-H⋯O hydrogen bonds [R2(2)(8) motif] to generate an ion pair in which the dihedral angle between the aromatic rings is 8.34 (9)°. Crystal symmetry relates two ion pairs bridged by further N-H⋯O hydrogen bonds into a tetra-meric DDAA array. The tetra-mers are linked by pairs of C-H⋯O hydrogen bonds to generate [100] chains. Hirshfeld surface and fingerprint plot analyses are presented.
  3. Thanigaimani K, Arshad S, Khalib NC, Razak IA, Arunagiri C, Subashini A, et al.
    PMID: 25942090 DOI: 10.1016/j.saa.2015.04.028
    The structure of (E)-1-(4-Bromophenyl)-3-(napthalen-2-yl)prop-2-en-1-one (C19H13BrO) crystallized in the triclinic system of P-1 space group. The unit cell dimensions are: a=5.8944 (9)Å, b=7.8190 (12)Å, c=16.320 (2)Å, α=102.4364 (19)°, β=95.943 (2)°, γ=96.274 (2)° and Z=2. The physical properties of this compound was determined by the spectroscopic methods (FTIR and (1)H and (13)C NMR). Quantum chemical investigations have been employed to investigate the structural and spectral properties. The molecular structure, vibrational assignments, (1)H and (13)C NMR chemical shift values, non-linear optical (NLO) effect, HOMO-LUMO analysis and natural bonding orbital (NBO) analysis were calculated using HF and DFT/B3LYP methods with 6-311++G(d,p) basis set in the ground state. The results show that the theoretical calculation of the geometrical parameters, vibrational frequencies and chemical shifts are comparable with the experimental data. The crystal structure is influenced and stabilized by weak C-H⋯π interactions connecting the molecules into infinite supramolecular one dimensional ladder-like arrangement. Additionally, this compound is evaluated for their antibacterial activities against gram positive and gram negative strains using a micro dilution procedure and shows activities against a panel of microorganisms.
  4. Sivajeyanthi P, Balasubramani K, Jeevaraj M, Thanigaimani K, Khalib NC, Razak IA
    Acta Crystallogr E Crystallogr Commun, 2015 Jun 01;71(Pt 6):o376-7.
    PMID: 26090174 DOI: 10.1107/S2056989015008397
    In the crystal of the title mol-ecular salt, C7H9N6O(+)·NO3 (-), the cations and anions are linked via N-H⋯O and O-H⋯O hydrogen bonds, forming sheets parallel to (100). Within the sheets there are numerous hydrogen-bonding ring motifs.
  5. Arunagiri C, Subashini A, Saranya M, Thomas Muthiah P, Thanigaimani K, Abdul Razak I
    PMID: 25084236 DOI: 10.1016/j.saa.2014.07.016
    The molecular structure of a new Schiff base, 2-[4-hydroxy benzylidene]-amino naphthalene (HBAN) has been examined by HF and B3LYP/6-311++G(d,p) calculations. The X-ray structure was determined in order to establish the conformation of the molecule. The compound, C17H13NO, crystallizes in the orthorhombic, P212121 space group with the cell dimension, a=6.2867(2), b=10.2108(3), c=19.2950(6) Å, α=β=γ=90° and z=4. The asymmetric unit contains a molecule of a Schiff base. A strong intermolecular O-H⋯N and a weak C-H⋯O hydrogen bonds stabilized the crystal structure. The vibrational spectra of HBAN have been calculated using density functional theoretical computation and compared with the experimental. The study is extended to the HOMO-LUMO analysis to calculate the energy gap (Δ), Ionization potential (I), Electron Affinity (A), Global Hardness (η), Chemical Potential (μ) and Global Electrophilicity (w). The calculated HOMO and LUMO energy reveals that the charge transfer occurs within the molecule.
  6. Edison B, Balasubramani K, Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2014 Aug 1;70(Pt 8):o857-8.
    PMID: 25249908 DOI: 10.1107/S1600536814015220
    In the title mol-ecular salt, C4H6ClN4 (+)·C5H7O4 (-), the cation is essentially planar, with a maximum deviation of 0.037 (1) Å for all non-H atoms. The anions are self-assembled through O-H⋯O hydrogen bonds, forming a supra-molecular zigzag chain with graph-set notation C(8). In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds with an R 2 (2)(8) ring motif. This motif further self-organizes through N-H⋯O and O-H⋯O hydrogen bonds, generating an array of six hydrogen bonds, the rings having graph-set notation R 3 (2)(8), R 2 (2)(8), R 4 (2)(8), R 2 (2)(8) and R 3 (2)(8). In addition, another type of R 2 (2)(8) motif is formed by inversion-related pyrimidinium cations via N-H⋯N hydrogen bonds, forming a two-dimensional network parallel to (101).
  7. Purushothaman M, Thanigaimani K, Arshad S, Silambarasan S, Razak IA, Ali KM
    Acta Crystallogr Sect E Struct Rep Online, 2014 Jul 1;70(Pt 7):o812-3.
    PMID: 25161592 DOI: 10.1107/S1600536814014354
    In the title compound, C14H12ClN5, the di-hydro-pyridine ring adopts a shallow boat conformation. The dihedral angle between the plane of this ring and that of the chloro-benzene ring is 69.15 (15)°. In the crystal, mol-ecules are linked by N-H⋯N and N-H⋯Cl hydrogen bonds, generating (001) sheets.
  8. Dhanabalan N, Thanigaimani K, Arshad S, Razak IA, Santhanaraj KJ
    Acta Crystallogr Sect E Struct Rep Online, 2014 Jun 1;70(Pt 6):o657-8.
    PMID: 24940241 DOI: 10.1107/S160053681401023X
    The asymmetric unit of the title hydrated salt, C13H11N2 (+)·C7H6NO2 (-)·2H2O, consists of two independent 9-amino-acridinium cations, two 4-amino-benzoate anions and four water mol-ecules. Both 9-amino-acridinium cations are essentially planar, with maximum deviations of 0.034 (1) and 0.025 (2) Å, and are protonated at the pyridine N atoms. The 4-amino-benzoate anions are approximately planar, with dihedral angles of 9.16 (19) and 5.4 (2)° between the benzene ring and the carboxyl-ate group. In the crystal, the two independent anions are connected by N-H⋯O hydrogen bonds, forming a layer parallel to (100). The layers are connected through the cations by N-H⋯N and N-H⋯O hydrogen bonds. The water mol-ecules, which form O-H⋯O hydrogen-bonded chains along the b-axis direction, connect the anions and the cations by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds. The crystal structure also features π-π inter-actions [centroid-centroid distances = 3.6343 (9)-3.8366 (10) Å] and a C-H⋯π inter-action.
  9. Thanigaimani K, Arshad S, Razak IA, Makeshvaran D, Balasubramani K
    PMID: 23795126 DOI: 10.1107/S1600536813013895
    The 4-methyl-benzoic acid mol-ecule of the title adduct, C10H11N5·C8H8O2, is approximately planar with a dihedral angle of 6.3 (2)° between the carb-oxy-lic acid group and the benzene ring. In the triazine mol-ecule, the plane of the triazine ring makes a dihedral angle of 29.2 (2)° with that of the adjacent benzene ring. In the crystal, the acid and base mol-ecules are linked via N-H⋯O and O-H⋯N hydrogen bonds with an R 2 (2)(8) motif, and the acid-base pairs are further connected via N-H⋯N hydrogen bonds with R 2 (2)(8) motifs, forming a supra-molecular ribbon along [101]. Between the tapes, a weak C-H⋯π inter-action is observed.
  10. Thanigaimani K, Khalib NC, Razak IA, Lavanya P, Balasubramani K
    Acta Crystallogr Sect E Struct Rep Online, 2013 Jun 01;69(Pt 6):o968-9.
    PMID: 23795125 DOI: 10.1107/S1600536813013883
    The benzoic acid mol-ecule of the title adduct, C10H11N5·C7H6O2, is approximately planar, with a dihedral angle of 7.2 (3)° between the carb-oxy-lic acid group and the benzene ring. In the triazine mol-ecule, the plane of the triazine ring makes a dihedral angle of 28.85 (9)° with that of the adjacent benzene ring. In the crystal, the two components are linked by N-H⋯O and O-H⋯N hydrogen bonds with an R 2 (2)(8) motif, thus generating a 1 + 1 unit of triazine and benzoic acid mol-ecules. The acid-base units are further connected by N-H⋯N hydrogen bonds with R 2 (2)(8) motifs, forming a supra-molecular ribbon along [101]. The crystal structure also features weak π-π [centroid-centroid distances = 3.7638 (12) and 3.6008 (12) Å] and C-H⋯π inter-actions.
  11. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Apr 1;69(Pt 4):o539-40.
    PMID: 23634079 DOI: 10.1107/S1600536813006673
    The asymmetric unit of the title salt, C10H11N2 (+)·C4H5O4 (-), consists of two independent 5-amino-6-methyl-quinolin-1-ium cations and two 3-carb-oxy-propano-ate anions. Both cations are protonated at the pyridine N atoms and are essentially planar, with maximum deviations of 0.026 (3) and 0.016 (2) Å. In the crystal, the cations and anions are linked via N-H⋯O and O-H⋯O hydrogen bonds, forming a layer parallel to the ab plane. In the layer, weak C-H⋯O hydrogen bonds and π-π stacking inter-actions, with centroid-to-centroid distances of 3.7283 (15) and 3.8467 (15) Å, are observed. The crystal structure also features weak C-H⋯O hydrogen bonds between the layers.
  12. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Apr 1;69(Pt 4):o537-8.
    PMID: 23634078 DOI: 10.1107/S160053681300665X
    In the 5-chloro-salicylate anion of the title salt, C5H6BrN2 (+)·C7H4ClO3 (-), an intra-molecular O-H⋯O hydrogen bond with an S(6) graph-set motif is formed, so that the anion is essentially planar with a dihedral angle of 1.3 (5)° between the benzene ring and the carboxyl-ate group. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms via a pair of N-H⋯O hydrogen bonds, forming an R 2 (2)(8) ring motif. The crystal structure also features N-H⋯O and weak C-H⋯O inter-actions, resulting in a layer parallel to the (10-1) plane.
  13. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Mar 1;69(Pt 3):o319-20.
    PMID: 23476518 DOI: 10.1107/S1600536813002547
    The asymmetric unit of the title compound, 2C10H11N2(+)·2C3H3O4(-)·C3H4O4, consists of one 5-amino-6-methyl-quinolin-1-ium cation, one hydrogen malonate (2-carb-oxy-acetate) anion and one-half mol-ecule of malonic acid which lies on a twofold rotation axis. The quinoline ring system is essentially planar, with a maximum deviation of 0.062 (2) Å for all non-H atoms. In the anion, an intra-molecular O-H⋯O hydrogen bond generates an S(6) ring. In the crystal, the components are linked via N-H⋯O and O-H⋯O hydrogen bonds into layers parallel to the ac plane. The crystal structure also features weak C-H⋯O hydrogen bonds and a π-π stacking inter-action with a centroid-centroid distance of 3.8189 (10) Å.
  14. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    PMID: 23476517 DOI: 10.1107/S1600536813002559
    In the title salt, C6H9N2(+)·C7H4ClO2(-), the 3-chloro-benzoate anion shows a whole-mol-ecule disorder over two positions with a refined occupancy ratio of 0.505 (4):0.495 (4). In the crystal, the cations and anions are linked via N-H⋯O hydrogen bonds, forming a centrosymmetric 2 + 2 aggregate with R2(2)(8) and R4(2)(8) ring motifs. The crystal structure also features a π-π stacking inter-action between the pyridinium rings with a centroid-centroid distance of 3.8339 (9) Å.
  15. Thanigaimani K, Farhadikoutenaei A, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Jan 1;69(Pt 1):o132-3.
    PMID: 23476391 DOI: 10.1107/S160053681205101X
    In the 5-chloro-salicylate anion of the title salt, C6H9N2(+)·C7H4ClO3(-), an intra-molecular O-H⋯O hydrogen bond with an S(6) graph-set motif is observed and the dihedral angle between the benzene ring and the -CO2 group is 1.6 (6)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms via a pair of N-H⋯O hydrogen bonds, forming an R2(2)(8) ring motif. The crystal structure also features N-H⋯O and weak C-H⋯O inter-actions, resulting in a layer parallel to (10-1).
  16. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Jan 1;69(Pt 1):o42-3.
    PMID: 23476427 DOI: 10.1107/S1600536812049483
    The quinoline ring system of the title salt, C11H12NO(+)·HSO4(-), is essentially planar, with a maximum deviation of 0.054 (2) Å for all non H atoms. In the crystal, the cations and anions are linked via N-H⋯O, O-H⋯O and weak C-H⋯O hydrogen bonds, and are stacked respectively in columns along the a axis. π-π stacking inter-actions, with centroid-centroid distances of 3.5473 (12) and 3.6926 (12) Å, are also observed. The crystal studied was an inversion twin with refined components of 0.43 (7):0.57 (7).
  17. Thanigaimani K, Farhadikoutenaei A, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Jan 1;69(Pt 1):o134-5.
    PMID: 23476392 DOI: 10.1107/S1600536812051021
    The 4-chloro-benzoate anion of the title salt, C6H9N2(+)·C7H4ClO2(-), is nearly planar with a dihedral angle of 5.14 (16)° between the benzene ring and the carboxyl-ate group. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds with an R2(2)(8) ring motif. The ion pairs are further connected via N-H⋯O and weak C-H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane. The crystal structure also features a π-π stacking inter-action between the pyridinium and benzene rings with a centroid-centroid distance of 3.7948 (9) Å.
  18. Thanigaimani K, Farhadikoutenaei A, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Jan 1;69(Pt 1):o94-5.
    PMID: 23476474 DOI: 10.1107/S1600536812050374
    The 4-methyl-benzoate anion of the title salt, C6H9N2(+)·C8H7O2(-), is nearly planar, with a dihedral angle of 6.26 (10)° between the benzene ring and the carboxyl-ate group. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds with an R2(2)(8) ring motif, forming an approximately planar ion pair with a dihedral angle of 9.63 (4)° between the pyridinium and benzene rings. The ion pairs are further connected via N-H⋯O and weak C-H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane.
  19. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2013 Jan 1;69(Pt 1):o92-3.
    PMID: 23476473 DOI: 10.1107/S1600536812050386
    In the title mol-ecular salt, C5H8N3(+)·C3H3O4(-), the cation is essentially planar, with a maximum deviation of 0.005 (1) Å for all non-H atoms. In the anion, an intra-molecular O-H⋯O hydrogen bond generates an S(6) ring. In the crystal, the cations and anions are connected via N-H⋯O hydrogen bonds and a weak C-H⋯O inter-action, forming layers parallel to the ab plane.
  20. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    PMID: 23476428 DOI: 10.1107/S1600536812049495
    In the title hydrated salt, C11H12NO(+)·Cl(-)·2H2O, the quinoline ring system is essentially planar, with a maximum deviation of 0.005 (1) Å for all non-H atoms. In the crystal, the three components are linked by O-H⋯O, N-H⋯O, O-H⋯Cl and weak C-H⋯O hydrogen bonds, forming a layer structure parallel to the ac plane. The crystal structure is further stabilized by π-π stacking inter-actions, with centroid-centroid distances of 3.5213 (6) and 3.7176 (6) Å.
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