Displaying publications 1 - 20 of 34 in total

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  1. 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.
  2. 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.
  3. Khalib NC, Thanigaimani K, Arshad S, Razak IA
    PMID: 24046675 DOI: 10.1107/S1600536813016310
    In the title salt, C6H9N2 (+)·C7H5O3 (-), the anion is essentially planar, with a dihedral angle of 2.72 (17)° between the benzene ring and the carboxyl-ate group. In the crystal, the anions are connected by O-H⋯O hydrogen bonds, forming a 41 helical chain along the c axis. 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. The ion pairs are further connected via another N-H⋯O hydrogen bond, resulting in a three-dimensional network.
  4. Farhadikoutenaei A, Thanigaimani K, Arshad S, Razak IA
    PMID: 24046674 DOI: 10.1107/S1600536813016322
    In the 3-hy-droxy-picolinate anion of the title salt, C6H9N2 (+)·C6H4NO3 (-), 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 9.55 (9)° between the pyridine ring and the carboxyl-ate group. In the crystal, the cations and anions are linked via N-H⋯O hydrogen bonds, forming a centrosymmetric 2 + 2 aggregate with R 2 (2)(8) and R 4 (2)(8) ring motifs. The crystal structure also features N-H⋯N and weak C-H⋯π inter-actions.
  5. 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.
  6. 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.
  7. 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.
  8. Thanigaimani K, Razak IA, Arshad S, Jagatheesan R, Santhanaraj KJ
    Acta Crystallogr Sect E Struct Rep Online, 2012 Oct 1;68(Pt 10):o2910.
    PMID: 23125702 DOI: 10.1107/S1600536812038019
    In the title compound, C(10)H(11)N(5)O, the triazine ring forms a dihedral angle of 10.37 (4)° with the benzene ring. In the crystal, adjacent mol-ecules are linked by a pair of N-H⋯N hydrogen bonds, forming an inversion dimer with an R(2) (2)(8) ring motif. The dimers are further connected via N-H⋯O and N-H⋯N hydrogen bonds, resulting in a three-dimensional network.
  9. Thanigaimani K, Razak IA, Arshad S, Jagatheesan R, Santhanaraj KJ
    Acta Crystallogr Sect E Struct Rep Online, 2012 Oct 1;68(Pt 10):o2938-9.
    PMID: 23125724 DOI: 10.1107/S1600536812038743
    The asymmetric unit of the title compound, 2C(10)H(11)N(5)O·C(6)H(10)O(4), consists of a 2,4-diamino-6-(4-meth-oxy-phen-yl)-1,3,5-triazine mol-ecule and one-half mol-ecule of adipic acid which lies about an inversion center. The triazine ring makes a dihedral angle of 12.89 (4)° with the adjacent benzene ring. In the crystal, the components are linked by N-H⋯O and O-H⋯N hydrogen bonds, thus generating a centrosymmetric 2 + 1 unit of triazine and adipic acid mol-ecules with R(2) (2)(8) motifs. The triazine mol-ecules are connected to each other by N-H⋯N hydrogen bonds, forming an R(2) (2)(8) motif and a supra-molecular ribbon along the c axis. The 2 + 1 units and the supra-molecular ribbons are further inter-linked by weak N-H⋯O, C-H⋯O and C-H⋯π inter-actions, resulting in a three-dimensional network.
  10. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2012 Dec 1;68(Pt 12):o3343.
    PMID: 23476180 DOI: 10.1107/S1600536812046156
    The asymmetric unit of the title compound, 2C5H6ClN3O·C4H6O4, consists of one 4-chloro-6-meth-oxy-pyrimidin-2-amine mol-ecule and one half-mol-ecule of succinic acid which lies about an inversion centre. In the crystal, the acid and base mol-ecules are linked through N-H⋯O and O-H⋯N hydrogen bonds, forming a tape along [1-10] in which R2(2)(8) and R4(2)(8) hydrogen-bond motifs are observed. The tapes are further inter-linked through a pair of C-H⋯O hydrogen bonds into a sheet parallel to (11-2).
  11. Thanigaimani K, Khalib NC, Farhadikoutenaei A, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2012 Dec 1;68(Pt 12):o3321-2.
    PMID: 23476164 DOI: 10.1107/S1600536812045308
    In the title salt, 2C4H6ClN4(+)·C4H2O4(2-), the complete fumarate dianion is generated by crystallographic inversion symmetry. The cation is essentially planar, with a maximum deviation of 0.018 (1) Å. In the anion, the carboxyl-ate group is twisted slightly away from the attached plane, the dihedral angle between the carboxyl-ate and (E)-but-2-ene planes being 12.78 (13)°. 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, forming an R2(2)(8) ring motif. In addition, another type of R2(2)(8) motif is formed by centrosymmetrically related pyrimidinium cations via N-H⋯N hydrogen bonds. These two combined motifs form a heterotetra-mer. The crystal structure is further stabilized by stong N-H⋯O, N-H⋯Cl and weak C-H⋯O hydrogen bonds, resulting a three-dimensional network.
  12. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2012 Dec 1;68(Pt 12):o3318.
    PMID: 23476162 DOI: 10.1107/S160053681204528X
    The title compound, C5H6ClN3O, is essentially planar with a maximum deviation of 0.0256 (11) Å for all non-H atoms. In the crystal, adjacent mol-ecules are linked by a pair of N-H⋯N hydrogen bonds, forming an inversion dimer with an R2(2)(8) ring motif. The dimers are further linked via N-H⋯O hydrogen bonds into an undulating sheet structure parallel to the bc plane.
  13. Thanigaimani K, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2012 Dec 1;68(Pt 12):o3442-3.
    PMID: 23476258 DOI: 10.1107/S160053681204768X
    The benzoic acid mol-ecule of the title compound, C4H5ClN4·C7H6O2, is approximately planar, with a dihedral angle of 1.28 (9)° between the carb-oxy group and the benzene ring. In the crystal, two acid and two base mol-ecules are linked through N-H⋯O and O-H⋯N hydrogen bonds, forming a centrosymmetric 2 + 2 unit with R2(2)(8) and R4(2)(8) motifs. These units are further linked through a pair of N-H⋯N hydrogen bonds into a tape structure along [1-20]. The crystal structure also features weak π-π [centroid-centroid distance = 3.5984 (11) Å] and C-H⋯π inter-actions.
  14. Thanigaimani K, Farhadikoutenaei A, Arshad S, Razak IA, Balasubramani K
    Acta Crystallogr Sect E Struct Rep Online, 2012 Dec 1;68(Pt 12):o3415-6.
    PMID: 23476237 DOI: 10.1107/S1600536812046338
    The base mol-ecule of the title co-crystal, C7H10N2O2S·C7H6O3, is essentially planar, with a maximum deviation of 0.0806 (14) Å for all non-H atoms. The acid mol-ecule is also nearly planar, with a dihedral angle of 8.12 (14)° between the benzene ring and the carb-oxy group. In the crystal, the acid mol-ecules form an inversion dimer through a pair of O-H⋯O hydrogen bonds with an R2(2)(8) ring motif. The pyrimidine mol-ecules are linked on both sides of the dimer into a heterotetra-mer via O-H⋯N and C-H⋯O hydrogen bonds with R2(2)(8) ring motifs. The heterotetra-mers are further linked by weak C-H⋯O hydrogen bonds, forming a tape structure along [1-10].
  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, 2012 Dec 1;68(Pt 12):o3444-5.
    PMID: 23476259 DOI: 10.1107/S1600536812047642
    In the 4-meth-oxy-quinoline-2-carboxyl-ate anion of the title salt, C5H8N3(+)·C11H8NO3(-), the dihedral angle between the quinoline ring system and the carboxyl-ate group is 16.54 (15)°. In the crystal, the cations and anions are linked via N-H⋯O and N-H⋯N hydrogen bonds, forming a centrosymmetric 2 + 2 aggregate with R2(2)(9) and R4(2)(8) ring motifs. These units are further connected via N-H⋯O hydrogen bonds into a layer parallel to the bc plane. The crystal structure is also stabilized by weak C-H⋯O hydrogen bonds and π-π inter-actions between pyridine rings [centroid-centroid distance = 3.5886 (8) Å] and between pyridine and benzene rings [centroid-centroid distance = 3.6328 (8) Å].
  17. Thanigaimani K, Farhadikoutenaei A, Khalib NC, Arshad S, Razak IA
    Acta Crystallogr Sect E Struct Rep Online, 2012 Nov 1;68(Pt 11):o3151-2.
    PMID: 23284469 DOI: 10.1107/S1600536812041359
    The anion of the title salt, C(6)H(9)N(2) (+)·C(6)H(4)NO(3) (-), undergoes an enol-to-keto tautomerism during the crystallization. In the crystal structure, the cation and anion are held together by a relatively short N-H⋯O hydrogen bond, and the two anions are further connected to each other by a pair of N-H⋯O hydrogen bonds with an R(2) (2)(8) ring motif, thus forming a centrosymmetric 2 + 2 aggregate. The aggregates are further linked through weak N-H⋯O and C-H⋯O hydrogen bonds, resulting a three-dimensional network.
  18. 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.
  19. 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).
  20. 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.
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