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1.
Radhakrishnan M. Packianathan C. Sankaran B. Kandavelu P. Rosen B. P. 《Crystallography Reports》2021,66(7):1311-1315
Crystallography Reports - Exposure to environmental arsenic is associated with serious of health issues such as cancer, diabetes and developmental delays in infants and children. In human liver,... 相似文献
2.
Samson?Jegan?Jennifer Packianathan?Thomas MuthiahEmail author Duraiswamy?Tamilselvi 《Chemistry Central journal》2014,8(1):58
Background
Most of the benzyladenine and furfuryladenine derivatives inhibit tumor/cancer cell growth; their toxicity is lesser than the compounds used for the treatment of cancer now-a-days. Many cytokinin derivatives are tested for anticancer activity.Results
A series of transition metal complexes containing N6-benzyl/furfuryl aminopurines of formula [Mn(FAH)2(H2O)(Cl3)]2.Cl2(1), [Co(FAH)2(H2O)(Cl3)]2.Cl2(2), [Co(FAH)2(Cl4)]2 .[Co(FAH)2(H3O)(Cl3)].Cl2(3), [Ni(FAH)2(H2O)(Cl3)]2.Cl2. (H2O) (4), [Zn(BAH)Br3] (5) and [Cd2(BAH)2(μ-Br)4Br2]n(6) (where BAH and FAH benzyladeninium and furfuryladeninium cations respectively) have been synthesized and characterized. Crystal structures of (1-4) have similar distorted octahedral coordination geometry, while (5) and (6) have distorted tetrahedral geometry and octahedral geometries respectively. In (1-4) two halide ions and two cytokinin cations (BAH+/FAH+) are laterally coordinated to the metal ion. A water molecule and a halide ion are axially coordinated. But the coordination sphere of (5) consists of N7 coordinated benzyladeninium ion and three halide ions. The complex (6) is a coordination polymer bridged by bromide anions. A common notable feature in (1-4) is the presence of one or more lattice chloride anions. They help in a chain formation by N-H…Cl halide involving hydrogen bonding interactions in between the Hoogsteen site hydrogen.Conclusions
The observed crystal structures emphasize the role of the halide ions in developing the supramolecular architectures by halide involving hydrogen bonding interactions. Also most of the reported cobalt cytokinin complexes possess tetrahedral coordination geometry, but some cobalt complexes have distorted octahedral coordination geometry, which are discussed and compared.
3.
Azhagesan Renuga Parameswari Balu Devipriya Samson Jegan Jenniefer Packianathan Thomas Muthiah Poomani Kumaradhas 《Journal of chemical crystallography》2012,42(3):227-231
Abstract
The title compound 5-Hydroxy-1,7-bis-(4-hydroxy-3-methoxy-phenyl)-hepta-1,6-dien-3-one crystallizes in orthorhombic space group Pca21 with two molecules in the asymmetric unit. The unit cell parameters are: a = 35.5368(8), b = 7.7799(2), c = 12.6796(3) ?, D calc = 1.396 Mgm−3, V = 3505.6(2) ?3 and Z = 8. The two aromatic rings in both the molecules are found almost coplanar, their dihedral angles are 18.8° and 13.8°, respectively. The molecular packing is stabilized by strong O–H···O and C–H···O types of hydrogen bonding interactions. The keto and enol groups form an strong O–H···O intra-molecular interaction in both molecules of asymmetric unit. The molecular alignment in the crystal forming a staircase type of stacking through cross link intermolecular interactions. 相似文献4.
Kasthuri Balasubramani Packianathan Thomas Muthiah Daniel E Lynch 《Chemistry Central journal》2007,1(1):1-10
Background
The characterization of three types of Marche (Italy) honeys (Acacia, Multifloral, Honeydew) was carried out on the basis of the their quality parameters (pH, sugar content, humidity) and mineral content (Na, K, Ca, Mg, Cu, Fe, and Mn). Pattern recognition methods such as principal components analysis (PCA) and linear discriminant analysis (LDA) were performed in order to classify honey samples whose botanical origins were different, and identify the most discriminant parameters. Lastly, using ANOVA and correlations for all parameters, significant differences between diverse types of honey were examined.Results
Most of the samples' water content showed good maturity (98%) whilst pH values were in the range 3.50 – 4.21 confirming the good quality of the honeys analysed. Potassium was quantitatively the most relevant mineral (mean = 643 ppm), accounting for 79% of the total mineral content. The Ca, Na and Mg contents account for 14, 3 and 3% of the total mineral content respectively, while other minerals (Cu, Mn, Fe) were present at very low levels. PCA explained 75% or more of the variance with the first two PC variables. The variables with higher discrimination power according to the multivariate statistical procedure were Mg and pH. On the other hand, all samples of acacia and honeydew, and more than 90% of samples of multifloral type have been correctly classified using the LDA. ANOVA shows significant differences between diverse floral origins for all variables except sugar, moisture and Fe.Conclusion
In general, the analytical results obtained for the Marche honeys indicate the products' high quality. The determination of physicochemical parameters and mineral content in combination with modern statistical techniques can be a useful tool for honey classification. 相似文献5.
Jeyaraman Selvaraj Nirmalram Duraisamy Tamilselvi Packianathan Thomas Muthiah 《Journal of chemical crystallography》2011,41(6):864-867
Abstract
N 6-benzyladeninium nitrate, (1), C12H12N5 + NO3 − crystallizes in P2 1/c, with a = 15.0035(13), b = 5.3788(5), c = 16.8954(13) ?, β = 107.331(6)°, Z = 4 and N 6-benzyladeninium 3-hydroxy picolinate, (2), C12H12N5 + C6H4NO3 −, crystallizes in P1, with a = 8.3017(4), b = 14.6170(7), c = 14.7909 (8) ?, α = 78.801 (4), β = 81.979 (4),γ = 88.849 (4)°, Z = 4. In both the salts, the cation exists as N(7)H tautomer with protonation at the N3 atom. The dihedral angle of 76.64 (16)° for (1), 67.91(12)° for (cation A) and 68.27 (13)° for (cation B) in (2), between the adenine plane and phenyl ring plane, the distal orientation of the N6 substituent with respect to the imidazole ring and the free N1 position, make these benzyladeninium cations meet all the requirements necessary for cytokinin activity. The crystal structures are stabilized by N–H···N, N–H···O, C–H···O hydrogen bonds and C–H···π stacking interaction between symmetry related benzyladenine molecule. 相似文献6.
Ammasai Karthikeyan Matthias Zeller Packianathan Thomas Muthiah 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(4):337-340
Zinc thiocyanate complexes have been found to be biologically active compounds. Zinc is also an essential element for the normal function of most organisms and is the main constituent in a number of metalloenzyme proteins. Pyrimidine and aminopyrimidine derivatives are biologically very important as they are components of nucleic acids. Thiocyanate ions can bridge metal ions by employing both their N and S atoms for coordination. They can play an important role in assembling different coordination structures and yield an interesting variety of one‐, two‐ and three‐dimensional polymeric metal–thiocyanate supramolecular frameworks. The structure of a new zinc thiocyanate–aminopyrimidine organic–inorganic compound, (C6H9ClN3)2[Zn(NCS)4]·2C6H8ClN3·2H2O, is reported. The asymmetric unit consist of half a tetrathiocyanatozinc(II) dianion, an uncoordinated 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidinium cation, a 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine molecule and a water molecule. The ZnII atom adopts a distorted tetrahedral coordination geometry and is coordinated by four N atoms from the thiocyanate anions. The ZnII atom is located on a special position (twofold axis of symmetry). The pyrimidinium cation and the pyrimidine molecule are not coordinated to the ZnII atom, but are hydrogen bonded to the uncoordinated water molecules and the metal‐coordinated thiocyanate ligands. The pyrimidine molecules and pyrimidinium cations also form base‐pair‐like structures with an R22(8) ring motif via N—H…N hydrogen bonds. The crystal structure is further stabilized by intermolecular N—H…O, O—H…S, N—H…S and O—H…N hydrogen bonds, by intramolecular N—H…Cl and C—H…Cl hydrogen bonds, and also by π–π stacking interactions. 相似文献
7.
Kaliyaperumal Thanigaimani Annamalai Subashini Packianathan Thomas Muthiah Daniel E. Lynch Ray J. Butcher 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(2):o42-o45
In the crystal structures of 2‐amino‐4,6‐dimethoxypyrimidinium 2,4,6‐trinitrophenolate (picrate), C6H10N3O2+·C6H2N3O7−, (I), and 2,4‐diamino‐5‐(4‐chlorophenyl)‐6‐ethylpyrimidin‐1‐ium (pyrimethaminium or PMN) picrate dimethyl sulfoxide solvate, C12H14ClN4+·C6H2N3O7−·C2H6OS, (II), the 2‐amino‐4,6‐dimethoxypyrimidine and PMN cations are protonated at one of the pyrimidine N atoms. The picrate anion interacts with the protonated cations through bifurcated N—H...O hydrogen bonds, forming R21(6) and R12(6) ring motifs. In (I), Z′ = 2. In (II), two inversion‐related PMN cations are connected through a pair of N—H...N hydrogen bonds involving the 4‐amino group and the uncharged N atom of the pyrimidine ring, forming a cyclic hydrogen‐bonded R22(8) motif. In addition to the pairing, the O atom of the dimethyl sulfoxide solvent molecule bridges the 2‐amino and 4‐amino groups on both sides of the paired bases, resulting in a self‐complementary …DADA… array of quadruple hydrogen‐bonding patterns. 相似文献
8.
Madhukar Hemamalini Packianathan Thomas Muthiah Urszula Rychlewska Agnieszka Plutecka 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(2):o95-o97
In the title compound, C6H10N3+·HSO4−, the asymmetric unit consists of a hydrogen sulfate anion and a 2‐amino‐4,6‐dimethylpyrimidinium cation. The hydrogen sulfate anions self‐assemble through O—H⋯O hydrogen bonds, forming supramolecular chains along the b axis, while the organic cations form base pairs via N—H⋯N hydrogen bonds. The aminopyrimidinium cations join to the sulfate anions via a pair of hydrogen bonds donated from the pyrimidinium protonation site and from the exo amine group cis to the protonated site. 相似文献
9.
Ammasai Karthikeyan Robert Swinton Darious Packianathan Thomas Muthiah Franc Perdih 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(11):985-990
Two novel cocrystals of the N(7)—H tautomeric form of N6‐benzoyladenine (BA), namely N6‐benzoyladenine–3‐hydroxypyridinium‐2‐carboxylate (3HPA) (1/1), C12H9N5O·C6H5NO3, (I), and N6‐benzoyladenine–DL‐tartaric acid (TA) (1/1), C12H9N5O·C4H6O6, (II), are reported. In both cocrystals, the N6‐benzoyladenine molecule exists as the N(7)—H tautomer, and this tautomeric form is stabilized by intramolecular N—H...O hydrogen bonding between the benzoyl C=O group and the N(7)—H hydrogen on the Hoogsteen site of the purine ring, forming an S(7) motif. The dihedral angle between the adenine and phenyl planes is 0.94 (8)° in (I) and 9.77 (8)° in (II). In (I), the Watson–Crick face of BA (N6—H and N1; purine numbering) interacts with the carboxylate and phenol groups of 3HPA through N—H...O and O—H...N hydrogen bonds, generating a ring‐motif heterosynthon [graph set R22(6)]. However, in (II), the Hoogsteen face of BA (benzoyl O atom and N7; purine numbering) interacts with TA (hydroxy and carbonyl O atoms) through N—H...O and O—H...O hydrogen bonds, generating a different heterosynthon [graph set R22(4)]. Both crystal structures are further stabilized by π–π stacking interactions. 相似文献
10.
Samson Jegan Jenniefer Packianathan Thomas Muthiah 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(3):m69-m72
Two isostructural uranyl complexes have been crystallized with different bipyridyl cations to yield the compounds hemi(4,4′‐bipyridinium) tris(5‐chlorothiophene‐2‐carboxylato)dioxidouranate(VI) monohydrate, (C10H10N2)0.5[U(C5H2ClO2S)3O2]·H2O, (I), and hemi[4,4′‐(ethane‐1,2‐diyl)dipyridinium] tris(5‐chlorothiophene‐2‐carboxylato)dioxidouranate(VI) monohydrate, (C12H14N2)0.5[U(C5H2ClO2S)3O2]·H2O, (II). In the [UO2X3]− complexes (X is 5‐chlorothiophene‐2‐carboxylate), the uranyl O atoms occupy the two axial positions and the equatorial positions are occupied by six O atoms of the three X ions so that each U atom is eight coordinated in a puckered hexagonal–bipyramidal structure. In both compounds, the metal centres are linked by classical O—H...O and N—H...O hydrogen bonds involving the coordinated ligands, the diprotonated organic linker cation (which rests on a centre of inversion at the mid‐point of the central C—C bond) and water molecules. The crystal structures are further stabilized by weak C—H...O and π–π stacking interactions, forming similar three‐dimensional supramolecular architectures, forming a two‐dimensional network parallel to the (100) plane in (I) and a three‐dimensional network in (II). 相似文献