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21.
M. Nethaji C. Rufes C. Sadasivan Vasantha Pattabhi O. P. Sharma 《Journal of chemical crystallography》1993,23(6):469-472
(I)Lantadene-B: C35H52O5,M
r
=552.80, MonoclinicC2,a=25.65(1),b=6.819(9),c=18.75(1) Å,=100.61(9),V=3223(5) Å3,Z=4,D
x
=1.14 g cm–3 CuK (=1.5418A),=5.5 cm–1,F(000)=1208,R=0.118,wR=0.132 for 1527 observed reflections withF
o
2(F
o
). (II)Lantadene-C: C35H54O5·CH3OH,Mr=586.85, Monoclinic,P21,a=9.822(3),b=10.909(3),c=16.120(8)Å,=99.82(4),V=1702(1)Å3,Z=2,D
x
=1.145 g cm–3, MoK (=0.7107Å), =0.708 cm–1
F(000)=644,R=0.098, wR=0.094 for 1073 observed reflections. The rings A, B, C, D, and E aretrans, trans, trans, cis fused and are in chair, chair, sofa, half-chair, chair conformations, respectively, in both the structures. In the unit cell the molecules are stabilized by O-HO hydrogen bonds in both the structures, however an additional C-HO interaction is observed in the case of Lantadene-C.DCB Contribution No 809. 相似文献
22.
K Vasantha Mary P A Angeli S Dhanuskodi 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(2):311-316
Electron paramagnetic resonance (EPR) of vanadyl ion as an impurity in polycrystalline zinc tris thiourea sulfate (ZTS), a prominent nonlinear optical host, has been studied at X-band frequencies at room temperature. Spin-Hamiltonian parameters and molecular orbital coefficients have been calculated. The optical absorption spectra have also been studied to deduce the crystal field parameters. 相似文献
23.
John Texter Vivek Arjunan Vasantha Rene Crombez Rafael Maniglia Lisa Slater Thomas Mourey 《Macromolecular rapid communications》2012,33(1):69-74
The controlled atom transfer radical polymerization of an ionic liquid, 1‐(11‐acryloylundecyl)‐3‐methyl imidazolium bromide (ILBr), from both ends of a telechelic poly(propylene oxide) (PPO) macroinitiator, end‐functionalized with bromoisobutyryloyl is reported. The resulting highly water‐soluble triblock, poly(ILBr‐b‐PO‐b‐ILBr) is multistimuli responsive. This new class of triblocks exhibits classical surface activity in lowering surface tension at the air–water interface and in modifying wetting in waterborne coatings. It also immunizes model colloids against coagulation induced by Debye–Hückel (indifferent electrolyte) electrostatic screening. Further, sol–gel thermoreversibility is unexpectedly found as an additional form of stimuli responsiveness. 相似文献
24.
K.M. Prabhu Kumar B.C. Vasantha Kumar P. Raghavendra Kumar Ray J. Butcher H.K. Vivek P.A. Suchetan H.D. Revanasiddappa Sabine Foro 《应用有机金属化学》2020,34(6):e5634
A novel selenated Schiff base (S) -L 1 H has been synthesized from (2S)-1-(benzylselanyl)-3-phenylpropan-2-amine which upon reduction formed a reduced Schiff base (S) -L 2 H . Palladium (II) complexes (S) -1 and (S) -2 of ligands (S) -L 1 H and (S) -L 2 H respectively were successfully synthesized. The structures of all four compounds were thoroughly identified by analytical and various spectroscopic techniques. The absolute molecular structures of the above two complexes were further confirmed by single crystal X-ray diffraction. Both (S) -L 1 H and (S) -L 2 H coordinated as monobasic ((S) -L 1–2 ), chelating, tridentate (Se,N,O−) ligands resulting in the complexes of composition (S) - [PdCl( L 1/2 )] [(S) -1/2 ]. In the crystals of complexes (S) -1 and (S) -2 , there were moderate to strong Se⋯O, CH⋯Cl and CH⋯O types of intermolecular secondary interactions. CT-DNA binding activity of these selenium-containing ligands and their palladium complexes bearing a Pd–Se bond have been evaluated for the first time by performing electronic absorption titration and fluorescence emission quenching using CT-DNA-EB and viscometric experiments. These ligands and complexes exhibited remarkable DNA binding activity as shown by their intrinsic DNA binding constants (Kb) and Stern–Volmer constants (Ksv) in the ranges 5.2–9.9 × 104 and 3.6–4.7 × 104, respectively. The viscosity of CT-DNA decreases with increasing concentration of these compounds. The results of the DNA-binding studies revealed that all of the compounds interact with DNA at a minor groove which was further confirmed by molecular docking studies. 相似文献
25.
26.
27.
28.
The title compound is orthorhombic witha = 26·132(6),b = 11·023(2),c = 8·317(5), ?; space group Iba2;Z = 8,D
m
= 1·21(1),D
c
= 1·192 Mg m−3, 1/2(H2O) per molecule in asymmetric unit; λ (MoKα) = 0·7107A; μ = 0·46 cm−1; F(000) = 936. The structure was solved by direct methods and refined to R(F) value of 0·069 using 327 reflections withF ≥ 5σ(F) out of 727 independent reflections for2τ max = 46°. Thetrans fused cyclohexane and cyclohexanone rings form layers along thea-b plane. The axial methyl attached at the bridge-head, interlocks with the translated methylene of the cyclobutane fused across
the cyclohexane ring. The equatorial hydroxyl at the bridge-head adjacent to the methyl junction and the water molecule on
the two-fold form a water bridge along thez axis. The packing is reminiscent of that observed for the cholesterols used in membrane structure studies. 相似文献
29.
A new class of S-linked 1,3,4-oxadiazole-tethered Nα-protected peptidomimetics is designed and synthesized by a reaction of Nα-Z/Boc-protected 1,3,4-oxadiazole-2-thiol with α-bromo ester derived from amino acid. The protocol has also been employed for the synthesis of glycosylated amino acids and N,N′-orthogonally protected dipeptidomimetics bearing S-linked 1,3,4-oxadiazole mimetics as well. The intermediate 5-alkyl amino-1,3,4-oxadiazole-2-thiols have been isolated as stable compounds. Further, the chain extension at both N- and C-termini of N-protected S-linked 1,3,4-oxadiazole tethered dipeptidomimetics was also demonstrated. 相似文献
30.
Cobalt(II)–metformin complexes containing α‐diimine/α‐diamine as auxiliary ligand: DNA binding properties
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The cobalt(II) complexes [Co(Cl)2(met)(o‐phen)] ( 1 ), [Co(Cl)2(en)(met)] ( 2 ) and [Co(Cl)2(met)(opda)] ( 3 ) (met = metformin, o‐phen = ortho‐phenanthroline, en = ethylenediamine, opda = ortho‐phenylenediamine) were synthesized and characterized using liquid chromatography–mass spectrometry, elemental analysis, molar conductance measurements, thermal analysis, infrared spectroscopy, magnetic moment measurements, electronic spectroscopy and X‐ray diffraction. The metal centre was found to be in an octahedral geometry. UV–visible absorption, fluorescence and viscosity measurements were conducted to assess the interaction of the complexes with calf thymus DNA. The complexes showed absorption hyperchromism in UV–visible spectra with DNA. The binding constants from UV–visible absorption studies were 1.38 × 105, 2.1 × 105 and 3.1 × 105 M?1 for 1 , 2 and 3 , respectively, and Stern–Volmer quenching constants from fluorescence studies were 0.146, 0.176 and 0.475, respectively. Viscosity measurements revealed that the binding of the complexes with DNA could be surface binding, mainly due to groove binding. The activities of the complexes in DNA cleavage decrease in the order 3 > 2 > 1 . The complexes were docked into DNA topoisomerase II using Discovery Studio 2.1 software. 相似文献