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71.
The crystal structure of the potential antitumor metal compound, viz. chloro, mono(phenanthrenequinone thiosemicarbazonato) palladium(II) dimethyl formamide solvate, is reported. The central palladium(II) atom is in a square planar environment provided by the tridentate, monoanionic thiosemicarbazone ligand and the ancillary chloride ion. The compound exhibited remarkable activity against drug-sensitive and drug-resistant breast cancer cell lines and was relatively nontoxic toward the normal mammary epithelial cells. The drug-induced killing effect against breast cancer cell lines was predominantly mediated via apoptosis, a physiologic form of cell death. 相似文献
72.
A convenient and nonreductive deiodination is reported for the ortho-iodo-hydroxylated arenes including derivatives of quinolinol, phenol, and naphthol. Tertiary amines pyridine, triethylamine, and N-methylmorpholine in the presence of water initiated deiodination of ortho-iodo-hydroxylated arenes without affecting para-iodine and other reduction-susceptible groups. This reported method also works efficiently for polyiodinated systems. Simplicity, short reaction times, and absence of reducing catalyst are features of this method. 相似文献
73.
Arseniyadis S Subhash PV Valleix A Mathew SP Blackmond DG Wagner A Mioskowski C 《Journal of the American Chemical Society》2005,127(17):6138-6139
We have described a spectacular salt effect in the kinetic resolution of (+/-)-1-phenylethylamine, which leads to an increase in reactivity, high levels of selectivity, and a complete reversal of the stereoselectivity. By tuning the reaction conditions, we were able to increase the selectivity factor of (1S,2S)-1 to s = 115. 相似文献
74.
Miao J Chen CC Song C Nishino Y Kohmura Y Ishikawa T Ramunno-Johnson D Lee TK Risbud SH 《Physical review letters》2006,97(21):215503
In combination of direct phase retrieval of coherent x-ray diffraction patterns with a novel tomographic reconstruction algorithm, we, for the first time, carried out quantitative 3D imaging of a heat-treated GaN particle with each voxel corresponding to 17 x 17 x 17 nm3. We observed the platelet structure of GaN and the formation of small islands on the surface of the platelets, and successfully captured the internal GaN-Ga2O3 core shell structure in three dimensions. This work opens the door for nondestructive and quantitative imaging of 3D morphology and 3D internal structure of a wide range of materials at the nanometer scale resolution that are amorphous or possess only short-range atomic organization. 相似文献
75.
Knowledge of the dynamical changes in molecular configurations in various amino acid structures over a wide range of time scales is important since such changes may influence the structural transformations and the diverse biological functionalities of proteins. Using the temperature dependence of the rotating-frame NMR spin-lattice relaxation times T(1rho) of protons as a probe, we have investigated the low-frequency (approximately 60-100 kHz) dynamics in the crystal structures of L-, D-, and DL- alanine (C(12)H(28)O(8)N(4)) polymorphs. The proton relaxation times T(1rho) were obtained from (13)C <-- (1)H and (15)N <-- (1)H cross-polarization magic-angle-spinning NMR experiments over a temperature range of 192-342 K. The data reveal that the time scales of these low-frequency dynamical processes are distinctly different from the localized, high-frequency rotational motion of methyl and amine groups. The strongly asymmetric T(1rho) versus temperature curves and the subtle dynamical differences between the DL-alanine and the L- and d-enantiomorphs indicate that these low-frequency processes are cooperative in nature and are sensitive to molecular packing. 相似文献
76.
Collective syntheses of five spiro[4.5]decane framework bearing sesquiterpenoids, namely, α & β-vetispirenes, β-vetivone, agarospirol and hinesol as well as formal synthesis of axenol and gleenol from a readily available precursor cyclohexanone-β-ketoester via the intermediacy of a versatile intermediate (2,10-dimethylspiro[4.5]dec-1-en-6-one) have been accomplished in a concise manner. 相似文献
77.
78.
Avinash Kumbhar Pramila Sonawane Subhash Padhye Douglas X. West Ray J. Butcher 《Journal of chemical crystallography》1991,27(9):533-539
The structures of two antitumor agents, 2-acetylpyridinethiosemicarbazone hemihydrate (1), C18H11N4O0.5S, colorless,M
r
203.3, monoclinic,P21
lc,a=16.713(3),b=9.460(2),c=12.642(2) ?, β=97.60(1)°,V=1981.2(6) ?3,Z=8,R=0.054,R
w
=0.085 and 2-acetylpyridinethiosemicarbazone hydrochloride (2), C18H12N4SCl, yellow,M
r
=230.7, monoclinic,P21
ln,a=7.676(2),b=7.889(1),c=17.452(4), ?, β=100.96(2)°,V=1037.5(4) ?3
Z=4,R=0.041,R
w
=0.076, have been determined. Both compounds exhibit an E configuration(S atomtrans to the N atom of the hydrazine group). Three hydrogen bonds link the two crystallographically independent molecules in a
pairwise fashion in the hemihydrate. An intramolecular N−H...Cl bond lends extra conformational stability to the hydrochloride
salt. 相似文献
79.
V. G. Puranik S. S. Tavale A. S. Kumbhar R. G. Yerande S. B. Padhye R. J. Butcher 《Journal of chemical crystallography》1992,22(6):725-731
The structure of the new tetranucleating ligand 2,3,-dihydroxy benzenemethanimine -(2-hydroxymethyl)phenyl has been determined by X-ray diffraction techniques. C14H13NO3 is monoclinic, space groupP21/a, with cell dimensionsa=10.382(2),b=19.147(1),c=12.799(1) Å,=113.08(1)°,V=2340.6(3) Å3,Z=8,M=243.04,D
o=1.36,D
x=1.38 mg/m3,F(000)=1024,T=293 K,R=0.041 for 2640 observed reflections. There are two molecules in the asymmetric unit and both have a similar geometry. The molecules are parallel to each other, the distance between them being 3.7 Å and the dihedral angle between mean planes 7.8°. There is a pseudocenter between molecule A and (1–x, 1–y, 1–z) of molecule B. The structure is stabilized by intramolecular O-HN and intermolecular O-HO as well as by C-HO hydrogen bonds.NCL Communication No. 5332. 相似文献
80.
The thermodynamics of CdSe quantum dots embedded in a glass matrix is of great interest because of the numerous applications as optical materials. In this study, the energetics and stability of CdSe quantum dots in a borosilicate glass matrix is investigated as a function of size using high-temperature oxide melt solution calorimetry. CdS0.1Se0.9 nanoparticles (1-40 nm) embedded in glass were analyzed by photoluminescence spectroscopy, electron microprobe, X-ray fluorescence, high-energy synchrotron X-ray diffraction, and (scanning) transmission electron microscopy using both electron energy loss and energy dispersive X-ray spectroscopy. As CdSe particles coarsen, their heat of formation becomes more exothermic. The interfacial energy of CdSe QDs embedded in a borosilicate glass, determined from the slope of enthalpy of drop solution versus calculated surface area, is 0.56 ± 0.01 J/m2. 相似文献