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151.
152.
Pranita Bora Dr. Basanta Saikia Dr. Bipul Sarma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(3):699-710
Nucleation events and crystal growth can be guided by molecular recognition at interfaces through intermolecular interactions. The short-acting antimicrobial sulfa drug sulfathiazole is known for its concomitant crystallization, which has five known polymorphs, due to conformational flexibility and hydrogen-bond synthon variation. In its development stage of a drug the issue of concomitant crystallization needs to be addressed with respect to patent litigation, including legal actions to protect patents against infringement. A functional self-assembled monolayer (SAM) of organic thiol on a gold surface has been employed as an efficient approach to control concomitant nucleation of such flexible drugs. The crystallization on a SAM surface is mostly kinetically driven and often leads to the nucleation of novel metastable forms. Spectroscopic, thermal analysis and X-ray diffraction studies reveal that a previously unknown, sixth form of the drug nucleates on the designed SAM surface. 相似文献
153.
We report an easy, one pot synthesis to prepare ordered CdS nanocrystals with varying inter-particle separation and characterize
the particle separation using x-ray diffraction at low and wide angles. 相似文献
154.
Nickel boride reductive cleavage of allylic trimethylsilyl ethers yielding alkenes is described. 相似文献
155.
D. D. Sarma F. U. Hillebrecht M. Campagna C. Carbone J. Nogami I. Lindau T. W. Barbee L. Braicovich I. Abbati B. De Michelis 《Zeitschrift für Physik B Condensed Matter》1985,59(2):159-165
We present X-ray absorption spectra (XAS) obtained with synchrotron radiaton at the PdL
2,3 edges of Pd–Al alloys and Bremsstrahlung Isochromat Spectra (BIS) at 1,486.7 eV of Pd–Al alloys and of Pd2Si. The XAS and BIS results for the alloys are very similar indicating that the effect of the core potential (e.g. many-body, electronhole excitation) is negligible. The BIS results on Pd2Si show differences with respect to Pd–Al due to the more localized bonds. The comparison between XAS and BIS data in Pd2Si is still an open problem and might indicate a more subtle role of the core-hole potential. 相似文献
156.
S. Das Sarma 《Solid State Communications》1985,54(12):1067-1071
The problem of the sharpness of the polaron self-trapping transition for a single electron placed in the conduction band of an insulator and interacting with the phonons of the underlying lattice is investigated within the Fröhlich Hamiltonian. It is shown that this phenomenon depends sensitively on the lattice dimensionality, the nature of the electron-phonon coupling, the nature of the phonon dispersion; and on the discrete or the continuum nature of the applicable Hamiltonian. 相似文献
157.
C-isoprenylation of phenols has been effected using a combination of isoprene and in situ generated iodotrimethylsilane or hydrogen iodide. 相似文献
158.
D. D. Sarma W. Speier L. Kumar C. Carbone A. Spinsanti O. Bisi A. Iandelli G. L. Olcese A. Palenzona 《Zeitschrift für Physik B Condensed Matter》1988,71(1):69-74
The electronic properties of calcium silicides (CaSi and CaSi2) are investigated through a joint experimental and theoretical study using Bremsstrahlung Isochromat spectroscopy (BIS) and self-consistent calculation of the electronic states by the Linear Muffin-Tin Orbitals (LMTO) method in the Atomic Sphere Approximation (ASA). The peculiar crystal structure of CaSi2 with two inequivalent Si atoms is responsible for a well defined BIS feature. We found that the calculated high energy DOS features are consistently lower in energy compared to the BIS spectra. Inclusion of the cross-sections of different states into the calculations improves the agreement between the experimental spectra and the calculated curve. We also show that considerable covalent character is present in the bond of calcium silicides. 相似文献
159.
Synthesis and studies on some five-coordinate ruthenium(II) complexes, viz. [Ru(MPh3)(C6H5CHO)2Cl2] and [Ru(MPh3)2(CO)Cl2] (where M = P or As) have been described. Reactions of [Ru(MPh3)(C6H5CHO)2Cl2] with N,N-dimethylformamide, dimethylsulphoxide and pyridine and of [Ru(MPh3)2(CO)Cl2] with pyridine are described. 相似文献
160.