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81.
In this paper, time-varying photoconductivity (PC) and the photoluminescence (PL) of different complexes were studied. Due to thick polymer layer hindering light penetrating into porous silicon (PS) layer, intrinsic PS luminescence in polymer/PS system disappeared. The physical origin of PL may be related to the recombination mechanisms involving surface defect states such as silicon oxide, siloxene. Due to carrier transfer controlled by different energy barrier, different devices prepared from different doped Si wafer showed opposite current-voltage characteristic. 相似文献
82.
Priya Budhani Sayed Aftab Iqbal Suman Malik Mamta Bhattacharya Liviu Mitu 《Journal of Saudi Chemical Society》2010,14(3):281-285
The present paper deals with the synthesis and characterization of Schiff base complexes of pyrazinamide an antitubercular drug. Metals selected for complexation are copper, silver, gold, zinc, mercury, iron and cobalt. The complexes have been suitably synthesized and isolated in pure powdered form. Analytical data agrees with the compositions M(L), M′(L)2 and M″(L)2·2H2O, respectively where M = Ag, M′ = Cu, Au, Zn and Hg and M″ = Fe and Co, ligand metal ratios were also confirmed by monovariation method and Job’s method of continuous variation. Molar conductance values suggest the non ionic nature of the complexes. The tentative structure assigned to the complexes on the basis of stoichiometry and analytical data were further supported by spectral studies viz; IR, NMR, magnetic susceptibility and electronic spectra. A preliminary attempt has also been made to compare the potencies of metal complexes with parent drug. The Cu and Ag complexes are giving encouraging results. Particle size studies further suggest that the drug molecule undergoes reduction in size on complexation. 相似文献
83.
84.
Adam Huczyski Daniel owicki Bogumil Brzezinski Franz Bartl 《Journal of Molecular Structure》2008,879(1-3):14-24
A new 2-(2-methoxyethoxy)ethyl ester of Monensin A (MON7) has been synthesized and its capability of complex formation with Li+, Na+, and K+ cations has been studied by ESI MS, 1H and 13C NMR, FT-IR, and PM5 semiempirical methods. ESI mass spectrometry indicates that MON7 forms complexes with Li+, Na+, and K+ of exclusively 1:1 stoichiometry which are stable up to cv = 70 V. The formation of complexes between MON7 and Na+ cations is strongly favored. Starting from about cv = 90 V fragmentation of the respective complexes is observed, primarily characterized by several dehydration steps. The structures of the MON7 complexes with Li+, Na+, and K+ cations are stabilized by intramolecular hydrogen bonds in which the OH groups are always involved. The structures are visualized and discussed in detail. It has been proved that the formation of a pseudo crown ring structure formed by MON7 is preferred in complexes with Na+ cations. 相似文献
85.
86.
Grard Jaouen Siden Top Anne Vessires Roger Alberto 《Journal of organometallic chemistry》2000,600(1-2):23-36
Two series of particular examples of reactions used in bioorganometallic chemistry are described. One based on a decomplexation-complexation reaction, indicates how, starting from a cymantrenyl derivative, a range of organometallic complexes bearing various metals can be prepared. The second one refers to the easy synthesis in water of the very versatile Alberto's reagent, which leads to new organometallic radiopharmaceuticals of Tc and Re. 相似文献
87.
88.
Heinz Falk Helmut Marko Norbert Müller Wolfgang Schmitzberger Hugo Stumpe 《Monatshefte für Chemie / Chemical Monthly》1990,121(11):893-901
Summary Apomyoglobin was reconstituted with bile pigments of the verdinoid, 2,3-dihydroverdinoid, pterobilinoid, and violinoid type. Absorption and circular dichroism data as well as formation constants of the complexes were measured. From these results it was concluded that chromophore binding and induced chirality of these pigments are mainly governed by a lipophilic region opposite to the propionic side chain(s) and the asymmetric position of the hydrogen bonding acceptors of the propionic acid side chain(s) at the entrance of the protein pocket.Dedicated to Prof. Dr. A. Eschenmoser on occasion of his 65th birthday 相似文献
89.
Gerd Meyer Prof. Dr. 《无机化学与普通化学杂志》2008,634(15):2729-2736
90.
The reaction of [ReOBr3(AsPh3)2] with 8-hydroxy-2-methylquinoline-7-carboxylic acid (Hhmquin-7-COOH) has been examined and the [ReOBr2(hmquin-7-COOH)(AsPh3)] complex has been obtained. It was characterized by IR, UV–vis spectroscopy, and single crystal X-ray analysis. The nature
of the frontier orbitals and the electronic transitions involved in the absorption spectrum have been studied by means of
density functional and time-dependent density functional calculations. 相似文献