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The reactions of Vaska’s complex [IrCl(CO)(PPh3)2] with 2-(coumaryl-6-azo)imidazole (CZ-H) and its derivatives (CZ-X) have synthesized [Ir(CZ)(CO)(PPh3)2] and [Ir(CZ-X)(CO)(PPh3)2]. All the complexes have been characterized by FT-IR, UV-Vis, 1H NMR and FAB-MS spectroscopy. The structural confirmation has been done in one case, by a single crystal X-ray diffraction study, which shows a distorted square pyramidal geometry around the central Ir atom. The complexes are emissive at room temperature. The cyclic voltammetry of the complexes shows a metal centered irreversible oxidation and ligand centered quasireversible reduction couples. To get an insight into the electronic structure, absorption spectra and electrochemical properties, detailed calculations on all three complexes have been performed at the DFT level. 相似文献
124.
In this paper, a permutation-based genetic algorithm (GA) is applied to the NP-hard problem of arranging a number of facilities on a line with minimum cost, known as the single row facility layout problem (SRFLP). The GA individuals are obtained by using some rule-based as well as random permutations of the facilities, which are then improved towards the optimum by means of specially designed crossover and mutation operators. Such schemes led the GA to handle the SRFLP as an unconstrained optimization problem. In the computational experiments carried out with large-size instances of sizes from 60 to 80, available in the literature, the proposed GA improved several previously known best solutions. 相似文献
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126.
Structures and electronic properties of clusters of an all-Si analogue of graphene, silicene, have been studied through quantum chemical calculations. The structures of the six-membered rings show interesting chair like puckering, which for large sheet-like clusters form ordered ripples. Binding energies, HOMO-LUMO gaps and polarizabilities for the silicene clusters show interesting monotonic trends analogous to polyacenes. Stacking of two silicene layers leads to the formation of closed 3D clusters with high symmetry and strong Si-Si bonds. The heat of hydrogenation of silicene to form silicanes is overwhelmingly exothermic and leads to the opening up of the HOMO-LUMO gaps. Thus, analogous to graphanes, silicanes are predicted to be interesting materials for hydrogen storage and for their band engineering properties. 相似文献
127.
Umbelliferyl sugars have been used to determine the lectin concentration in very dilute solution by fluorescence quenching methods. The Stern-Volmer plot of fluorescence quenching after considering ground-state complexation is obeyed by several sugars. As little as 1 μg of lectin (in 10 μl) and 250 nM of umbelliferyl sugars can be determined. This method offers a simple, non-destructive and rapid method for the determination of lectin activity. 相似文献
128.
Anasuya Datta C. M. Srivastava N. Venkataramani 《Physica C: Superconductivity and its Applications》1993,210(3-4):408-412
We have examined the DC electrical resistivity of RE-123 superconductors (where RE is a rare earth element) on the basis of a model of correlated electron transfer arising from the electron-phonon interaction. The small polaron stabilization energy (εp) has been obtained from the fitting of the normal state resistivity data. A correlation between the lattice parameters of the unit cell and εp has been observed which is explained on the basis of fermiology. 相似文献
129.
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
130.
Mn2+ doped In2S3–SiO2 nanocomposite thin films were synthesized by sol-gel technique. The films were annealed in air at different temperatures (473–623 K) and characterized by optical, microstructural and electron spin resonance (ESR) study. Optical transmittance study revealed the manifestation of quantum size effect while ESR indicated the presence of manganese in indium sulphide as dispersed dopant rather than manganese cluster. 相似文献