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51.
O. Altan Bozdemir Dr. Yusuf Cakmak Fazli Sozmen Tugba Ozdemir Aleksander Siemiarczuk Dr. Engin U. Akkaya Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(21):6346-6351
Multichromophoric boron‐dipyrromethene (Bodipy) dyes synthesized on phenylene‐ethynylene platforms have been be converted to energy transfer cassettes in a one‐step chemical transformation. Excitation energy transfer processes in these highly symmetrical derivatives were studied in detail, including time‐resolved fluorescence spectroscopy techniques. Excitation spectra and the emission lifetimes suggest efficient energy transfer between the donor and acceptor chromophore. These novel energy transfer cassettes, while highlighting a short‐cut approach to similar energy transfer systems, could be useful as large pseudo‐Stokes shift multichromophoric dyes with potential applications in diverse applications. 相似文献
52.
A series of N-ethylpiperazine substitute thioureas [C6N2H13NHCSNHR], where R = -C3H5 (L 1 ), -C10H7 (L 2 ), and -C7H7 (L 3 ), and their copper (II) complexes have been synthesized. These ligands and complexes have been characterized by elemental analyses, IR, 1H and 13C-NMR spectra, UV-Vis, magnetic susceptibility, thermogravimetrical analyses, and MALDI-TOF MS. In vitro antitumor activity of ligands and their complexes has been screened toward several tumor cell lines. The effects on these complexes of the growth of L1210 and MCF7 were studied comparatively with that of free ligands. Antioxidant and radical scavenging activities of synthesized compounds were determined by various in vitro assays including 1,1-diphenyl-2-picryl-hydrazyl free radicals (DPPH), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid radicals (ABTS+), and ferrous ion (Fe2+) chelating activities. Moreover, these activities were compared to synthetic and standard antioxidant trolox. The results showed that the synthesized compounds had effective antioxidant power. 相似文献
53.
54.
Raman Spectra of the System PCl5? TeCl4 Raman spectra of solid and molten PCl5? TeCl4 mixtures have been recorded. The solid 1:1 mixture contains the compound nPCl4 + (TeCl5?)n. In the molten state there are different fragmentation equilibria between the polymeric (TeCl5)?n, TeCl62?, and lower charged units. The spectra of TeCl4 rich samples indicate different species like Te3Cl13?, Te2Cl102?, and (TeCl5?)n. In such melts the equilibria are shifted to lower charged oligomeres and TeCl5?. 相似文献
55.
?zen??zgenEmail author Semra?Koyuno?lu Engin?Kendi Akgül?Ye?ilada 《Structural chemistry》2005,16(1):61-65
There are two molecules in the asymmetric unit (I and II). The structure consists of a 2-pyrazoline ring and three aromatic rings two of which are free and the third one is condensed with a 3-methyl-4(3H)-pyrimidine ring (4(3H)-Quinazolinone). While the pyrazoline ring is in the distorted envelope conformation, the free aromatic rings are planar and the pyrimidine ring deviates from the planarity. The crystal structure is stabilized by C–HO inter and intramolecular bonds. 相似文献
56.
Gülgün Ayhan Kilcigil Rahmiye Ertan Süheyla
zbey Engin Kendi 《Journal of heterocyclic chemistry》1998,35(6):1485-1492
In this study, it is aimed to investigate the synthesis and the calcium antagonistic activity of some flavone derivatives which contain the 1,4-dihydropyridine ring system at the A ring of the flavone nucleus. For this purpose we first synthesized 6-formylflavone and then twelve 1,4-dihydropyridine derivatives were synthesized by the reaction of 6-formylflavone with alkylacetoacetates, acetoacetanilide and methyl or ethyl aminocrotonate. Conformational analysis was performed for compound 3a . The calcium antagonistic activity of compound 2a was examined using nifedipine as the reference compound. 相似文献
57.
The miscibility and morphology of poly(ε-caprolactone) (PCl) and poly(para-chlorostyrene) (PpClS) blend were investigated by using thermal analysis, morphological analysis, viscometry, and the study of melting point depression. A single glass transition temperature was observed by differential scanning calorimetry (DSC) for PCl/PpClS blends in the whole compositional range (0/100, 25/75, 50/50, 62.5/37.5, 75/25, 90/10). Morphology of the polymers and their blends was studied by scanning electron microscopy (SEM). The Fourier transform infrared spectra of the samples were obtained by spectrometer. Up to 12 cm−1 shifts in carbonyl stretching band of PCl was detected in the spectra of PpClS rich blends. The viscosity of PCl, PpClS and their blends has also been studied to investigate the miscibility according the miscibility criteria Δb, and Δ[η]. Using this data, the interaction parameters α and μ, based on the Chee and Sun et al. approaches were determined. These criteria indicated that the blend is miscible in all proportions up to 90% of PCl content in the blends. The melting point depression of PCl in the blends was examined to obtain the interaction parameter, χ12 for this system. The parameter, χ12 was found to be composition dependent. Negative values of the obtained interaction parameter also support the miscibility of this system up to the 90% PCl in the blend. 相似文献
58.
In the two title compounds, the 2-methyl-1,3-dioxoindan-2-yl and 4-(brom; ethoxy) phenyl groups aretrans with respect to one another. The phenyl ring and the azo group are not coplanar in the two molecules. The five-membered rings of the two compounds adopt an envelope conformation. The crystallographic parameters are as follows: 2-Methyl-2-(4-bromphenylazo)-1,3-indandione (I): monoclinic, P21/a witha=8.098(2),b=14.442(2),c=12.554(1)Å, =100.55(2)o, andD
calc=1.58 g cm–3 forZ=4; 2-methyl-2-(4-ethoxyphenylazo)-1, 3-indandione (II): monoclinic, P21/a witha=8.258(2),b=14.449(1),c=13.559(2)Å, =101.19(1)o, andD
calc=1.29 g cm–3 forZ=4. 相似文献
59.
In the present work, based on a one-dimensional model, the interaction of two solitary waves propagating in opposite directions in a collisionless plasma is investigated by use of the extended Poincaré–Lighthill–Kuo (PLK) method. It is shown that bi-directional solitary waves are propagated and the head-on collision of these two solitons occur. The phase shifts and the trajectories of these two solitons after the collision are obtained. 相似文献
60.