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41.
Halit Kantekin Ümmühan Ocak Yaşar Gök Irfan Acar 《Journal of inclusion phenomena and macrocyclic chemistry》2004,48(3-4):95-101
A new (E, E)-dioxime (H 2 L) containing a diazadioxadithia macrocyclic moieties has been synthesized by reaction of an aromatic primary amine with cyanogendi-N-dioxide. The BF2 +-capped Ni2+ mononuclear complex of this new oxime has been synthesized using a precursor hydrogen-bridged mononuclear Ni2+ complex. The solvent extraction of transition metal cations by (3) and (6) with picrate anion into chloroform has been studied at 25 °C and UV-visible spectroscopy. The extractability and selectivity of transition metal picrates, (Pb2+, Ni2+, Co2+, Cd2+, Zn2+, Cu2+, Ag+) has been evaluated. The structures of new compounds are identified by using elemental analysis, 1H and 13C-NMR, IR and MS spectral data. 相似文献
42.
Shahabuddin Memon Ashfaque Ali Bhatti Asif Ali Bhatti Ümmühan Ocak Miraç Ocak 《Journal of fluorescence》2016,26(5):1591-1599
Specific functionalized calix[4]arene based fluorescent chemosensor was synthesized for cations and anions binding efficiency examination. Receptor C4MA displayed strong affinity for Al3+and S2O7 2? with enhanced fluorescence intensity. The selective response of C4MA was investigated in the presence of different co-existing competing ions. The limit of detection (LOD) of Al3+and S2O7 2? was calculated as 2.8?×?10?6 M and 2.6?×?10?7 M respectively. Sensor C4MA forms (1:1) stoichiometric complex with both Al3+ and S2O7 2? and their binding constants were calculated as 12.1?×?104 and 8.3?×?103 respectively. Complexes were also characterized through FT-IR spectroscopy. 相似文献
43.
Nazan Ocak İskeleli Hasan Karabıyık Çiğdem Albayrak Hande Petek Erbil Ağar 《Journal of chemical crystallography》2006,36(11):709-714
The molecular and crystal structures of the title compound, C22H16N4O2, were determined by single crystal X-ray diffraction technique. The title compound crystallizes in monoclinic space group P1 2
1
/n1, with a=12.7811(9) ?, b=8.2002(4) ?, c=17.8772(14) ?, Z=4, D
calc=1.3112(1) g/cm3, μ (Mo-Kα)=0.087 mm−1. The structure was solved by direct methods and refined to a final R=0.056 for 1891 reflections with I > 2σ (I). The asymmetric unit in the crystal structure contains only one neutral molecule. The positions of nitrogen atoms in the azo groups were disordered. There is no classic hydrogen bond in the crystal structure. The molecules in the crystal structure are stacked by π–π stacking and one edge-to-face interactions. In order to determine conformational flexibility and crystal packing effects on the molecules, molecular energy profile of the title compound was obtained with respect to the selected torsion angle, which is varied from −180° to +180° in every 10° via PM3 semi-empirical method. 相似文献
44.
45.
The generalized Sinh-Gordon potential is solved within quantum Hamiltonian Jacobi approach in the framework of PT symmetry. The quasi exact solutions of energy eigenvalues and eigenfunctions of the generalized Sinh-Gordon potential are
found for n=0,1 states. 相似文献
46.
The influence of Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, Sr2+, Ba2+, Ag+, Cd2+, Co2+, Fe2+, Hg2+, Mn2+, Pb2+, Zn2+ and Fe3+ on the spectroscopic properties of two dansyl (1-dimethylaminonaphthalene-5-sulfonyl) groups linked to the lower rims of a series of three, structurally related, di-ionized calix[4]arenes is investigated by means of absorption and emission spectrophotometry. Di(tetramethylammonium) salts of the di-ionized ligands, L, L1, and L2, which differ in having no, two and four allyl groups, respectively, on the upper rim of the calix[4]arene scaffold, are utilized for the spectrofluorimetric titration experiments in MeCN. On complexation by alkaline earth metal cations, the emission spectra undergo marked red shifts and quenching of the dansyl fluorescence. These effects are weaker with alkali metal cations. Transition metal cations and Pb2+ interact strongly with the ligands. In particular, Fe3+, Hg2+ and Pb2+ cause greater than 99% quenching of the dansyl fluorescence. 相似文献
47.
Ümmühan Ocak Miraç Ocak Aysel Başoğlu Semanur Parlayan Hakan Alp Halit Kantekin 《Journal of inclusion phenomena and macrocyclic chemistry》2010,67(1-2):19-27
Two crown ethers carrying pyrene side arms with nitrogen-sulfur donor atom were designed and synthesized by the reaction of the corresponding macrocyclic compounds and 1-bromomethyl-pyrene. The influence of metal cations such as Al3+, Zn2+, Fe2+, Fe3+, Co2+, Ni2+, Mn2+, Cu2+, Cd2+, Hg2+ and Pb2+ on the spectroscopic properties of the ligands was investigated in acetonitrile-tetrahydrofuran (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Al3+, Zn2+, Fe2+, Ni2+, Cu2+, and Pb2+ with 16-membered crown ether. Similar results were obtained for Al3+, Fe2+, Hg2+, Cu2+ and Pb2+ with 14-membered crown ether. The results of spectrophotometric titration experiments disclosed the complexation stoichiometry and complex stability constants of the novel ligands with these cations. According to spectrofluorimetric titration measurements the 14-membered diazadithia crown ether showed sensitivity for Pb2+ with linear range and detection limit of 1.3 × 10?6 to 5.2 × 10?5 M and 5.2 × 10?7 M, respectively. The 16-membered diazadithia crown ether showed sensitivity for Ni2+ with linear range and detection limit of 1.3 × 10?7 to 5.2 × 10?6 M and 4.1 × 10?8 M, respectively. 相似文献
48.
The article depicts a detailed study regarding copper selective chemosensing and complexation nature of 5,11,17,23-tetrakis[(N,N-diphenylamino)methyl]-25,26,27,28-tetrahydroxycalix[4]arene (PAC4). Its photophysical characteristics in various solvents of different polarities along with the influence of acid and base on its spectral properties in these solvents are also discussed. The complexation affinity of PAC4 with regard to its latent applications as Cu(II) selective colorimetric and fluorescent sensor among the selected series of various cations such as Li(I), Na(I), K(I), Rb(I), Ba(II), Sr(II), Al(III), Fe(III), Cd(II), Co(II), Hg(II), Mn(II), Ni(II), Pb(II) and Zn(II) was examined by UV–visible and fluorescence emission spectroscopy in dichloromethane:acetonitrile (DCM:MeCN) solvent system. In addition, the process of complexation has been investigated through Job's plot and it has been observed that the complex between PAC4 and Cu(II) is formed in 1:1 stoichiometric ratio. The complex formation between PAC4 and Cu(II) has also been confirmed by FT-IR spectroscopy and thermal gravimetric analysis (TGA). 相似文献
49.
Ümmühan Ocak Miraç Ocak Semanur Parlayan Aysel Başoğlu Yasemin Çağlar Zekeriyya Bahadır 《Journal of luminescence》2011,131(4):808-814
A series of crown ethers carrying a pyrene group with nitrogen–sulfur donor atoms, that differ in having three, four and five sulfur atoms in the macrocycle was designed and synthesized by the reaction of the corresponding macrocyclic compound and 1-bromomethylpyrene. The influence of metal cations such as Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ and Al3+ on the spectroscopic properties of the ligands was investigated in acetonitrile–dichloromethane (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+. The results of spectrophotometric titration experiments disclosed the complexation compositions and complex stability constants of the novel ligands with Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+ cations. The monoazatetrathia crown ether showed good sensitivity for Cu2+ with linearity in the range 5.0×10?7–2.5×10?6 M and detection limit of 1.6×10?8 M. 相似文献
50.
ümmühan Ocak Mira? Ocak Xin Shen Kazimierz Surowiec Richard A. Bartsch 《Journal of fluorescence》2009,19(6):997-1008
A series of three di-ionizable calix[4]arenes with two pendant dansyl (1-dimethylaminonaphthalene-5-sulfonyl) groups linked
to the lower rims was synthesized. Structures of the three ligands were identical except for the length of the spacers which
connected the two dansyl groups to the calix[4]arene scaffold. Following conversion of the ligands into their di-ionized di(tetramethylammonium)
salts, absorption and emission spectrophotometry were utilized to probe the influence of metal cation (Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, Sr2+, Ba2+, Ag+, Cd2+, Co2+, Fe2+, Hg2+, Mn2+, Pb2+, Zn2+ and Fe3+) complexation in acetonitrile. Upon complexation with these metal cations, emission spectra underwent marked red shifts and
quenching of the dansyl group fluorescence for the di-ionized ligand with the shortest spacer. A similar effect was noted
for the di-ionized ligand with an intermediate spacer for all of the metal ions, except Ba2+. For the di-ionized ligand with the longest spacer, the metal cations showed different effects on the emission spectrum.
Li+, Mg2+, Ca2+ and Ba2+ caused enhancement of emission intensity with a red shift. Other metal cations produce quenching with red shifts in the emission
spectra. Transition metal cations interacted strongly with all three di-ionized ligands. In particular, Fe3+ and Hg2+ caused greater than 99% quenching of the dansyl fluorescence in the di-ionized ligands. 相似文献