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951.
Patel RN Singh N Shukla KK Gundla VL 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(8):1893-1897
X-band E.S.R., magnetic and electronic spectra of some imidazolate-bridged homometallic complexes [(en)2Cu-R-Im-Cu(en)2](ClO4)3 where en, ethylenediamine; R-ImH, R = H imidazole (ImH); if R = CH3, 2-methylimidazole (M-ImH) and if R = C2H5, 2-ethylimidazole (E-ImH), and mononuclear complexes [(en)Cu-dien](ClO4)2 and [(en)Cu-PMDT](ClO4)2 where dien, diethylenetriamine; PMDT, pentamethyldiethylenetriamine have been described. Superoxide dismutase (SOD) activity has also been measured and compared with earlier reported complexes. In frozen solution at 77 K, the spectra show axial symmetry with a d(x2-y2) ground state. Difference in lambda(max) between mononuclear and binuclear complexes was found to be approximately 65-75 nm. Magnetic susceptibility and E.S.R. spectral measurements for all these binuclear complexes revealed that the copper(II) ions are involved in antiferromagnetic exchange interactions propagated by the imidazolate bridge. 相似文献
952.
H S Patel 《Journal of Chemical Sciences》1986,96(5):321-326
Fries rearrangement of 8-acetoxyquinoline-5-aldehyde (aqa) in nitrobenzene using AlCl3 as catalyst affords the polychalcone poly(8-hydroxy-5,7-quinolinylenecarbonylvinylene) (phqcv). Thephqcv samples were characterized by elemental analysis,ir spectroscopy, molecular weight, intrinsic viscosity andtga.
Polymeric metal chelates of Cu2+, Fe3+, Co2+, Ni2+, Mn2+, Zn2+ and UO
2
2+
withphqcv polychalcone were prepared and characterized. 相似文献
953.
Dattatraya V. Jahagirdar Nandkumar G. Palaskar Babulal H. Patel 《Transition Metal Chemistry》1989,14(3):213-216
Summary The interactions of CuII witho-hydroxyacetophenone (OHA) and its halogeno- and nitro-substituted derivatives were investigated potentiometrically in dioxane-water mixtures by the Calvin-Bjerrum titration technique at 25° C and ionic strength =0.1 M (NaClO4). All the ligands form 11 and 12 chelates with CuII.The variations of pK with mole fraction of dioxane and 1/D were almost linear. Linearity was observed in the plots of log K1/logK2
versus pK, and the magnitudes of slopes led to the conclusion that -donation is: (i) strong in aqueous medium and decreases with the increase in dioxane content in 11 chelates, and (ii) weak and does not change with dioxane, in 12 chelates. 相似文献
954.
The reactions of mixtures of halogen atoms (F + (Cl or Br)) with molecular azides produce banded emissions in the visible and near-infrared regions of the spectrum. The observed features correspond to b1Σ+ → X3Σ? and a1Δ → X3Σ? transitions, respectively, in NCl and NBr. The data obtained represent the first spectroscopic observation of the a1Δ states of these molecules. The molecular constants of the a1Δ states were determined to have the following values:
NCl | NBr | |
9260 ± 10 cm?1 | 9226 ± 10 cm?1 | |
904 ± 6 cm?1 | 763 ± 4 cm?1 | |
4.7 ± 1.2 cm?1 | 2.4 ± 1.6 cm?1 |