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化学   2篇
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The charge transfer complexes formed between some anilides and pi-electron acceptors [picric acid, 2,4-dinitrophenol, 3,5-dinitrobenzoic aicd, 3,5-dinitrosalicylic acid and m-dinitrobenzene] are synthesized and characterized. Spectral characteristics and stability of the complexes are investigated and discussed in terms of donor molecular structure, pi-acceptor electron affinity, and solvent polarity. It is deduced that the complexes are mainly of the n-pi* and pi-pi* type where the ground state wave function can be described primarily by the non-bonding structure. The optimum conditions favouring the formation of the coloured complexes are extensively studied for the microdetermina-tion of anilides derivatives in pharmaceutical drugs using nitrobenzene as acceptor; the molecular structure was found to be 1:1 (D:A). Beer's law is obeyed up to 23.0, 18.60 and 16.0 micrograms ml-1 for p(OH), p-(OCH3), and p-N(CH3)2, respectively.  相似文献   
2.
The molecular complexes of some lanthanides scandium (Sc3+), yttrium (Y3+), lanthanum (La3+), gadolinium (Gd3+), cerium (Ce3+) and ytterbium (Yb3) have been studies in dimethyl formamide (DMF) spectrophtometrically equilibrium constants (K), molar extintion coefficient (epsilon), energy of transition (E) and free energy (delta G*) were calculated. The polymerization of acrylonitrile has been studied and investigated in the presence of Sc3+, Y3+, La3+, Gd3+, Ce3+, and Yb3+ ions. The IR spectra of the formed AN-M (III) Br3 polymer complexes show the absence of the C identical to N band and the presence of two new bands corresponding to NH2 and OH groups. Magnetic moment values and the thermal stabilities of homopolymer and the polymer complexes were studied by means of thermogravimetric analysis and the activation energies for degradation were calculated.  相似文献   
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