Spectroscopic study of the complexation of 18-crown-6 with iodine, iodine monobromide and bromanil in chloroform
2007
Refar, M.S., Suez Canal Univ., Port Said (Egypt). Faculty of Education. Dept. of Chemistry | Khater, H.M., Zagazig University (Egypt). Faculty of Science. Dept. of Chemistry | Sadeek, S.A., Zagazig University (Egypt). Faculty of Science. Dept. of Chemistry
Spectrophotometric study was performed on the formation of charge-transfer (CT) complexes between 18-crown-6 and sigma-acceptors such as iodine, iodine monobromide (IBr) and pi-acceptor (omicron-bromanil, BRL) in chloroform at 25 deg C. The 1:1 modified. Benesi-Hildebrand method was applied to the determination of association constant (K), moral absorptivity (epsilon), dipole moment (mu), oscillator frequency (f) and ionization potential (Ip). The solid CT complexes have been synthesized and characterized by different spectral methods. The changes in the spectra reveal that the CT interaction depends on the type of the acceptors. Raman and far infrared spectra were taken to interpret the presence of the I3E- ion in the 18-crown ether-6 iodine complex, [(18-crown-6)2]I+.I3E-. The absorption bands at 155, 103 and and cmE-1 are assigned to the three vibrations of the triiodide ion, the asymmetric stretching vibrations nuas(I-I); I3E-, symmetrical stretching vibrations nus(I-I; I3E- and bending vibrations sigma (I3E ), respectively.
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