FAR INFRARED INTENSITY STUDIES ON CHARGE TRANSFER COMPLEXES OF IODINE AND IODINE MONOCHLORIDE

Abstract

Financial support from Public Health Service Research Grant No. GM-10168 from the Division of General Medicine, PHS, is gratefully acknowledged. $^{1}$ W. B. Person, R. E. Humphrey, W. A. Deskin and A. I. Popov, J. Am. Chem, Soc. 80, 2049 (1958). $^{2}$ W. B. Person, R. E. Humphrey and A. I. Popov, J. Am Chem. Soc. 81, 273 (1959). $^{3}$ W. B. Person, R. E. Erickson and R. E. Buckles, J. Am. Chem. Soc. 82, 29 (1960). $^{4}$ H. B. Friedrich and W. B. Person, J. Chem. Phys. 44, 2161 (1966).Author Institution: Department of Chemistry, University of IowaThe infrared intensities of the $\nu(I-CI), \nu(I-I)$ and $\nu (D-A)$ vibrational bands found in charge-transfer complexes of n and $\pi$ electron donors with $I_{2}$ and ICl have been measured in benzene and n-heptane solutions. A Beckman IR-11 spectrometer was used together with a cell constructed of high density polyethylene. Pathlength calibrations have been carried out using bands of known intensity in pure liquid $CHCl_{2} CCl_{4}$ and benzene, and it has been shown that the pathlength variation when using such a cell is sufficiently small to give good Beers Law plots and intensity values with a random error of less than $\pm 12$. The results extend the $earlier^{1-2}$ higher frequency intensity studies on complexes with $Br_{2}, ICl$ and ICN. Quantitative confirmation that the intensity of the $\nu(N-I)$ vibration is significantly lower than that of the $\nu (I-Cl)$ vibration in the pyridine-ICl complex has been obtained, indicating a smaller vibronic $effect^{4}$ in the former vibration