ELECTRONIC STRUCTURE AND SPECTRUM OF SILVER(I)PERCHLORATE-PYRIDINE COMPLEX

The absorption spectrum of the silver perchlorate-pyridine system was measured in acetonitrile and ethanol in the wavelength region of 180 mμ to 400 mμ. It was found that the solution exhibits a new shoulder in the 210 mμ region characteristic for the 1:1 complex, in addition to the absorption maxima at 196 mμ and 253 mμ which correspond, respectively, to the La and Lb bands of pyridine. From the concentration dependence of the absorption intensity of this shoulder, the equilibrium constant for 1:1 complex formation was determined to be 108 l/mole at 26 °C. Furthermore, we studied theoretically the electronic structure of this complex by the method of the localized orbital model, the effect of the solvation energy upon the charge-transfer configurations being taken into account. The theoretical results show that the new absorption band at 207.5 mμ has to considerably great extent the character of a charge-transfer type excitation. © 1968 Springer-Verlag.