THE S—S BOND IN N,N'-DITHIOBISAMINES. A RAMAN STUDY

Abstract

The Raman spectra of a series of N,N'-dithiobisamines, (R₂N)₂S₂ and their cyclic analogues compounds, 3,6-dialkyl-1,2,4,5,3,6-tetrathiadiazine have been studied in the 600-300 cm⁻¹ region. Strong and polarized bands in the range 410-450 cm⁻¹ were assigned to the stretching S—S vibration for the non-cyclic NSSN compounds while that in the cyclic 3,6-dibenzyl-1,2,4,5,3,6-tetrathiadiazine this vibration appears in 480 cm⁻¹. The low v(S—S) frequency values for N,N'-dithiobisamines are in agreement with their chemical behaviour. An approximately linear relationship between v(S—S) and the S—S bond length, d(S—S) for N,N'-dithiobisamines and other disulfide compounds is proposed and discussed.

Key Words:

• N,N'-dithiobisamines
• raman spectra
• disulfide compounds
• S—S bond