THERMAL-ANALYSIS OF THIONE COMPOUNDS .1. THE THERMAL-BEHAVIOR OF THIOUREA AND N-METHYLTHIOUREAS

The thermal behavior of thiourea (Tu), N-methylthiourea (MeTu), N, N'- dimethylthiourea (Me2Tu) and N, N, N', N'-tetramethylthiourea (Me4Tu) was investigated by means of conventional thermal analysis in O2 and N 2 and IR spectroscopy of the residues on heating in air at various tem peratures. At ordinary pressure, the compounds are thermally stable up to the melting points. After melting, they show high vapor pressure, combustion in O2 atmosphere and isomerization to ammonium thiocyanate, with the exception of Me4Tu.