Vibrational analysis of (SCN)2 and the transient (SCN)2−

The vibrational spectra of thiocyanogen and the transient radical anion (SCN)2− are interpreted in detail through molecular orbital and normal coordinate calculations. The results support the assignment of (SCN)2− to the anion of thiocyanogen and indicate a substantial weakening of the S–S and C≡N bonds in going from the parent molecule to its radical anion.