INFRARED SPECTRA OF ADDITION COMPOUNDS OF CYANOGEN HALIDES WITH SOME INORGANIC HALIDES

The infrared spectra of addition compounds of cyanogen halides (ClCN, BrCN) with inorganic halides (SbCl 5, TiCl4, AlCl3, AlBr3) have been measured in the region from 4000 to 250 cm-1. The displacement of bands by the formation of a co-ordination bond and the appearance of metal-to-nitrogen stretching vibrations indicate the acceptance of a lone pair of electrons from the nitrogen atom of cyanogen halides in virtue of Lewis acid. The bands observed in the addition compounds of cyanogen halides (ClCN, BrCN) with SbCl5 have been assigned on the basis of C4v symmetry, and those with TiCl4 of D4h symmetry. The bands observed in the addition compounds of ClCN with AlCl3 and of BrCN with AlBr3 have been assigned on the basis of C3v symmetry. The displacement of CN stretching frequency has also been studied for the addition compounds of ClCN with inorganic halides (AlCl3, TiCl4) in the solution of SOCl2 or POCl3. © 1969.