The Raman spectra of the compounds NaCl. ALCL₃ and NOCl. ALCL₃

Abstract

Abstract The Raman frequency shifts and the depolarization ratio of the Raman lines have been determined for the compounds NaCl. AlCl 3 and NOCl. AlCl 3 (in the last case with qualitative polarization measurements only). The preparation of pure NOCl. AlCl 3 is described in extenso. The properties of the compound finally obtained are different from those given in the literature. NaCl. AlCl 3 , has to be considered as Na + AlCl 4 − , and NOCl. AlCl 3 as NO + AlCl 4 − . There is a perceptible interaction between nitrosyl and the chlorines of AlCl 4 − in the last compound. The properties of NOCl. AlCl 3 are intermediate between those for a pure heteropolar compound (NO + AlCl 4 − ) and a pure molecular compound NOCl. AlCl 3 , being more alike those of the heteropolar form. Force constants have been calculated for AlCl 4; − , making use of the Lechner formulae and of those for a Urey‐Bradley field and also of those for the orbital valence force field of Heath and Linnett .