Raman spectra of tetrabromophthalic anhydride and its associated charge‐transfer complex, naphthalene‐tetrabromophthalic anhydride

Abstract

AbstractThe low‐frequency Raman spectra of tetrabromophthalic anhydride (TBPA) and its associated charge‐transfer complex naphthalene‐tetrabromophthalic anhydride (N:TBPA) have been recorded at 300 and 77 K. Nine lattice modes are identified for TBPA, the crystal structure of which is found to be unchanged in the range 300–77 K. On complexation, N:TBPA is observed to have a lowest frequency Raman band at 19 cm−1. Neither of its parent molecules have a Raman band with a lower frequency. The 19 cm−1 mode is assigned to the librational motion of the donor (naphthalene) and acceptor (TBPA) molecules of the complex along their stacking axis.