RAMAN-SPECTRUM OF POTASSIUM TETRACYANOQUINODIMETHANE CRYSTALS

The Raman spectrum of K(TCNQ) crystals has been obtained from 30 to 2300 cm-1. We have identified lattice modes at 70, 81, 110, 170, 229, and 295 (±5) cm-1 and 13 intramolecular modes above 300 cm-1. The modes at 70, 81, and 110 cm-1 are probably (TCNQ)- librations. The intensity of the lattice modes is independent of the laser-field orientation, indicating isotropy for the nuclear motions, but the intramolecular modes are more intense when the laser field is directed perpendicularly to the crystal axis, indicating the stacking arrangement for the TCNQ's. © 1979 The American Physical Society.