Vibrational spectra and raman intensity of N(CH3)(4)[CdCu(CN)(4)]center dot CCl4 clathrate

The Raman and infrared spectra of N(CH3)(4)[CdCu(CN)(4)]. CCl4 are reported , revealing back-donation of the d electrons of Cu+ ions to C=N bonds, a Ra man intensity change, especially in the nu(2) mode of CCl4, and the existen ce of strong host modes at 170 and 143 cm(-1). A normal coordinate analysis was carried out, confirming the assignments and deducing the force constan ts. The Raman intensity was analyzed using the modified many-body model, gi ving rise to good agreement with observations, The weakness of nu(2) of CCl 4 in the Raman intensity is explained numerically in terms of a large pertu rbation to the induced dipolar interactions between non-bonded chlorine ato ms from the host lattice. The strong host lattice modes at 170 and 143 cm(- 1) result mainly from the asymmetry of the Cu-CN-Cd skeleton. Copyright (C) 1999 John Wiley & Sons, Ltd.