Studies of the electronic properties of the tetrathiotungstate(VI) ion, [WS4]2–, by low-temperature absorption and resonance Raman spectroscopy
Abstract
The resonance Raman spectrum of the [WS4]2– ion as its [NH4]+ and [NBu4]+ salts has been studied over the range 647.1–350.7 nm. On the basis of the observed ν1(a1) band progressions, values for the harmonic wavenumber (ω1) and anharmonicity constant (x11) are calculated and the bandwidths are discussed in terms of contemporary theories. Computer simulation of the observed excitation profiles of the ν1, 2ν1, and 3ν1, bands in the case of the [NBu4]+ salt allows the deduction that, on excitation from the ground (1A1) to resonant excited (1T2) states, the W–S bond length increases by 0.058 Å.