AbstractWell-resolved IR and Raman spectra of the two sets of all 10 isomeric complexes [Os(NCS)n(SCN)6-n]3-/2-, n = 0-6, have been recorded. For both series, νCS(N) > νCS(S) and δNCS > δSCN; for the Os(III) complexes, vCN(N) ~ vCN(S) and vOsN ≥ vOsS while for the Os(IV) compounds, vCN(N) < vCN(S) and vOsN ~ vOsS. The vibrational spectra of the n = 0 and n = 6 members of both sets are assigned according to D3d and Oh point symmetry, respectively. For the mixed linkage isomers the band pattern is strongly influenced by pseudo-octahedral coupling wherever frequencies of N- and S-bonded groups coincide. The metal-ligand stretching region is therefore assigned according rather to pseudo-Oh, pseudo-D3d and pseudo-D4h symmetry than to D4h, C4v, C3v and C2v microsymmetry. The charge-transfer spectra of both series are similar, showing a parallel hypsochromic shift with increasing n value. Upon oxidation, a bathochromic shift of the CT bands by an average of 5400 cm-1 is observed, and the intensity increases by a factor 2-2.5. Weak absorptions in the near infrared region are assigned to intraconfigurational transitions.
Pressure-dependent interfacial charge transfer excitons in WSe2-MoSe2 heterostructures in near infrared region
