Electronic states and spectra of BiTe

NIR/VIS emission spectra of the bismuth telluride radical, BiTe, were measured in the 3600-20 000 cm−1 region with a Fourier-transform spectrometer. BiTe was produced by reaction of bismuth and tellurium vapors and excited by energy transfer from metastable oxygen O2(a1Δg) in a fast-flow system. The spectrum of BiTe was found to be markedly different from those of the previously studied BiO, BiS and BiSe radicals. The A24Π1/2 → X12Π1/2 transition which forms the most prominent and extended band system in these molecules was not observed for BiTe, and the X22Π3/2 → X12Π1/2 fine structure transition shows up with a different structure and at much lower wavenumbers than in the spectra of the lighter bismuth chalcogenides. The only common feature is the C14Σ−1/2 → X12Π1/2 system which is found in the range 16 500-19 000 cm−1 similar to the three other molecules. Besides the X2 → X1 and C1 → X1 systems, seven other transitions show up by short Δν = 0 sequences only. With help of the data derived from the analyses of the X2 → X1 and C1 → X1 systems and theoretical predictions of electronic and vibrational energies and transition probabilities of the strongest transitions of BiTe by Lingott et al. [7] the spectra were assigned to the transitions C14Σ−1/2 → X22Π3/2, C14Σ−1/2 → A24Π1/2, A44Π1/2 → A24Π1/2, A44Π1/2 → X22Π3/2, B12Π1/2 → A24Π1/2, B12Π1/2 → A14Π3/2, and B22Π3/2 → X22Π3/2.