Molecular spectra and structure of selenophen

Infrared study of the C—H stretching region of five-membered heterocyclic compounds

“…The assignments of the C-H stretchings of selenophene are well established from previous studies (21,22). Recently, we reported the ir spectrum and molecular dynamics of selenopbene in the solid state (23).…”

“…Since the first two lines are polarised whereas the latter is depolarised (21), the assignment is straightforward, considering also that the correspondence with the ir gas spectrum gives two A-type bands at 3120 and 3083 cm-l, and a B-type band at 3062 cm-l. The absorption at 3030 cm-' (type-A contour) is the first overtone of the v14 ring stretching (21)(22)(23). In the solid-state ir spectrum there are two doublets a t 3099-3103 and at 3067-3064 cm-' with sharp perpendicular polarisation, and a third doublet at 3052,3054 cm-' with opposite polarisation.…”

“…This is due to a number of factors: (i) four fundamentals (two Al and two B2) must be assigned, but only two sharp peaks are usually observed both in the infrared and in the Raman spectra; (ii) the band profiles of the gas spectra are not well defined, especially in the case of pyrrole and furan; (iii) the Raman polarisation data are scanty and seem to be reliable only for thiophene (14) and selenophene (21).…”

“…Although the vibrational spectra of pyrrole (1-7), furan (6)(7)(8)(9)(10)(11)24), thiophene (6,10,(12)(13)(14)(15)(16)(17)(18), and selenophene (19)(20)(21)(22)(23) have been extensively investigated, considerable discrepancies in the assignment of the 3200-3000 cm-I region exist. This is due to a number of factors: (i) four fundamentals (two Al and two B2) must be assigned, but only two sharp peaks are usually observed both in the infrared and in the Raman spectra; (ii) the band profiles of the gas spectra are not well defined, especially in the case of pyrrole and furan; (iii) the Raman polarisation data are scanty and seem to be reliable only for thiophene (14) and selenophene (21).…”

Chemical vapour deposition of selenium and tellurium films by UV laser photolysis of selenophene and tellurophene

“…The UV absorption spectrum of gaseous selenophene 12 shows an absorption band at 193 nm and continuous absorption between 210 and 260 nm, and that of gaseous tellurophene consists of three major bands at 196, 220 and 275 nm (Fig. 1).…”