Electronic absorption spectrum of methyl allenyl sulfide

The ultraviolet absorption spectrum of methyl allenyl sulfide CH₃SCHCCH₂ was recorded in solution from 30000–50000 cm^?1 in order to inquire further into the role of sulfur 3d valence-shell and 4s Rydberg-type atomic orbitals for the low-lying excited singlet states in unsaturated organic sulfides. It is shown that sulfur 3d atomic orbitals cannot be neglected for the interpretation of the low-energy excited singlet states of unsaturated organic sulfides.