Conformational analysis through selective isotopic substitution: supersonic jet spectroscopic determination of the minimum energy conformation of o-xylene

Abstract

Supersonic jet mass resolved excitation spectroscopy is employed to observe the S₁â†� S₀ electronic transition origin of the individual conformations of [α-²H₁]-, [α,α-²H₂]- and [α,α′-²H₂]-o-xylene and to establish the minimum energy conformation of o-xylene in its ground (S₀) and first excited (S₁) singlet states. The anti, planar, gear clashed conformer 5[see Tables 1 and 2; i.e., τ(C-2–C–1-Cα–H-α)=τ(C-1–C-2–C-α′–H-α′)= 180°] is found to be the most stable.