Figure 9.

Showing 15Za-18Et-BV chromophore with ZZZssa geometry. Rings A, B, C, and D (from left to right) are marked by red areas; the ring formed by the covalent linkage between rings C and D is marked by a green area. Blue arrows: ν(C₁₉ = O) tdm, red arrows: ν(C₁ = O) tdm. Blue and cyan cones show 1σ range of angle μC₁₉ = O around vibrational tdm of ν(C₁₉ = O); red and pink cones show 1σ range of angle μC₁ = O around vibrational tdm of ν(C₁ = O). Electronic tdm orientation is given by the intersection area of the cones, indicated by orange rectangular and the black arrow. Note that each cone of angle θ has also a cone of angle 180°-θ.