Chemical Structure from Scientific Research

Simplified state diagram for the extended (ex) and stacked (st) forms ofDAD4, displaying relevant electronic transitions, with the main contributions of the mono-electronic excitations (S1,2: >=98%; S3: >=97%; S6: >=85%) and the corresponding MO topologies (H = HOMO, L = LUMO). The energy difference between the two CS/CT states (S1, S2) is <0.05 eV; the two LE transitions (S3,6) are mainly described by H-a->L and H-b->L, where a= 4,b= 5 for theex-form, and a= 2,b= 5 for thest-form. Geometries optimized with the omegaB97XD functional, electronic states calculated with the PBE0 functional.

DOI