To create a situation when the environment of an OCC changes more drastically upon isomerization, we consider the AB scaffold with both phenyl rings functionalized in the para position with the CaO-moieties (bpAB), as shown in Fig. . In contrast to the isomerization of pAB, where the CaO-group did not sense large changes to its chemical environment, isomerization of bpAB changes the distance between two polar CaO-groups. The optimized geometries of the two isomers show that the structure of the CaO-moieties is preserved, meaning that the interactions between the two OCCs are weak and do not induce changes in the overall bonding pattern. The excitation energy from the ground state to the first exited state is shifted; this is an expected outcome related to the change in the electron withdrawing strength of the ligand.