A New Approach for Studying Bond Rupture/Closure of a Spiro Benzopyran Photochromic Material: Reactivity Descriptors Derived from Frontier Orbitals and DFT Computed Electrostatic Potential Energy Surface Maps

Figure 4

The molecular electrostatic potential mapped onto total SCF electron density for the different forms of closed SP and merocyanine-like isomer (isovalue for the isosurfaces) with different color codes from −ve value (red) to +ve value (blue) expressed in kJmol⁻¹.