Electronic-Structure Calculations and Determination of Thermodynamic Values. Groundand excited state optimizations and vertical excitation energies were performed using Gaussian 16 suite of programs. Spin-orbit coupling constants (SOCs) and excited state absorption spectra were calculated with ORCA 4.2.1. Implicit solvation effects were modeled in Gaussian 16 or in ORCA 4.2.1 using the integral equation formalism of the polarizable continuum model (IEFPCM) or the conductor-like polarizable continuum model (CPCM), respectively.