Effects of metal–metal bonding in photosensitizers: red-shifted absorption and oscillator strength enhancement

Abstract

Metal–metal bonding of known bimetallic photosensitizers featuring Ru–Ru, Mo–Mo, Ag–Ag and Rh–Rh bonds was explored using computational modeling benchmarked by established experimental parameters. The analysis reveals that these metal–metal bonds facilitate (1) a red-shift in the maximum absorption wavelength (λ_max) and (2) an increase in the oscillator strength of the λ_max peak. A statistical analysis also reveals a strong correlation between the metal–metal bond order and the oscillator strength. These trends show that metal–metal bonds play a significant role in enhancing the photophysical properties of photosensitizers and inform future photosensitizer designs.