Stepwise Sulfite Reduction on a Dinuclear Ruthenium Complex Leading to Hydrogen Sulfide.

Sulfite reduction by dissimilatory sulfite reductases is a key process in the global sulfur cycle. Sulfite reductases catalyze the 6e reduction of SO to HS using eight protons (SO + 8H + 6e → HS + 3HO). However, detailed research into the reductive conversion of sulfite on transition-metal-based complexes remains unexplored.