Substituted 2,4-Di(pyridin-2-yl)pyrimidine-Based Ruthenium Photosensitizers for Hydrogen Photoevolution under Red Light.

The photocatalytic reduction of water to form hydrogen gas (H) is a promising approach to collect, convert, and store solar energy. Typically, ruthenium tris(bipyridine) and its many derivatives are used as photosensitizers (PSs) in a variety of photocatalytic conditions. The bis(terpyridine) analogues, however, have only recently gained attention for this application because of their poor photophysical properties.