Stability-enhanced hydrogen-evolving dirhodium photocatalysts through ligand modification.

The two-electron mixed-valent complex Rh(2)(0,II)(tfepma)(2)(CN(t)Bu)(2)Cl(2) (tfepma = CH(3)N[P(OCH(2)CF(3))(2)](2)) photocatalytically splits HCl to generate H(2). Whereas this catalyst degrades rapidly, with H(2) production ceasing after about 36 hours (3 turnovers), a modified complex, Rh(2)(0,II)(tfepma)(2)(CNAd)(2)Cl(2) (CNAd = 1-adamantylisocyanide) displays enhanced stability with sustained H(2) production continuing for >144 h (7 turnovers).