Rational design of a neutral pH functional and stable organic photocathode.

In this work we lay out design guidelines for catalytically more efficient organic photocathodes achieving stable hydrogen production in neutral pH. We propose an organic photocathode architecture employing a NiO hole selective layer, a PCDTBT:PCBM bulk heterojunction, a compact TiO2 electron selective contact and a RuO2 nanoparticle catalyst. The role of each layer is discussed in terms of durability and function.

Synthesis and Isomeric Analysis of Ru Complexes Bearing Pentadentate Scaffolds.

A Ru-pentadentate polypyridyl complex [Ru(κ-N-bpy2PYMe)Cl] (1, bpy2PYMe = 1-(2-pyridyl)-1,1-bis(6-2,2'-bipyridyl)ethane) and its aqua derivative [Ru(κ-N-bpy2PYMe)(HO)] (2) were synthesized and characterized by experimental and computational methods. In MeOH, 1 exists as two isomers in different proportions, cis (70%) and trans (30%), which are interconverted under thermal and photochemical conditions by a sequence of processes: chlorido decoordination, decoordination/recoordination of a pyridyl group, and chlorido recoordination. Under oxidative conditions in dichloromethane, trans-1 generates a [Ru(κ-N-bpy2PYMe)Cl] intermediate after the exchange of a pyridyl ligand by a Cl counterion, which explains the trans/cis isomerization observed when the system is taken back to Ru(II).