Photoinduced Charge Transfer in Porphyrin–Cobaloxime and Corrole–Cobaloxime Hybrids

Citations Over TimeTop 10% of 2012 papers

Abstract

We report on the synthesis of hybrid molecules consisting of a porphyrin or corrole chromophore axially coordinated to a [CoIII(dmgH)2(Cl)]±0 (dmg = dimethylglyoxime) unit via a pyridine group as potential hydrogen forming entities in H2O/THF medium. Photophysical, electrochemical, and pulse radiolysis studies on the hybrids and/or their separate components show that selective excitation of the porphyrin or corrole chromophore in its first singlet excited state leads to fast charge separation due to chromophore to cobalt electron transfer. However, this charge separation is followed by even faster charge recombination thereby preventing the accumulation of a reduced cobalt species which would lead to hydrogen production. It is important, nevertheless, that addition of a sacrificial electron donor slows the charge recombination down. In light of the latter it comes as hardly surprising that the photocatalysis experiments in the presence of a sacrificial electron donor (i.e., triethylamine) show modest rates of hydrogen production.

Related Papers

• → Photoinduced Charge Transfer in Porphyrin–Cobaloxime and Corrole–Cobaloxime Hybrids(2012)64 cited
• → TTF–porphyrin dyads as novel photoinduced electron transfer systems(2003)42 cited
• → Intramolecular photochemical electron transfer to acceptors in a β-cyclodextrin linked to a porphyrin(1984)39 cited
• → Photophysical characterization of a bisacridinium-diphenylporphyrin conjugate(2023)2 cited
• → Efficient light activation of a [Ru(bpy)(tpy)Cl]+ catalyst by a porphyrin photosensitizer at small driving force(2020)