Aluminium pyridyl porphyrins. Versatile platforms for self assembling of electron transfer photosystems

Towards the design of artificial photosystems, non-covalent self-assembling strategies exhibit several attractive features: mild conditions, combinatorial flexibility, repair capability. Their application to intrinsically non-symmetric systems is not obvious, however. We have recently described the spontaneous self-assembly of a triad for photoinduced charge separation based on a bifunctional Aluminium pyridylporphyrin platform [1]. There, the Lewis acid and basic functions (metal center and meso-pyridyl group) were used to bind, respectively, electron acceptor and donor units. We are now working to extend such type of strategy for the assembling of systems forphotocatalytic hydrogen evolution. For instance, on the same platform, complex units with hydrogen evolving catalytic activity could be coordinated via the meso-pyridyl group. On the other hand, axial coordination at the Al center can be exploited to reversibly bind a variety of sacrificial electron donors containing carboxylic functions.