| The novel synthesis of p-phenylene vinylene dendrons utilizing a Horner-Wadsworth-Emmons based approach is described. The extended, linear pi conjugation along all the dendron branches, a feature absent in most dendrimers used for light harvesting, was expected to lead to an efficient light-harvesting system by acting as a dendritic molecular wire between peripheral donor chromophores and a core acceptor. To that end, nickel porphyrins were added to the periphery of the dendrons as preparation for inclusion in dye-sensitized solar cells. The prepared dendron-porphyrin conjugates proved to be poor dyes. This disappointing result is attributed to the use of nickel porphyrins which were found to undergo non-radiative decay, making them unsuitable for light-harvesting applications. Changes to the system are proposed, from replacing the nickel with zinc within the porphyrins to the use of alternative chromophores, to better test the dendrons function as molecular wires. |
