Towards a light driven molecular assembler

Chemists usually synthesize molecules using stochastic bond-forming collisions of the reactant molecules in solution. Nature follows a different strategy in biochemical synthesis. The majority of biochemical reactions are driven by machine-type protein complexes that bind and position the reactive molecules for selective transformations. Artificial “molecular assemblers” performing “mechanosynthesis” have been proposed as a new paradigm in chemistry and nanofabrication. Here we present a simple non-proteinogenic machine-type molecule which drives the endergonic condensation of vanadate to cyclic tetravanadate using light as the energy source. The system combines selective binding of the reactants, accurate positioning, and active release of the product. Hydrolysis of the product prevents inhibition of further cycles. Our prototypic system demonstrates the prerequisites that are needed to selectively drive an endergonic reaction using an external energy source.