title: Bimolecular catalysis and turnover from a macromolecular host system.
abstract: The synthesis of a globular macromolecule and its application as a bimolecular catalyst are reported. The macromolecular structure supports (at least) two zinc-metalated porphyrin units, each capable of binding a single reactant. The proximity of the two bound reactants results in an increased local concentration, leading to a maximum 300-fold increase in the reaction rate. In contrast to other synthetic catalysts, where bidentate products inhibit further reactions, this macromolecular system allows the product to be displaced by the reactants leading to turnover and catalysis. We believe that this is due to the dynamics of the macromolecular host system, which maintains enough flexibility to adopt a favorable/reactive geometry, which allows the reactants to get close and react while possessing sufficient rigidity/poor geometry to reduce and disrupt any cooperative/inhibitive bidentate binding.
authors.affiliation: Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Ellis
authors.forename: David
authors.initials: D
authors.lastname: Gooch
authors.forename: Lance J
authors.initials: LJ
authors.lastname: Twyman
mesh_terms: D002384:Catalysis; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry*; D008665:Metalloporphyrins / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D015032:Zinc / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D008665:Metalloporphyrins; D015032:Zinc