Nature uses the principles of encapsulation and supramolecular chemistry to bind and orientate substrates within active catalytic sites. Over the years, synthetic chemistry has generated a number of small molecule active site mimics capable of catalysing reactions involving bound substrates. Another approach uses larger molecules that better represent an enzymes globular structure. These molecules mimic an enzymes structure by incorporating binding/catalytic sites within the globular structure of the polymer. As such, the electronic and steric properties around the binding/catalytic site(s) can be controlled and fine-tuned. One class of polymer that is particularly adept at mimicking the globular structure of enzymes are dendritic polymers. This review will concentrate on the use of hyperbranched polymers as synthetic enzyme mimics.

This paper describes the facile synthesis of a hyperbranched poly(aryl ester) that possesses a number of porphyrin units within its globular structure. The simple procedure utilizes commercially available starting materials which after fractionation generate a series of polymers with molecular weights between 4500 and 30 000 Da. The number of porphyrins increased with molecular weight with the largest polymer containing ∼6 porphyrins. Further analysis revealed a linear relationship between the number of incorporated porphyrins and molecular weight.

No abstract

Abstract

This communication describes the use of non-covalent chemistry to construct recyclable porphyrin cored HBPs. The non-covalent design allows the polymeric backbone to be rescued and reused after porphyrin degradation. The steric environment within the polymeric encapsulated ligand notably affected the porphyrin coordination geometry.