Polyvalent Catalysts Operating on Polyvalent Substrates: A Model for Surface-Controlled Reactivity.

ABSTRACT: Unusually fast rates of nucleophilic catalysis of hydrazone ligation were observed when polyvalent anthranilic acid catalysts operating on polyvalent aldehyde substrates were used with PAMAM dendrimers as the common platform. When presented in this way, the catalyst has a strong accelerating effect at concentrations 40-400 times lower than those required for similar monovalent catalysts and displays unique kinetic parameters. We attribute these properties to polyvalent engagement between the dendrimer surface groups, and a potential "rolling" effect leading to fast interparticle kinetic turnover. The phenomenon is sensitive to the density of functional groups on each dendrimer, and insensitive to factors that promote or inhibit nonspecific particle aggregation. These findings constitute a

SUBMITTER: McKay CS 

PROVIDER: S-EPMC6939865 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature