Poly(ether) dendrons possessing phosphine focal points for stabilization and reduced quenching of luminescent quantum dots

Abstract

Hydroxyl terminated, poly(alkyl ether) dendrons possessing single site phosphine functional groups at their focal points have been synthesized. These single site reactive dendrons are then used in ligand exchange reactions to produce stabilized surface capped CdSe/core CdS-shell quantum dots that exhibit high quantum yield, non-quenching photoluminescence (PL) properties. These enhanced features are in sharp contrast to quantum dots capped with analogous single site thiol functionalized dendrons that exhibit substantially quenched photoluminescence. These new dendron constructions begin with protected pentaerythritol moieties which are used as the initiator core as well as the branch cells. By protecting one of the four hydroxyl groups in the pentaerythritol moiety, the remaining three hydroxyl groups are utilized as divergent growth sites for the poly(ether) dendron construction. Desired generation levels (i.e., generations 1, 2) are synthesized, followed by deprotection of the focal point hydroxyl group to expose appropriate functional groups suitable for conversion to sulfhydryl, phosphine or other desired functional groups.