Spherical Cyclophosphazene Dendrimers to the Fifth Generation

摘要

Dendrimers, that is. highly branched functionalized molecules formed by iterative reaction sequences, constitute a definite breakthrough into generations of new materials and are attracting considerable attention in organic, supramolecular, and polymer chemistry. Only few of these macromolecules incorporate main group elements such as silicon, germanium, or phosphorus, and only phosphorus dendrimers having charges within the cascade structure had been described till very recently when two kinds of neutral phosphorus dendrimers were reported concomitantly by Majoral et al. and by our group. Majoral's dendrimers have a structure resembling a cauliflower, with SPC1_3 as the core and possess 46 pentavalent phosphorus atoms and 48 terminal functions (aldehydic groups or phosphorus-chlorine bonds; molecular weight 11268 or 15381). His group is now synthesizing further generations having up to 384 functional groups (molecular weight 94146).