The core shell hybrid dendrimers consisting of a third generation poly(propylene imine) (PPI) dendrimer as a core and poly(benzyl ether) (PBE) dendrons as shells were synthesized. Fine tuning of the nanovoids of the hybrid dendrimers was achieved by changing the generation of the PBE dendron units, which allows the maximum size of Pd clusters encapsulated within the dendrimer to be controlled.