Dendrons, coordinating focal point

PBE dendrons coordinate to the surface of II-VI semiconductor nanocrystals (e.g., CdSe [33] and CdSe/ZnS core/shell structure [34, 35]) to modulate the photoluminescence of the nanocrystals [32]. Trioctylphosphine oxide (TOPO)-capped II-VI semiconductor nanocrystals of several-nanometers diameter have been synthesized by a pyrolysis reaction of organometallics in TOPO [33-35]. The capping ligand (TOPO) can be replaced by stronger ligands such as thiol compounds [36], suggesting that dendrons bearing sulfur atom(s) at the focal point replace TOPO as well. 

Frechet et al. were able to coordinate polyether dendrons having carboxylate functional groups at the focal point with lanthanide ions up to the fourth generation (Fig. 2.11) [41]. Preparation by straightforward ligand exchange starting from lanthanide triacetates with dendron carboxylates was made possible by the... 

Frdchet and coworkers [314] have recently described a similar self-assembly of benzyl ether dendrons, possessing carboxylic acid substituents at their focal points by metal-ligand coordination around a core of trivalent lanthanide metals (e.g., Er+, Eu", or Tb+ ). These self-assembled dendrimers were isolated by using ligand exchange reactions to produce structures derived from metal-ligand ionic interactions as shown in Figure 12. As a consequence,... 

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