form a wide range of soft particle and soft-hard particle nanocompounds and
assemblies. Both the nano-elements and their nanocompounds are widely recognized to exhibit new emerging properties and nano-periodic property patterns
[137, 138]. Leading references to these literature examples (designated by X in
the combinatorial nanocompound library in Fig. 24) are described in greater detail
elsewhere [137]. This account will focus only on several selected examples of
nanocompound formation (designated by an asterisk in Fig. 24 ) that involve either
chemical reactions or supramolecular, self-assembly interactions between
dendrons/dendrimers and/or other nano-element categories. For example, selfassembling certain [S-1]-type amphiphilic dendrons, according to Percec and
colleagues. [169], produces vast libraries of stoichiometric spherical or cylindrical
supramolecular dendrimers [S-1] n .
These assemblies may be viewed as nanocompounds/assemblies of the
[S-1]-type nano-element category, much as S 8 is viewed to be a molecular compound of the atomic element sulfur. Combining dendrimers with other dendrimers
has produced core–shell tecto(dendrimers), i.e., [S-1:(S-1)n]-type core–shell
nanocompounds with well-defined stoichiometries. Similarly, covalent grafting of
linear poly(ethyleneglycol)s produces discrete [S-1:(S-3)n]-type core–shell compounds . On the other hand, covalent attachment of fullerenes produced precise
[S-1:(H-4)n]-type core–shell structures. Combining dendrimers with metal
nanoclusters has produced a variety of unique, i.e., [(H-1)n:(S-1)] and [(S-1):
(H-1)n], core–shell-type nanocompounds, as designated in Fig. 24. Specific literature examples of these proposed nanocompounds/assemblies will be described in
the remaining sections of this review.
6.4.2 (Dendrons) n [S-1] n : Self-Assembly into Supramolecular
Spherical or Cylindrical Dendrimer-Type Nanocompounds
and Nano-assemblies
Perhaps some of the most compelling examples of precise stoichiometric [S-1]-type
nano-assemblies are the enormous libraries of spherical and cylindrical supramolecular dendrimers (i.e., supramolecular megamers) reported by Percec and colleagues [151, 169, 170]. Percec’s amphiphilic dendrons have been shown to exhibit
heuristic atom mimicry features reminiscent of atomic elements, namely, precise
mass-combining ratios and unique emerging properties. Just as atomic elements
such as phosphorous and sulfur aggregate into discrete P 4 and S 8 clusters, respectively [171], so do appropriately functionalized Percec dendrons (Fig. 25). Whereas
earlier Zimmerman-type dendron self-assemblies [172, 173] have generally
involved small, single-digit aggregation numbers, many of Percec’s dendrons
self-assemble into supramolecular dendrimers requiring large double-digit aggregation numbers. For example, the number of dendrons leading to hollow, spherical
supramolecular dendrimers involved aggregation numbers of 72–155
[170]. Recently, a remarkably large supramolecular dendrimer derived from
Twenty-First Century Polymer Science After Staudinger: The Emergence of. . .
365
assemblies. Both the nano-elements and their nanocompounds are widely recognized to exhibit new emerging properties and nano-periodic property patterns
[137, 138]. Leading references to these literature examples (designated by X in
the combinatorial nanocompound library in Fig. 24) are described in greater detail
elsewhere [137]. This account will focus only on several selected examples of
nanocompound formation (designated by an asterisk in Fig. 24 ) that involve either
chemical reactions or supramolecular, self-assembly interactions between
dendrons/dendrimers and/or other nano-element categories. For example, selfassembling certain [S-1]-type amphiphilic dendrons, according to Percec and
colleagues. [169], produces vast libraries of stoichiometric spherical or cylindrical
supramolecular dendrimers [S-1] n .
These assemblies may be viewed as nanocompounds/assemblies of the
[S-1]-type nano-element category, much as S 8 is viewed to be a molecular compound of the atomic element sulfur. Combining dendrimers with other dendrimers
has produced core–shell tecto(dendrimers), i.e., [S-1:(S-1)n]-type core–shell
nanocompounds with well-defined stoichiometries. Similarly, covalent grafting of
linear poly(ethyleneglycol)s produces discrete [S-1:(S-3)n]-type core–shell compounds . On the other hand, covalent attachment of fullerenes produced precise
[S-1:(H-4)n]-type core–shell structures. Combining dendrimers with metal
nanoclusters has produced a variety of unique, i.e., [(H-1)n:(S-1)] and [(S-1):
(H-1)n], core–shell-type nanocompounds, as designated in Fig. 24. Specific literature examples of these proposed nanocompounds/assemblies will be described in
the remaining sections of this review.
6.4.2 (Dendrons) n [S-1] n : Self-Assembly into Supramolecular
Spherical or Cylindrical Dendrimer-Type Nanocompounds
and Nano-assemblies
Perhaps some of the most compelling examples of precise stoichiometric [S-1]-type
nano-assemblies are the enormous libraries of spherical and cylindrical supramolecular dendrimers (i.e., supramolecular megamers) reported by Percec and colleagues [151, 169, 170]. Percec’s amphiphilic dendrons have been shown to exhibit
heuristic atom mimicry features reminiscent of atomic elements, namely, precise
mass-combining ratios and unique emerging properties. Just as atomic elements
such as phosphorous and sulfur aggregate into discrete P 4 and S 8 clusters, respectively [171], so do appropriately functionalized Percec dendrons (Fig. 25). Whereas
earlier Zimmerman-type dendron self-assemblies [172, 173] have generally
involved small, single-digit aggregation numbers, many of Percec’s dendrons
self-assemble into supramolecular dendrimers requiring large double-digit aggregation numbers. For example, the number of dendrons leading to hollow, spherical
supramolecular dendrimers involved aggregation numbers of 72–155
[170]. Recently, a remarkably large supramolecular dendrimer derived from
Twenty-First Century Polymer Science After Staudinger: The Emergence of. . .
365