Chemistry Reference
In-Depth Information
FIGURE 1.25
(a) Symmetry properties of core-shell tecto(dendrimer) structures, when:
r
1
/r
2
<
1.20. (b) Sterically induced stoichiometry (SIS) defined shell capacities (N
max
), based on
the respective core and shell radii, when: r
1
/r
2
<
1.20. (c) Mansfield-Tomalia-Rakesh equation
for calculating the maximum shell filling value (capacity) (N
max
), when: r
1
/r
2
>
1.20 [6,55].
mathematically quantized ligation sites present in Yamamoto-type dendrimers, it was
possible to quantitatively document an amazing sequence of metal-dendrimer shell
filling events. These metal-shell filling events are heuristically reminiscent of
traditional electron-shell filling events observed for elemental atoms. It was shown
in this present case that quantized amounts of metal salts will first ligate closest to the
core at the lowest generation level to produce a saturated generational shell with well-
defined and perfect stoichiometry (i.e., 4
1), based on ligation sites present.
Subsequent addition of metal reagent led to a stepwise filling of the next highest
generational shell until it reached a shell-saturated state (i.e., 8
@G
¼
@G
¼
2) and
higher generation saturation states as shown in Figure 1.26.
1.7 FIRST STEPS TOWARD A “CENTRAL DOGMA”
FOR SYNTHETIC NANO-CHEMISTRY? DENDRIMER-BASED
NANO-CHEMISTRY
As stated earlier (Figure 1.1), the “central dogma” for traditional soft matter chemistry
emerged from the first initiatives of Lavoisier and Dalton in the early nineteenth
