Chemistry Reference
In-Depth Information
FIGURE 1.5
4.5); {dendri-poly(amidoamine)-(CO
2
Me)
Z
}; (PAMAM)
dendrimers. A 3-D projection of such a dendrimer core-shell architecture for G
¼
4.5 poly
(amidoamine) (PAMAM) dendrimer with principal architectural components (I) core, (II)
interior, and (III) surface [20].
Tomalia type (G
¼
generations added; whereas, the terminal functional groups increase exponentially
(Figure 1.8) as a function of generation. This dilemma enhances “tethered con-
gestion” of the anchored dendrons, as a function of generation, due to the steric
crowding of the end groups. As a consequence, lower generations are generally open,
floppy structures; whereas, higher generations become robust, less deformable
spheroids, ellipsoids, or cylinders [23] depending on the shape and multiplicity of
the core.
1.3 EXPERIMENTALLY PROVEN STRUCTURAL CONTROL OF
CRITICAL NANOSCALE DESIGN PARAMETERS (CNDPs)
In this section, we focus on experimentally proven examples that illustrate structural
control of CNDP's when synthesizing dendrons/dendrimers. This brief overview
illustrates examples of atom mimicry based on the synthetic ability to control;
(a) sizes, (b) shapes, (c) surface chemistry, (d) flexibility, and (e) architecture at the
nanoscale level. It is apparent, that both the core multiplicity (N
c
) and branch-cell
multiplicity (N
b
) determine the precise number of terminal groups (Z) and mass
amplification as a function of generation (G). One may view those generation
sequences as quantized polymerization events that adhere to the dendritic aufbau
