Chemistry Reference
In-Depth Information
the years passed by we began taking the time to make them more aesthetically
appealing, paying attention to details like size, shape, shading, and intelligibility
above all else. The result is that our cartoons - and graphical representations more
generally - have gone through an evolutionary process of their own (represented
chronologically in Fig.
17
), which was more or less at the point it is today by the
year 2000. Two-dimensional cartoons were displaced progressively by three-
dimensional ones, which inherently aid in the visualization of molecular stereo-
chemistry by their portrayal of perspective. Our first 3D cartoon was a branched
heptacatenane (Fig.
17
), which was illustrated directly below the space-filling
representation of the solid-state structure (Fig.
14b
) in the original paper [
84
]in
1997. A comparison between the two modes of depiction makes it immediately
obvious why there is utility in such cartoons; they do justice to the topology as well
as the Euclidean shape of the molecule!
Fig.
18
presents a summary of the different ways to represent the same catenane.
It is apparent that venturing into cartoons has opened space for much more freedom
and creativity in the representation of molecules (note that every type of cartoon in
Fig.
18e
has been published in the chemical literature). We conclude that the
transition to cartoons has been a boon in the field because cartoons:
1. Highlight topology by de-emphasizing atom and bond details
2. Allow for the denotation of features that structural diagrams and formulas lack
(e.g., noncovalent bonding interactions)
a
b
c
d
Line drawing
Structural formula
Structural diagram
Crystal structure
e
Cartoons
Fig. 18 Different representations of the same donor-acceptor [2]catenane. Line drawings (a) and
condensed structural formulas (b) were the order of the day until the modern era of MIMs gave
way to structural diagrams (c) and crystal structures (d). Graphical representations, also called
cartoons (e), can be a helpful compromise between these representations when attempting to
emphasize the topology, noncovalent bonding interactions, shape, beauty, or function of a MIM
