as well as transporters. In this context the question arises as to whether it is possible
for chemists/scientists to build up systems with comparable functions that would
allow us to speak of machinery en miniature in Nature and technology. Remarkably,
from aqueous solutions of molybdates under reducing conditions, a huge variety of
interesting structures can be obtained which offer a unique substance library and
show really remarkable functionalities, even the phenomenon of cation transport
through pores and of modelling cell response. These nanoscaled systems emerge
by linking well-defined preformed building blocks under the canopy of self-assembly
processes, which are unique regarding the overwhelming variety obtainable. A textbook example is the generation of the tobacco mosaic virus (TMV) in two phases
[2]. In the first phase, the large protein building blocks are generated using encrypted genetic information and these in the second phase become linked to form
the complete viral shell entity.
14.2
Sizes, Shapes, and Complexity of Nano-objects are Determined by the Nature and
Variety of the Constituent Building Blocks
In inorganic polyoxometalate systems, especially in solutions of molybdates under
reducing conditions, a ‘virtual library’ of well-defined linkable building blocks
exists, which can be connected under suitable conditions to form a plethora of sophisticated nanostructures. For instance, two or three identical well-defined building
blocks or fragments, each comprising 17 molybdenum atoms, become linked to
form the two different nanostructures shown in Figure 14.1 [3a,b]. All such cluster
species, emerging via self-assembly and woven from well-defined building blocks
Fig. 14.1. Two relatively large clusters with different structures
formed by the same {Mo 17 } building block: Two or three of
these {Mo 17 } building blocks are linked in different modes by
different linkers to form different clusters.
14.2 Sizes, Shapes, and Complexity of Nano-objects are Determined by the Nature 453
for chemists/scientists to build up systems with comparable functions that would
allow us to speak of machinery en miniature in Nature and technology. Remarkably,
from aqueous solutions of molybdates under reducing conditions, a huge variety of
interesting structures can be obtained which offer a unique substance library and
show really remarkable functionalities, even the phenomenon of cation transport
through pores and of modelling cell response. These nanoscaled systems emerge
by linking well-defined preformed building blocks under the canopy of self-assembly
processes, which are unique regarding the overwhelming variety obtainable. A textbook example is the generation of the tobacco mosaic virus (TMV) in two phases
[2]. In the first phase, the large protein building blocks are generated using encrypted genetic information and these in the second phase become linked to form
the complete viral shell entity.
14.2
Sizes, Shapes, and Complexity of Nano-objects are Determined by the Nature and
Variety of the Constituent Building Blocks
In inorganic polyoxometalate systems, especially in solutions of molybdates under
reducing conditions, a ‘virtual library’ of well-defined linkable building blocks
exists, which can be connected under suitable conditions to form a plethora of sophisticated nanostructures. For instance, two or three identical well-defined building
blocks or fragments, each comprising 17 molybdenum atoms, become linked to
form the two different nanostructures shown in Figure 14.1 [3a,b]. All such cluster
species, emerging via self-assembly and woven from well-defined building blocks
Fig. 14.1. Two relatively large clusters with different structures
formed by the same {Mo 17 } building block: Two or three of
these {Mo 17 } building blocks are linked in different modes by
different linkers to form different clusters.
14.2 Sizes, Shapes, and Complexity of Nano-objects are Determined by the Nature 453