14
Oxomolybdates: From Structures to Functions
in a New Era of Nanochemistry
A. Mu ¨ller and S. Roy
Abstract
From a unique library containing the molybdenum-oxide based building blocks/
fragments under reducing conditions in aqueous solution a huge variety of nanoobjects, allowing specific reactions at well-defined positions, can be generated. This
enables us to perform a new type of nanochemistry. Examples include the wellknown molecular big-wheels of the type {Mo 154 } and {Mo 176 } and the spherical
clusters of the type {Mo 132 } and their derivatives. These are considered here
in connection with the by far the largest structurally well-characterized cluster
{Mo 368 }, which contains besides the 368 molybdenum atoms nearly 2000 nonhydrogen atoms, shows positive and negative curvatures, and has the size of
hemoglobin and the shape of a lemon. A most recent achievement regarding a
unique ‘nanosponge’-behaviour of the spherical clusters showing responsive sensing opens new eras of nanochemistry: nano-spherical-surface, nano-porous-cluster, and
nano-super-supramolecular chemistry. Historically speaking, after solving the mystery
of molybdenum blue solutions, from which the wheel type clusters can be isolated,
it became evident that the acquired knowledge could be useful for advancing the
frontiers of materials science. Some general aspects of the corresponding chemistry are reviewed here.
14.1
Introduction: Similarities between Nanotechnology in Nature and Chemistry?
Der chemische Prozeß ist das ‘Ho ¨chste, wozu die unorganische Natur gelangen kann’.
G. W. F. Hegel [1]
Nature plays with patterns. Patterning reaches a pinnacle of elegance and intricacy
in nanoscopic molecular systems, the most relevant being those found in the biosphere: the variety of specific processes of the living cell are directed by an overwhelming number of nanoscaled structures, for example by the proteins which can
act as carriers, fighters, administrators, food engineers, signal receivers and transductors
452
Oxomolybdates: From Structures to Functions
in a New Era of Nanochemistry
A. Mu ¨ller and S. Roy
Abstract
From a unique library containing the molybdenum-oxide based building blocks/
fragments under reducing conditions in aqueous solution a huge variety of nanoobjects, allowing specific reactions at well-defined positions, can be generated. This
enables us to perform a new type of nanochemistry. Examples include the wellknown molecular big-wheels of the type {Mo 154 } and {Mo 176 } and the spherical
clusters of the type {Mo 132 } and their derivatives. These are considered here
in connection with the by far the largest structurally well-characterized cluster
{Mo 368 }, which contains besides the 368 molybdenum atoms nearly 2000 nonhydrogen atoms, shows positive and negative curvatures, and has the size of
hemoglobin and the shape of a lemon. A most recent achievement regarding a
unique ‘nanosponge’-behaviour of the spherical clusters showing responsive sensing opens new eras of nanochemistry: nano-spherical-surface, nano-porous-cluster, and
nano-super-supramolecular chemistry. Historically speaking, after solving the mystery
of molybdenum blue solutions, from which the wheel type clusters can be isolated,
it became evident that the acquired knowledge could be useful for advancing the
frontiers of materials science. Some general aspects of the corresponding chemistry are reviewed here.
14.1
Introduction: Similarities between Nanotechnology in Nature and Chemistry?
Der chemische Prozeß ist das ‘Ho ¨chste, wozu die unorganische Natur gelangen kann’.
G. W. F. Hegel [1]
Nature plays with patterns. Patterning reaches a pinnacle of elegance and intricacy
in nanoscopic molecular systems, the most relevant being those found in the biosphere: the variety of specific processes of the living cell are directed by an overwhelming number of nanoscaled structures, for example by the proteins which can
act as carriers, fighters, administrators, food engineers, signal receivers and transductors
452