tris(bipyridine)ruthenium(III) as photosensitizer, ethylenediaminetetraacetic acid disodium salt as
sacrificial reagent, methyl viologen as electron relay, and a colloidal dispersion of polymer-protected
noble-metalclusters, prepared by alcohol-reduction, as catalyst. Among the noble-metalclusters
examined, Pt clusters showed the highest activity for the formation of methane as well as hydrogen.
In order to improve the activity, oxidized clusters and bimetallic clusters were also applied. For
example, the CH4 yield in 3-h irradiation increased from 51
equations having a deterministic sequence for a potential (A. Sütő
and H. Kunz). Finally a course on multifractal analysis is given by J. Peyrière.
The book reflects the intense scientific communication between mathematicians,
physicists and material scientists. It is a highly recommended compendium.
F. Kremer, Leipzig
U. Kreibig, M. Vollmer: Optical Properties of MetalClusters. Springer Series in Ma-
terial Science. U. Gonser, R. M. Osgood. Jr.. M. B. Panish, H. Sakaki (Eds.), Vol. 25.
Guest-Editor: J. P. Toennies, Springer, Berlin 1995. ISBN 3-540-57836-6, 532 pages
Pure & Appl. Chem., Vol. 63, No. 6, pp. 807-812, 1991.
Printed in Great Britain.
@ 1991 IUPAC
Theoretical aspects of metalcluster chemistry
D. Michael P. Mingos
Inorganic Chemistry Laboratory, University of Oxford, South Parks Road,
Oxford OX1 3QR
Abstract - During the last twenty years the Polyhedral Skeletal Electron Pair
Theory and the isolobal analogy have provided a theoretical basis for the
rapid experimental developments, which have occurred in metalcluster chemistry.
These theoretical principles have been underpinned
Terpenoid synthases are ubiquitous enzymes that catalyze the formation of structurally and stereochemically diverse isoprenoid natural products. Many isoprenoid coupling enzymes and terpenoid cyclases from bacteria, fungi, protists, plants, and animals share the class I terpenoid synthase fold. Despite generally low amino acid sequence identity among these examples, class I terpenoid synthases contain conserved metal-binding motifs that coordinate to a trinuclear metal cluster. This cluster not only serves to bind and orient the flexible isoprenoid substrate in the precatalytic Michaelis complex, but it also triggers the departure of the diphosphate leaving group to generate a carbocation that initiates catalysis. Additional conserved hydrogen bond donors assist the metal cluster in this function. Crystal structure analysis reveals that the constellation of three metal ions required for terpenoid synthase catalysis is generally identical among all class I terpenoid synthases of known structure.