13 Chromium, molybdenum, and tungsten
Abstract
The following provides a selected highlight for each element of the chromium triad in 2003.
Chromium: A series of remarkably stable chromium(IV)
Molybdenum: Molybdenum(V) coordination complexes have been extensively studied to provide further insights into the active sites found within many molybdoenzymes. A nice example of a model complex that contains the heteroscorpionate
Tungsten: The field of molecular magnetism has exploited the use of the [W(CN)8]3− building block in preparing a range of 2-D and 3-D bimetallic assemblies. For example, [Cu(tn)]3[W(CN)8]2·3H2O and [Cu(pn)]3[W(CN)8]2·3H2O have a 2-D layer structure and the magnetic properties of the compounds show typical metamagnetic behaviour. The critical field at which the interlayer antiferromagnetic ground-state switches to a ferromagnetic state is approximately 1.25 T for [Cu(tn)]3[W(CN)8]2·3H2O and 0.35 T for [Cu(pn)]3[W(CN)8]2·3H2O at 1.8 K.