Transition metal complexes polypyrazolylborates

Complexes of molybdenum form the largest set of any of the transition metals. Many of these compounds display spectroscopic properties, isomerism and structural features that illustrate the coordination chemistry of polypyrazolylborate complexes. In addition, this system illustrates that trispyrazolylborate ligands are more bulky than their formal analogue C5H5. 

The bonding of polypyrazolylborates to metal is determined primarily by the number of pyrazolyl groups attached to boron. Dipyrazolylborates are necessarily bidentate, and they form with divalent transition metal ions complexes, 1, that are similar to -diketonates but that are always monomeric for steric reasons. The major difference between dipyrazolylborates and -diketonates is that the R2B(pz)2M ring is not planar but is puckered in the boat form as in Structure 2. This results in asym-... 

Of the 33 papers presented at the symposium 32 are included in this volume. They are of two general types. One type discusses inorganic compounds exhibiting a specific property, most frequently electrical or photochemical. The second type reviews recent developments in the synthetic chemistry of a class of inorganic compounds— most often transition metal or lanthanide complexes— which are of potential interest to persons looking for new systems with unusual properties. Classes of compounds covered by this second type include metal alkyls, metal alk-oxides, metal alkylamides, metal chelates, and metal clusters as well as metal complexes with polyboranes, polyphosphines, macrocyclic derivatives, di- and triketones, and polypyrazolylborates as ligands. 

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