POLY 271 |
| Ferrocene-containing compounds are nowadays ubiquitous and indispensable to the development of research areas such as homogeneous catalysis and materials science. In stark contrast, the modification of other sandwich complexes is significantly less developed. For instance, little use has been made of cycloheptatrienyl-cyclopentadienyl sandwich complexes of the type [(Cht)M(Cp)] (M = group 4, 5 or 6 metal). In this contribution, we would like to report the synthesis and reactivity of highly strained ansa-Cht-Cp complexes of type I, which have been shown to be susceptible to strain release by undergoing ring-opening polymerization reactions. In addition, the bending of the two rings in the 16-electron complexes I creates a gap at the titanium center, which thereby becomes accessible to monodentate ligands such as CO or isocyanides. In contrast, the formation of thermally labile isocyanide and phosphine adducts can be observed for the zirconium complex II without the prerequisite of introducing a bridging unit. Thus, its functionalization to give the phosphino-trozircocenes III results in valuable building blocks with a Lewis-basic phosphorous atom next to a Lewis-acidic metal atom, a situation which gives rise to a rich metallo-supramolecular chemistry by intermolecular interaction between these centres.
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Metal-Containing and Metallo-Supramolecular Polymers and Materials
1:00 PM-4:45 PM, Monday, August 20, 2007 Westin Boston Waterfront -- Stone, Oral
Division of Polymer Chemistry |
