| Summary: | This thesis investigates the synthesis, structure and characteristic reactivity of a series of
novel chromium nitrosyl complexes. Many compounds of the form Cr(NO)(N'Pr₂)R₂ can be
prepared by treatment of the bis(benzoate) precursor Cr(NO)(N'Pr₂)(0₂CPh) ₂ with the
appropriate MgR₂ reagent. The resulting formally unsaturated bis(hydrocarbyl) complexes
exhibit interesting features in their solid-state molecular structures. For example, when R = Bz
there exists both an agostic hydrogen interaction from the amide ligand as well as an ƞ²-benzyl
interaction. In solution, the bis(hydrocarbyl) complexes are fluxional, demonstrating rotation
about the chromium-amide bond. Variable temperature ¹H NMR spectroscopy has been
employed to study this phenomenon.
In one instance, with R = o-tolyl, a different reaction pathway is followed. Instead of the
bis(hydrocarbyl) complex, a nitrosyl-cleaved oxo imido compound Cr(0)(N'Pr₂)(NR)R is
isolated. The solid-state molecular structure of this compound exhibits a Cr-N(imido)-C bond
angle that is more bent than in any other previously prepared metal-imido complex.
The reactivity of the bis(hydrocarbyl) complexes has also been explored. The insertion
of isocyanides into one of the Cr-C bonds of these species proceeds smoothly, although
reactions with carbon monoxide and ethylene are not as straightforward. Experiments with
Lewis bases, Bronsted-Lowry acids, water and dioxygen are also complicated, most likely due to
the inherent instability of the complexes. In that regard, the thermolysis of the bis(hydrocarbyl)
compounds is investigated. β-Hydrogen elimination from the amide ligand is shown to be a
favourable reaction pathway, and this is believed to lead to the decomposition of the
bis(hydrocarbyl) compounds.
In many cases, computational means have also been utilized as a means of gaining insight
into the experimental observations. === Science, Faculty of === Chemistry, Department of === Graduate
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