Bis-phosphorus stabilised carbene complexes
Abstract
The stabilisation of the carbene centre in a complex can be achieved either by the metal moiety or the carbon substituents. The balance between these two stabilising effects determines the nature of the MC bond and therefore the reactivity of the metal complexes. Introducing two vicinal phosphorus groups as substituents of the carbene centre proved to be rewarding, since depending on the coordination number of this atom different electronic properties are observed. Indeed, a σ3-P atom possesses a lone pair that can interact with a carbene centre by destabilising its vacant pπ orbital. On the contrary a σ4-P group presents low lying σ* orbitals which can be involved in delocalising electronic density in the