Structure of the Month – December 2010

Presented by:  Dr. Adrian B. Chaplin
Research Leader:  Prof. Andrew S. Weller
Published:  Journal of the American Chemical Society

Making and breaking C–C bonds in the solid state:  The structure of [Ir(BINOR‑S)(PiPr₃)][BAr^F₄] over the temperature range 100–250 K reveals a dynamic equilibrium between Ir(III) C–C agostic and Ir(V) bis-alkyl tautomers in the solid-state.  The solid-state dynamic behaviour is shown in the reaction scheme (a), with populations determined using X-ray diffraction (b) and the Van’t Hoff plot for this process (c, R2(fit) = 0.999).The disordered model at 150 K containing (d) Ir(III) and (e) Ir(V). The combined model and thermal ellipsoid plot of the structure refined without cation disorder modelling are also shown (f & g respectively).

Structure of the Month – December 2010