Journal of the American Chemical Society, Vol.129, No.2, 406-416, 2007
Isomerization dynamics and control of the eta(2)/N equilibrium for pyridine complexes
A series of pyridine complexes are prepared of the general form TpW(NO)(PMe3)(pyr) where pyr is either pyridine or a substituted pyridine. Depending on substitution pattern, the pyridine can be either N- or eta(2)-coordinated, and the role of the pyridine substituents and metal oxidation state in determining this equilibrium is explored. For eta(2)-pyridine complexes, the substituent pattern and solubility characteristics also determine the ratio of coordination diastereomers. Rates of both intra- and interfacial linkage isomerizations are explored along with the pyridine rotational barrier. This study is supported by DFT calculations and X-ray data and includes characterization of both eta(2)-pyridine and eta(2)-pyridinium complexes.