The direct metalation of phthalazinium halides with Rh(~tBuO)(COD)_2 or Ir(~tBuO)(COD)_2 led to the isolation of stable MCl(phthalazin-2-ylidene)X(COD) (M = Rh, Ir) as a new family of cyclic amino aryl carbene transition metal complexes. The X-ray diffraction analysis of several representatives systematically revealed a relatively short C(aryl)-C(carbene) bond distance of 1.44-1.46 ?, shorter than the typical C(sp~2)-C(sp~2) single bond, indicating some electron density delocalization from the π system of the aryl ring over the vacant carbene orbital.
展开▼
