Syntheses, Characterizations, and Reactivities of 4,5-Diazafluorenide Complexes of Palladium(II) and Rhodium(I)

The reaction of 4,5-diazafluorene (LH) and NaH generates NaL, which reacts with Pd(PPh3)2Cl2 and [Rh(COD)Cl]2 to afford [Pd(PPh3)ClL]2 (1) and Rh(COD)L (2), respectively. Both 1 and 2 were fully characterized by NMR, elemental, and single-crystal X-ray diffraction analyses. Compound 2 can promote the hydrogenation of a variety of terminal olefins, without affecting the carbonyl groups in the substrates. Attempts to crystallize NaL results in the formation of a partially protonated species, Na2(LH)2L2, whose structure is confirmed by X-ray crystallography.