Abstract Four rhodium 4, 5-diazafluorene derivatives,[RhL (PPh 3) 2](1),[Rh (H) 2 (LH)(PPh 3) 2] Cl (2),[Rh (H) 2 L (PPh 3) 2](3) and [Rh (H) 2 (LH)(PPh 3) 2] OTf (4), have been synthesized and fully characterized by NMR spectroscopy, elemental analysis and single- crystal X-ray diffraction. Compound 1 can be converted into 3 when treated with hydrogen gas. Compound 2 can be converted into 3 when treated with NaH, and the reverse ...