Further studies on formamidinate dirhenium(III) complexes of the type Re-2(mu-form)(2)Cl-4 and the isolation and characterization of the ferrocenyl ligand Fe[eta(5)-C5H4C(NHCy)(NCy)](2)

dThe quadruply bonded dirheniuma(III) complexes trans-Rg(dpf)(2)Cl4H2O . 2T HF (1) (dpf= N,N ' -diphenylformamidinate) and Re-2(mu -RNCRO)(4)Cl-2 (R = Ph (2) or Cy (3)) have been prepared in good yield from the reactions of (n -Bu4N)(2)Re2Cl8 and Re-2(mu -O2CCH3)(4)Cl-2 respectively, with the appropri ate molten ligands dpfH and RNHCHO. The ferrocenyl ligand Fe[C5H4C(NHCy)(NC y)](2) (4) has been prepared but failed to yield dirhenium complexes that c ould be characterized. The structures of 1, 2 and 4 have been established b y single crystal X-ray crystallography. (C) 2001 Elsevier Science B.V. All rights reserved.