Coordination of tridentate Schiff base derivatives of 4-aminoantipyrine to rhenium (V)

The potentially tridentate Schiff base derivatives H2nap and Hoap were synthesized by the condensation reaction of 4-amino-2,3-dimethyl-1-phenyl-5-pyrazoline (4-aminoantipyrine)with 2-aminobenzaldehyde and salicylaldehyde, respectively. The reaction of H2nap with [ReOBr3(PPh3)2] and cis-[ReO2I(PPh3)2](1) gives rise to the products [Re(nap)Br2(PPh3)]Br (2) and [ReO(OEt)(Hnap)(PPh3)]I (3), respectively. In 2 the ligand nap is coordinated as a tridentate imido-imino-ketone, while in 3 Hnap is bonded as an amido-imino-ketone. The reaction of Hoap with [ReO2I(PPh3)2] affords the product [ReO(OMe)(oap)(PPh3)]I (4). Spectroscopic data and the X-ray crystal structures of compounds 2-4 are reported.