Rhenium(V) Complexes Containing Mono- and Tridentate Imido Ligands: Crystal Structures, Spectroscopic Results and DFT Optimization

Rhenium(V) complexes containing the [ReX(PPh3)(2)](4+) (X = Br, I) moiety were studied. The reaction of N-(2-aminophenyl)salicylideneimine (H(3)pna) with trans-[ReOBr3(PPh3)(2)] produced the complex salt [Re(pna)Br(PPh3)(2)]0.5Br.0.5(ReO4) (1), in which the tridentate ligand pna is coordinated via a doubly deprotonated nitrogen (as an imide), an imino nitrogen and a deprotonated phenolate oxygen atom. The reaction of trans-[ReO(OEt)I-2(PPh3)(2)] with two equivalents of 2-aminophenol (H(3)ap) in ethanol led to the isolation of the '2 + 1' complex salt [Re(Hap)(H(2)ap)I(PPh3)(2)]I (2) in good yield. The Hap ligand is coordinated monodentately via the doubly deprotonated imido nitrogen, and H(2)ap is chelated bidentately through the neutral amino nitrogen and a deprotonated phenolate oxygen atom. The crystal structures of 1 and 2 were determined by X-ray single crystal diffraction. Spectroscopic results and DFT calculations are also reported.