Rhenium(V) complexes containing mono- and tridentate imido ligands : crystal structures, spectroscopic results and DFT optimization : research article

Rhenium(V) complexes containing the [ReX(PPh3)2]4+ (X = Br, I) moiety were studied. The reaction of N-(2-aminophenyl)salicylideneimine (H3pna) 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)I2(PPh3)2] with two equivalents of 2-aminophenol (H3ap) in ethanol led to the isolation of the '2+1' complex salt [Re(Hap)(H2ap)I(PPh3)2]I (2) in good yield. The Hap ligand is coordinated monodentately via the doubly deprotonated imido nitrogen, and H2ap 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.