Seven-coordinate [ReVON4X2]+ complexes (X = O and Cl)

The oxorhenium(V) complexes with ligands containing N-4 (H(2)pmen) and N4O2 (H(2)bbpen, H(2)Clbbpen, and H(2)bped) donor atom sets have been synthesized. X-ray crystallographic analyses of the [ReO(H(2)pmen)Cl-2](+), [ReO(bbpen)](+), and [ReO(bped)](+) complexes showed that all three cations share a rate seven-coordinate structure with a distorted pentagonal bipyramidal geometry, which represents a novel and potentially general structural motif in Re-V=O complexes. H-1 NMR spectroscopy shows that the structures of the complexes are retained in the solution.