Aza-metallacycles with a heptavalent Re (d 0 ) center.

The oxidation state of the metal center is important for a conjugated metallacycle. Although high valent d 0 -metallacycles of main groups and early transition metals have been reported, such examples of late transition metals are limited. The reactions of ReOCl 3 (PPh 3 ) 2 with 2-ethynyl anilines produced alkenyl amino Re(V) complexes, which can be further oxidized to Re(VII) aza-metallacycles. The conjugated rhenacycle is nonaromatic, however, with close to zero NICS values and localized currents observed by AICD and GIMIC studies.