Bis-qtpy (qtpy=2,2’:6’,2”:6”,2”’-quaterpyridine) metal complexes, [M(qtpy)2]2+

Reactions of perchlorates of iron(II), nickel(II), and zinc(II) with 2,2¢:6¢,2¢¢:6¢¢,2¢¢¢-quaterpyridine (qtpy) gave the first crystallographically established bis-qtpy metal complexes of formula [M(qtpy)2][ClO4]2 (M ) Fe, Ni, Zn). Coordination of two terdentate quaterpyridines to the same center produces a distorted octahedron of six nitrogen atoms around the metal, leaving two pendant pyridyl groups, one for each quaterpyridine. For the diamagnetic zinc system, an NMR investigation has been carried out in order to establish the conditions to obtain the intermediate mono-qtpy complex, of formula [Zn(qtpy)(H2O)2][ClO4]2, which has also been crystallographically established. The corresponding hexafluorophosphate derivatives [M(qtpy)2][PF6]2 (M ) Ni and Zn) were prepared in DMF at room temperature.