The crystal structures of the bis(terpyridyl)-metal(II) complexes [Co(L1)2][PF6]2 • 2.5MeCN, [Co (L2)2][PF6]2 • 3dmf, [Cu(L2)2] [PF6J2 • MeCN, [Zn(L1)2][PF6]2 • 2.5MeCN, and [Zn(L2)2][NO3]2 • 3dmf are reported, where L1 is 4′-(3,4-dihydroxyphenyl)-2,2′ : 6′,2″-terpyridine and L2 is 4′-(3,4-dimethoxyphenyl)-2,2′ : 6′,2″-terpyridine. The two CoII complexes and the CuII complex all show elongation along one axis in addition to the normal tetragonal compression imposed by terpyridyl chelates ; this is ascribed to the Jahn - Teller effect, in the case of the CoII complexes arising from the presence of a significant proportion of the low-spin state being present at the temperature used for the structural determination (173 K). The ZnII complexes are the first structurally characterised bis(terpyridyl)-ZnII compounds. These do not show the elongation along one axis that was apparent in the CoII and CuII structures. The relatively small bite angles for the terpyridyl chelates (ca. 150°, compared to ca. 160° for the first three complexes), results in a greater distortion away from regular octahedral geometry, reflecting the absence of stereoelectronic requirements for ZnII compared to CoII and CoII.
- Crystal structures