Helicates Derived from Macrocyclic Ligand Systems

5 Helicates Derived from Macrocyclic Ligand Systems 

X-Ray structures of the corresponding cobalt(II), nickel(II) and zinc(ll) derivatives of 61 confirm that each of these complexes adopts a related helical geometry in which the co-ordination sphere is filled by six nitrogen donors from two essentially planar (meridionally co-ordinated) pyridine-2,6-diyldiimine units belonging to the macrocycle. 

Ligands 62 and 63 have been demonstrated to yield related helical complexes of type Both complexes correspond to the figure of eight motif illus- 

7C-stacking of the linking phenylene rings to take place. These rings adopt a parallel arrangement with an ideal separation of approximately 3.5 A in each complex. 

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