Synthesis and Crystal Structure of Two Succinato‐Bridged Macrocyclic Nickel(II) Complexes

Two dinuclear succinato‐bridged nickel(II) complexes [Ni( RR ‐L)] 2 (μ‐SA)(ClO 4 ) 2 ( 1 ) and [Ni( SS ‐L)] 2 (μ‐SA)(ClO 4 ) 2 ( 2 ) (L = 5, 5, 7, 12, 12, 14‐hexamethyl‐1, 4, 8, 11‐tetraazacyclotetradecane, SA = succinic acid) were synthesized and characterized by EA, Circular dichroism (CD), as well as IR and UV/Vis spectroscopy. Single crystal X‐ray diffraction analyses revealed that the Ni II atoms display a distorted octahedral coordination arrangement, and the succinato ligand bridges two central Ni II atoms in a bis bidentate fashion to form dimers in 1 and 2 . The monomers of {[Ni( RR ‐L)] 2 (μ‐SA)} 2+ and {[Ni( SS ‐L)] 2 (μ‐SA)} 2+ are connected by O–H ··· O and N–H ··· O hydrogen bonds into a 1D right‐handed and left‐handed helical chain along the b axis, respectively. The homochiral natures of 1 and 2 are confirmed by the results of CD spectroscopy.