Biaryl-based macrocyclic and polymeric chiral (salophen)Ni(II) complexes: Synthesis and spectroscopic study

Polymeric/oligomeric and macrocyclic (salophen)Ni(II) complexes have been s ynthesized starting from both an achiral biphenol dialdehyde and an optical ly active BINOL dialdehyde. It was found that these polysalophens contain n onplanar coordination of Ni(II) units that are paramagnetic. This is differ ent from the previously reported (salophen)Ni(II) complexes which are squar e planar and diamagnetic. The nonplanar (salophen)Ni(II) units make the new polymeric Ni(II) complexes different from the helical structure proposed f or chiral biaryl-based polymers containing square-planar (salophen)Ni(II) u nits. The copolymerization of the chiral binaphthyl monomer with the achira l biphenyl monomer demonstrates that the chirality of the binaphthyl unit i s not propagated along the biphenyl polymer chain.