Investigating the Conformations of a Family of [M2L3]4+ Helicates Using Single Crystal X-ray Diffraction

We present five new dinuclear triple helicate compounds of types [Mn2L3](ClO4)(4), [Co2L3](BF4)(4), [Ni2L3](BF4)(4), [Cu2L3](BF4)(4), and [Zn2L3](BF4)(4), where L is a previously reported semi-rigid ligand incorporating two alpha-diimine primary donor groups and two secondary 4-pyridyl donor groups. All complexes have been characterized in both solution and the solid state. Single crystal X-ray diffraction studies were used to probe the variation in the respective helical structures as the coordinated metal ion was altered, including the effect on the orientations of the secondary binding domains. The influence of the metal ion size, the spin state in the case of Fe(II), and the presence of Jahn-Teller distortions on the overall helical structure has been investigated. These results form a basis for the design and construction of new large metallosupramolecular architectures which manifest properties associated with the constituent helical metalloligand units.

Automated summary

In this study, five new dinuclear triple helicate compounds were presented, including [Mn2L3](ClO4)(4), [Co2L3](BF4)(4), [Ni2L3](BF4)(4), [Cu2L3](BF4)(4), and [Zn2L3](BF4)(4), which were characterized in both solution and the solid state. The influence of the coordinated metal ion on the helical structures and the orientations of the secondary binding domains was investigated. These findings provide a basis for the design and construction of new large metallosupramolecular architectures.