Supramolecular zinc(II)salphen motifs: Reversible dimerization and templated dimeric structures

The formation of a dimeric structure of a nonsymmetric Zn(II)salphen complex is reported. The X-ray molecular structure show the formation of an oxygen-bridged species (2). In addition to this structure, a pyridine-ligated complex and an 1:2 dabco/Zn(II)salphen supramolecular assembly (dabco = diazabicyclo[2.2.2]octane) are presented. Their coordination behavior has been studied and can be correlated with the substitution pattern of the salphen ligand and the donor-strength of the involved axial ligands. The Zn(II)salphen building blocks bind in a cooperative fashion to the dabco template, the second unit being bound 4 times more strongly.

Graphical abstractThe formation of supramolecular dimeric zinc(II)salphen structures are reported, that are formed directly via an oxygen-bridged species or by using ditopic nitrogen ligands such as dabco (see figure). In the 1:2 dabco/Zn(II)salphen supramolecular assembly the Zn(II)salphen building blocks bind in a cooperative fashion to the dabco template, the second unit being bound 4 times more strongly.Figure optionsDownload full-size imageDownload as PowerPoint slide