Metal-directed assembly of chiral bis-Zn(ii) Schiff base structuresElectronic supplementary information (ESI) available: Further analytical details, copies of relevant electronic spectra and additional X-ray/MS details. CCDC 871926 and 871927. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2dt30642e

Tetra-Schiff bases derived from (chiral) bis-salphen ligand scaffolds furnish, upon metalation with appropriate metal reagents, their multinuclear structures with associated Zn(OAc) 2 or Zn(OH) 2 fragments. The tendency of retaining these salts was investigated using four different (chiral) bis-salphen scaffolds. The presence of the additional Zn ions was supported by NMR studies, mass determinations and X-ray crystallography showing in two cases the possible mode of coordination within these multinuclear structures. In one case, dimerization of the Zn 3 complex leads to a unique hexanuclear Zn 6 complex being a mixture of diastereoisomeric complexes as revealed by NMR spectroscopy. The metal-mediated assembly of multinuclear bis-metallosalphens has been studied and has shown that the reaction stoichiometry as well as side-product formation may play a decisive role. The X-ray structures of two multinuclear species show how metal salts can direct this assembly process.