Multidentate ligands for the synthesis of multi-metallic complexes

The reaction of the Schiff base species tris-((2-hydroxybenzylidene)aminoethyl)-amine (TrenSal) and tris-((2-hydroxy-5-bromobenzylidene)aminoethyl)amine (Tren5BrSal) with the acetates of nickel and zinc are reported. Two trimetallic complexes (M3L2) of Tren5BrSal with nickel and zinc have been crystallographically characterised. The attempted crystallisation of bis-(tris-((2-hydroxybenzylidene)aminoethyl)amine nickel) nickel from solutions containing TMEDA lead to the production of two novel complexes: namely a nickel adduct of the partially hydrolysed TrenSal ligand and an interesting nickel bromide–carbonate salt. [(TrenSal)2Ni3] is reacted with PbCl2 to form a novel tetrametallic complex, [{(TrenSal)Ni}Pb(NC5H5)Cl]2, where a Pb2Cl2 moiety replaces the nickel at the core of the complex. Extending the study to include the related hexadentate ligand, 1,1,1-tris-((2-hydroxybenzylidene)-aminomethyl)propane (TEtSal), we were able to isolate and characterise both [(TEtSal)2Ni3] and [{(TEtSal)Ni}2Pb].

Graphical abstractA number of multi-metallic Schiff base complexes (M3L2, M = Ni, Zn; Ni2PbL2 and Ni2Pb2L2) have been synthesised and crystallographically characterised. The attempted crystallisation of Ni3L2 leads to the production of two novel complexes: namely a partially hydrolysed Schiff base complex and an interesting nickel bromide–carbonate salt.Figure optionsDownload full-size imageDownload as PowerPoint slide