Multiple metal coordinating behaviour of the tetrapodal ligand 1,1,1,1-tetrakis[(salicylaldimino)methyl]methane

The tetrapodal ligand 1,1,1,1-tetrakis[(salicylaldimino)methyl]methane (H4tsam) has been introduced for the first time for metal complexation. Two zinc(II) complexes[Zn2(tsam)] (1) and [Zn3(Htsam)2]·2C7H8 (2) have been obtained by reacting zinc acetylacetonate with the ligand in the presence of triethylamine, while a cobalt(III) complex [Co(Htsam)]·CH3CN·H2O (3) is obtained when Co(ClO4)2·6H2O is reacted in air. All the compounds have been characterized by their elemental analyses and ESI-MS, IR, UV-VIS and 1H NMR spectra. The X-ray crystal structures of H4tsam, 2 and 3 have been determined. Compounds 1 and 2 exhibit fluorescence in solution and the lifetimes of their luminescence decay have been measured. Thermal analysis (TGA, DTA) of 2 with regard to loss of encapsulated toluenes and redox behaviour of 3 have been studied.

Graphical abstractThree different modes of metal binding are exhibited by the titled ligand (H4tsam) in the complexes [Zn2(tsam)], [Zn3(Htsam)2]·2C7H8 and [CoIII(Htsam)]·CH3CN·H2O.Figure optionsDownload full-size imageDownload as PowerPoint slide