Zinc and thiocyanate-mediated oxazolidine ring formation in a trinuclear zinc(II) complex: Synthesis, structure, and properties

A novel trinuclear zinc(II) complex, [Zn3L2(NCS)2], where L is the deprotonated form of 2-(3-(2-(2-hydroxy-3-methoxybenzylideneamino)ethyl)oxazolidin-2-yl)-6-methoxyphenol (H2L), has been unexpectedly prepared from the reaction of Schiff base ligand 2-((2-(2-hydroxyethylamino)ethylimino)methyl)-6-methoxyphenol (HL′) with 3-methoxysalicylaldehyde, ammonium thiocyanate, and zinc nitrate in methanol. The complex has been characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction studies. It is interesting that the Schiff base ligand HL′ used to prepare the complex was transferred to a novel ligand H2L, bearing newly formed oxazolidine ring. Zinc ion and thiocyanate anion may be the essential factors for the cyclorization. Thermal stability and fluorescent property of the complex were also studied.