Two coordinated geometries of Mn2+ ions in one single molecule: Organic–inorganic hybrids constructed with tris(2-aminoethyl)amine and manganese halide and fluorescent properties

Abstract

The reaction of manganese(II) halide MnCl2·4H2O and tris(2-aminoethyl)amine N(CH2CH2NH2)3 in the concentrated acid HCl at 65°C resulted in the formation of an inorganic–organic hybrid complex: [(C6H22N4)2(H3O)(MnCl6)(MnCl5)(Cl)2]·3H2O (1) and a known byproduct [(C6H22N4)Cl4]·H2O. The analogue reactions between MnBr2·4H2O and N(CH2CH2NH2)3 in HBr acid gave a pure complex [(C6H22N4)2Br5](MnBr5) (2). Crystal structures revealed that Mn centers in 1 adopted trigonal bipyramidal and octahedral two geometries, while in 2 showed only trigonal bipyramidal geometry. Luminescent investigation exhibited complex 1 gave pink luminescence and complex 2 emitted yellow light in solid states, which were both directly originated from the coordinated geometries of Mn2+ ion.