Crystal structure and spectral properties of the heterometallic 3d-4f complex of gadolinium (III) – cobalt (II) with ethylenediamine-N,N,N′,N′-tetraacetic acid

LUMINESCENT PROPERTIES OF Nd(III) COMPLEXES WITH ETHY­LENE­DIAMINE-N,N'-DISUCCINIC AND N,N-BIS(PHOSPHONO­METHYL)-2-AMINOPROPIONIC ACIDS

“…The cobalt ion is bound monodentately to the bridging β-carboxyl group and bidentately to the oxygen atoms of two α-carboxyl groups of the EDDS mo lecule [8]. The Nd(III) ion in the NdСoEDTA complex, similarly to Gd 2 Co 3 (EDTA) 3 (H 2 O) 11 [39], is in the coordination environment of NdO 10 (bent bicapped tetragonal antiprism) and is monodentately bound to six carboxylate oxygen atoms from three different EDTA molecules and to four oxygen atoms of water molecules. The Co(II) ion is in a distorted octahedral environment and is coordinated by two nitrogen atoms, four oxygen atoms of EDTA and one oxygen atom of a water molecule.…”

“…Obviously, this is related to the structure of the complexes. Com-plexes based on EDTA are characterized by the formation of net 2D polymers [39], which obviously causes the shielding of the emitting centers of the Nd 3+ ion, and is the reason for the low intensity and efficiency of luminescence.…”