Seven- And Eight-Coordinate Complexes of Indium(iii) With Nitrilotriacetate

Abstract

The crystal structures of three indium(lll) complexes with nitrilotriacetate (nta) have been determined. Crystallographic data for the compounds are as follows: [ln(nta)(H20)2] n .2nH20(1), orthorombic, space group P2 1 2 1 2 1 , a = 7.870(1), b = 11.505(2), c = 13.721(3) A, V = 1242.4(4) A 3 and Ζ = 4; Κ 3 [Ιη(ηί3) 2 ].5Η2θ (2), monoclinic, space groupP2i/c, a = 15.599(4), b = 9.814(2), c = 16.057(4) Α, β = 110.00(2)°, V = 2310(1) A 3 and Ζ = 4; {C(NH 2 )3}3[ln(nta) 2 ].2H 2 0 (3), triclinic, space group ΡΪ a = 9.517(3), b = 9.717(2), c = 15.306(4) Α, α = 76.17(2), β = 89.47(2), γ = 88.75(2)°, V = 1374.1(6) A 3 and Ζ = 2. In the polymeric-chain structure of 1 the In atom is seven-coordinated by two water molecules and nta 3 ", the latter being quadridentate towards one indium and forming bridges between two metal centres, whereas compounds 2 and 3 have monomeric structure with eight-coordinate complex anions containing two quadridentate nta ligands. The coordination geometry around the In atom is: a trigonal prism capped on a square face (1), a nearly ideal dodecahedron (2) and a highly distorted tetragonal antiprism (3).

Chelation in One Fell Swoop: Optimizing Ligands for Smaller Radiometal Ions

“…Seven-coordinate metal complexes are far fewer in the literature than 4–6 coordinate analogues. In particular for In 3+ only a handful of structures have been reported, and this work makes a significant addition. − Owing to their relatively similar size and preference for coordination numbers 6–8, both Sc 3+ (0.74 Å, CN-6) and In 3+ (0.80 Å, CN-6) metal ions form very similar hepta-coordinated complexes with hexadentate glyox 3– plus a water molecule …”

Comparison of Yttrium and Indium Complexes of DOTA-BA and DOTA-MBA: Models for 90Y- and 111In-Labeled DOTA−Biomolecule Conjugates

“…The coordination number of indium is typically 6 or 7 (51)(52)(53)(54)(55). Only a few eightcoordinate indium complexes are known (56)(57)(58).…”

Novel cadmium–organic frameworks with nitrilotriacetate

“…Cd(1) is coordinated to two water molecules, one BPY and to all possible coordination sites of the polydentate NTA 3À , with a coordination geometry best described as a capped octahedron, just as that observed for CUmof-7 in the Cd-NTA moieties (the seventh capping position is here also occupied by the N-donor atom from NTA 3À ). Cd(2) coordination geometry resembles a pentagonal bipyramid, with the equatorial plane being formed by three water molecules and a carboxylate group from NTA 3À [C (34)], connected in a slightly asymmetric 2 -syn, synchelate coordination fashion (Table 5). Two N-donor atoms from bridging-BPY ligands are trans-coordinated in the axial positions.…”

“…29 Just like HDTPA 4À , nitrilotriacetic acid (H 3 NTA) is also a precursor of a multidentate organic ligand (NTA 3À ), incorporating carboxylic acid groups and one N-donor atom, capable of coordinating to several metal centers and also of eliminating available coordination sites. Surprisingly, a search in the Cambridge Structural Database 32 produced only a few one-, [33][34][35][36][37][38] two- 38,39 and three-dimensional [40][41][42] MOFs with H x NTA residues. We felt that this molecule could be used as a building block in the construction of novel crystal structures with characteristics similar to CUmof-2.…”