Selective formation of lanthanide(III) complexes with polyaminopolycarboxylate: Unprecedented tetranuclear neodymium(III) complex containing alkoxo and carboxylato bridges

Lanthanide(III) Di- and Tetra-Nuclear Complexes Supported by a Chelating Tripodal Tris(Amidate) Ligand

“…In contrast to what is observed in 1 ·C 6 H 14 and 2 ·C 6 H 14 , the average κ 2 -amidate Nd–O bond distance (2.45(1) Å) and the average μ-O-amidate Nd–O bond distance (2.485(6) Å) are equivalent and significantly shorter relative to the average μ-O:κ 2 -amidate Nd–O bond distance (2.53(1) Å). The Nd–O bond distances in 3 ·C 6 H 14 are comparable to other reported Nd–O bond interactions. ,, Interestingly, the average μ-O:κ 2 -amidate Nd–O bond length is slightly longer than that same bond in 2 ·C 6 H 14 (2.501(2) Å), and the average μ-O-amidate Nd–O bond length is much shorter than the average μ-O-amidate Ln–O bond distances in 1 ·C 6 H 14 and 2 ·C 6 H 14 . These bonding differences may be due to several factors including the different crystallization space group and/or the increased steric congestion about the smaller Nd­(III) ion, both of which may influence the crystal packing and structural metrics.…”

“…The average Nd–O bond distance within the terminally bound DMF ligands (2.54(2) Å) and the average Nd–O bond distance within the bridging DMF ligand (2.541(1) Å) are statistically identical and are slightly shorter relative to both 1 ·C 6 H 14 and 2 ·C 6 H 14 . Lastly, the average Nd–N bond length (2.56(1) Å) is equivalent to the average Ln–N bond distances observed in 1 ·C 6 H 14 and 2 ·C 6 H 14 and is comparable to other reported Nd–N bonding interactions. ,, …”

“…The solid-state molecular structure of complex 3 (Figure 4) exhibits identical geometry and connectivity as 47,52,53 Interestingly, the average μ-O:κ 2 -amidate Nd−O bond length is slightly longer than that same bond in 2•C 6 H 14 (2.501(2) Å), and the average μ-O-amidate Nd−O bond length is much shorter than the average μ-O-amidate Ln−O bond distances in 1•C 6 H 14 and 2•C 6 H 14 . These bonding differences may be due to several factors including the different crystallization space group and/or the increased steric congestion about the smaller Nd(III) ion, 48 both of which may influence the crystal packing and structural metrics.…”

Magnetic Interactions in a Series of Homodinuclear Lanthanide Complexes

“…The χ M T value of the dinuclear Nd III 2 species at 300 K is 2.94 cm 3 K mol –1 ; for two independent Nd III ions with a 4 I 9/2 ground state a somewhat higher χ M T value of 3.28 cm 3 K mol –1 is expected at ambient temperature. In a known alkoxy-bridged dinuclear Nd III complex, a similar value for χ M T = 2.84 cm 3 K mol –1 was observed at 300 K . The χ M T value decreases steadily with decreasing temperature to a value of 0.94 cm 3 K mol –1 at 2.3 K, in agreement with antiferromagnetic intramolecular coupling.…”

Scandium, yttrium, the lanthanides and the actinides

“…3 , calcium is bound to a hexadentate EDTAM, with one bidentate nitrate, whilst in [La(EDTAM)(H 2 O) 4 ](NO 3 ) 3 Á H 2 O, nitrate is not bound, but beside hexadentate EDTAM, four waters are bound to La 46. Among polyaminopolycarboxylate complexes, an unusual example is the formation of a tetranuclear Nd complex, also the difference in stoichiometry associated with the Nd 2 {Nd(H 2 O) 2 } 2 (m 2 -dptaO) 2 (m 3 -dptaO) 2 ] 47. Several polyoxo-tungstates and -molybdates have attracted interest.…”