Synthesis and structural determination of a novel complex [Yb III (HEgta)] · 4H 2 O in comparison with [Yb III (HEgta)] · 2H 2 O

One novel ytterbium complex [Yb III (HEgta)] · 4H 2 O ( I ), where H 4 Egta = ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid, has successfully been synthesized by the reaction of Yb 2 O 3 with H 4 Egta in an aqueous solution after refluxing for 18 h. The crystal and molecular structures were determined by the infrared spectrum and X-ray crystallography. The crystal structural analysis reveals that central Yb(III) in I is eight-coordinated in a geometry of pseudo-square antiprismatic polyhedron by two amine N atoms, two ethylene glycol O atoms, and four carboxyl O atoms from one HEgta ligand and crystallizes in the orthorhombic crystal system with P 2 1 2 1 2 1 space group. The crystal data are as follows: a = 9.4927(8), b = 12.2627(13), c = 18.3657(17) Å, V =2137.9(4) Å 3 , Z = 4, ρ calcd = 1.934 mg/m 3 , μ = 4.448 mm −1 , F (000) = 1236, R = 0.0291, and wR = 0.0714 for 8850 observed reflections with I ≥ 2σ( I ). In addition, there is a protonated coordinated carboxyl O atom (O(5)) in the [Yb III (HEgta)] moiety.