Bis-Hexaaquasodium Decaaqua-Monohydrogen-Hexasodium-Gadolinium-bis-(Nitrilo-Tris-Methylenephosphonate) Tetrahydrate: Synthesis, Structure, Chemical Bonding

Abstract

Bis-hexaaquasodium decaaqua-monohydrogen-hexasodium-gadolinium-bis-(nitrilo-tris-methylenephosphonate) tetrahydrate [Na(H₂O)₆]₂[GdNa₆H(H₂O)₁₀{N(CH₂PO₃}₂]·4H₂O (space group P2₁/c, Z = 2, a = 11.8168(7) Å, b = 10.5403(9) Å, c = 19.8094(10) Å, β = 94.232(5)) has been synthesized and isolated. The Gd³⁺ ion is coordinated in the configuration of an elongated rhombohedron in the environment of two acid residues {N(CH₂PO₃)₃}. Two rhombohedron’s vertices distant from its center are occupied by nitrogen atoms, and six nearest vertices are occupied by oxygen atoms. Six sodium ions form inorganic bridges P-O-Na-O-P. The structure of the obtained complex is confirmed spectroscopically. XPS data indicate the formation of coordination bonds Gd-N and multiple bonds Gd-O.