Synthesis and crystal structure of erbium complex with valine [Er₂ (Val)₄(H₂O)₈] (ClO₄)₆·4H₂O

The title complex was synthesized in aqueous solution, and its crystal structure was determined by X-ray diffraction. The crystal is tri-clinic space group P1 with a=1.00935(9) nm, b=1.20190(2) nm, c=1.28432(8) nm, α=95.013(9)°, β=102.814(5)°, γ=113.368(9)°, V=1.3676(3) nm³, Z=1, D_c=1.962 g/cm³. The complex is a dimeric molecule with four bridging carboxyl groups from four valine molecules between two erbium ions. Each erbium ion is coordinated by four oxygen atoms from four carboxyl groups and four oxygen atoms of four water molecules with the coordination number 8, taking a square anti-prism arrangement.