The novel dinuclear complex tetraaquahexakis(nitrato-O,O')bis(2,4,6,8-tetramethyl-2,4,6,8-tetraazabicyclo[3.3.0]octane-3,7-dione-O,O')dipraseodymium(III): Synthesis and crystal structure

Abstract

A centrosymmetric dinuclear complex, [Pr(C₈H₁₄N₄O₂)(H₂O)₂(NO₃)₃]₂ (I), was obtained from praseodymium(III) nitrate and the bicyclic bisurea 2,4,6,8-tetramethyl-2,4,6,8-tetraazabicy-clo[ 3.3.0]octane-3,7-dione (mebicar, Mc) and structurally characterized (CIF file CCDC no. 1435137). The crystals of complex I are triclinic: space group \(P\bar 1\), a = 9.8967(5), b = 10.3689(5), c = 11.0018(6) Å, α = 74.650(5)°, β = 68.064(5)°, γ = 67.257(5)°, V = 956.22(10) ų, ρ_calcd = 1.949 g/cm³, Z = 1. The praseodymium atom is coordinated to two O atoms of two Mc molecules (related by a center of symmetry), three bidentate nitrate anions, and two water molecules. So its coordination polyhedron has ten vertices; the Pr…Pr distance is 9.8726(7) Å.