705-36-2Relevant articles and documents
New Polynuclear Manganese(II) Complexes with Orotic Acid and some of its Derivatives: Crystal Structures, Spectroscopic and Magnetic Studies
Nepveu, Francoise,Gaultier, Nicolas,Korber, Nikolaus,Jaud, Joel,Castan, Paule
, p. 4005 - 4014 (2007/10/02)
Three polynuclear manganese(II) complexes containing orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H3L1) or one of its substituted derivatives 2L2) or 5-nitro-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid (H3L1)> have been synthesized and characterized by X-ray crystallography.UV/VIS and magnetic susceptibility measurements.Complex 1 consists of neutral 1)2(H2O)6> units, which form polymer chains along the z axis with a Mn(1)...Mn(2) distance in the unit cell of 5.628(1) Angstroem while the Mn(2)...Mn(2) distance in the chain is 4.715(1) Angstroem.Each unit cell of complex 2 contains one neutral centrosymmetric dimer 2)2(H2O)6> containing a short Mn...Mn distance and an antiferromagnetic exchange interaction is present.The experimental data were fitted to the susceptibility equations resulting from the Hamiltonian H = -2JS1S2 to give exchange parameter J = -1.3 cm-1 and g = 1.95.From EPR spectra of 2, the hyperfine interaction parameter A = -0.27 GHz and the zero-field splitting parameter D = +/-2.93 GHz have been calculated.Each unit cell of complex 3 consists of one dinuclear anion 3)2(H2O)4Cl2>2- and of one cation 2+.The Mn(1) and Mn(2) atoms and the water molecule of the cation 2+ are situated at inversion sites.The dinuclear anions are associated to form chains but the shortest Mn...Mn distance of 5.642(3) Angstroem is observed within the 3)2(H2O)4Cl2>2- unit between Mn(1) and Mn(2).