Layered [BaM(C₃H₂O₄)₂(H₂O)₄] (M = Fe or Co) Complexes − Spectroscopic, Magnetic and Thermal Study

Abstract

Complexes with formula [BaM(C 3 H 2 O 4 ) 2 (H 2 O) 4 ], where M = Fe or Co, were synthesised and characterised. These two types of complexes are isostructural and crystallise in the Pccn space group. Their structure consists of two-dimensional networks of octahedral MO 6 polyhedra in which the transition metal ions are coordinated by bridging malonate ligands, through the O-C-O atoms. These M-malonate units are extended along the crystallographic [101] plane. Spectroscopic data are consistent with the cations being in a high-

Long-range antiferromagnetic order in malonate-based compounds Na2M(H2C3O4)2·2H2O (M = Mn, Fe, Co, Ni)

“…12,13 Moreover, it has been shown that malonates can mediate significant ferromagnetic or antiferromagnetic interactions between TM. 5,8,9,[14][15][16][17][18][19] While the macroscopic magnetic properties exploration of TM molecular based compounds are routine, magnetic structure determination from neutron diffraction has been sporadic, because the distance between two transition metal ions can be fairly large and may prevent long-range ordering. Moreover, these ligands often present many hydrogen atoms which create diffuse scattering, making neutron diffraction experiments and their analysis more difficult; the use of deuterated ligands is indeed not always possible.…”

Oxalate-mediated long-range antiferromagnetism order in Fe2(C2O4)3·4H2O

“…[8][9][10][11][12] Their versatility is rich as they can coordinate 3d transition metals in various bridging modes: syn-syn, syn-anti, and anti-anti, through one or both carboxylate groups. 13,14 In particular, carboxylate can mediate significant ferromagnetic or antiferromagnetic interactions between TM, 8,11,12,[15][16][17][18][19][20] leading to properties such as magnetoelectricity and multiferroicity. 10,13,[21][22][23][24] Oxalate ions, thanks to their bis-chelating coordinating ability, have been largely employed to create two and three dimensional networks with the aim of creating new molecular-based magnets.…”