RT Journal Article
T1 Tris(ethylenediamine) Cobalt(II) and Manganese(II) Nitrates
A1 Cortijo Montes, Miguel
A1 Valentín-Pérez, Ángela
A1 Rouzières, Mathieu
A1 Clérac, Rodolphe
A1 Rosa, Patrick
A1 Hillard, Elizabeth A.
AB Octahedral tris(ethylenediamine) coordination complexes demonstrate helicoidal chirality, due to the arrangement of the ligands around the metal core. The enantiomers of the nitrate salts [Ni(en)3](NO3)2 and [Zn(en)3](NO3)2 spontaneously resolve to form a mixture of conglomerate crystals, which present a reversible phase transition from space group P6322 to enantiomorphic P6522 or P6122, with the latter depending on the handedness of the enantiomer. We report here the synthesis and characterization of [Mn(en)3](NO3)2 and [Co(en)3](NO3)2, which are isostructural to the Zn(II) and Ni(II) derivatives. The Mn(II) analogue undergoes the same phase transition centered at 150(2) K, as determined by single-crystal X-ray diffraction, Raman spectroscopy, and differential scanning calorimetry. The Co(II) derivative does not demonstrate a phase transition down to 2 K, as evidenced by powder X-ray diffraction and heat capacity measurements. The phase transition does not impact the magnetic properties of the Ni(II) and Mn(II) analogues; these high spin compounds display Curie behavior that is consistent with S = 1 and 5/2, respectively, down to 20 K, while the temperature-dependent magnetic moment for the Co(II) compound reveals a significant orbital contribution.
PB MDPI
SN 2073-4352
YR 2020
FD 2020-06-03
LK https://hdl.handle.net/20.500.14352/8241
UL https://hdl.handle.net/20.500.14352/8241
LA eng
NO Unión Europea. Horizonte 2020
NO Centre national de la recherche scientifique (CNRS)
NO University of Bordeaux
DS Docta Complutense
RD 13 abr 2025