Polymorphism in the spin-crossover ferric complexes [(TPA)Fe(III)(TCC)]PF6.
We have identified two polymorphs of the molecular complex [(TPA)Fe((III))(TCC)]PF(6) [TPA = tris(2-pyridylmethyl)amine and TCC = 3,4,5,6-tetrachlorocatecholate dianion]: one is monoclinic and the other is orthorhombic. By lowering the temperature both undergo a thermal spin-crossover between a high-spin (S = 5/2) and a low-spin (S = 1/2) state, which we detected by magnetic, optical and X-ray diffraction measurements. The thermal crossover is only slightly shifted between the polymorphs. Their crystalline structures consist of similar cation layers alternating with PF(6) anion layers, packed differently in the two polymorphs. The magnetic and optical properties of the polymorphs are presented.
Collet
Eric
E
Institut de Physique de Rennes, UMR-CNRS 6251, Université de Rennes 1 35042 Rennes Cedex, France. eric.collet@univ-rennes1.fr
Boillot
Marie Laure
ML
Hebert
Johan
J
Moisan
Nicolas
N
Servol
Marina
M
Lorenc
Maciej
M
Toupet
Loïc
L
Buron-Le Cointe
Marylise
M
Tissot
Antoine
A
Sainton
Joelle
J