Stereochemistry for engineering spin crossover: structures and magnetic properties of a homochiral vs. racemic [Fe(N3O2)(CN)2] complex.

Qiang Wang (1, 2) , Shari Venneri (1) , Niloofar Zarrabi (1) , Hongfeng Wang (3) , Cédric Desplanches (3) , Jean-François Létard (3) , Takele Seda (4) , Melanie Pilkington (1)

1 Department of Chemistry
2 School of Chemistry and Chemical Engineering
3 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
4 Department of Physics and Astronomy [Bellingham]

The Schiff-base condensation of the R,R-(+)-diamine () with 2,6-diacetyl pyridine in the presence of FeII affords the macrocyclic complex [Fe(dpN3O2)(CN)2] () (dp = diphenyl) with ligand centred chirality comprising of a 1 : 1 mixture of LS 6- and HS 7-coordinate FeII centres. Variable temperature magnetic susceptibility and Mössbauer studies reveal that () undergoes an incomplete thermal SCO transition with a T1/2 = 250 K as well as a LIESST effect. In contrast its racemic counterpart () comprises of mostly LS FeII and exhibits no LIESST properties.

Domaines: Matériaux

Qiang Wang, Shari Venneri, Niloofar Zarrabi, Hongfeng Wang, Cédric Desplanches, et al.. Stereochemistry for engineering spin crossover: structures and magnetic properties of a homochiral vs. racemic [Fe(N3O2)(CN)2] complex.. Dalton Transactions, 2015, 44 (15), pp.6711-6714. ⟨10.1039/c5dt00357a⟩. ⟨hal-01139023⟩