Magnetic Interactions in Dimeric Zn(II):Cu(II) (thiodiacetate) (phenanthroline)

N. I. NEUMAN; E. BURNA; A. C. RIZZI; C. D. BRONDINO

Chascomús, Buenos Aires

Encuentro; Fourth Latin American Meeting on Biological Inorganic Chemistry (LABIC),; 2014

The study of spin pairs coupled by exchange interaction is a research field that constitutes a crossing point between biology and physical chemistry.1-3 Weak exchange interactions can be correlated with chemical paths joining paramagnetic metals,4 and particularly the magnetic dipolar interaction (which has a 1/r3 dependence) is useful to determine distances between paramagnetic centers, which can be native metallic sites or organic radicals, or covalently attached spin labels. Also, when two anisotropic metal centers are coupled by dipolar interaction (which is inherently anisotropic), the coupling´s analysis can provide with a certain accuracy relative orientations between the g-tensors of each site.5 Although the theoretical principles governing magnetic interactions are well known,6 it is necessary to perform detailed studies of how magnetic properties are affected by subtle structural characteristics, in both low-molecular weight coordination complexes and metalloproteins. In this work we study Cu(II)-doped dimeric compound [Zn(II)2(tda)2(phen)2] ?H2tda (tda = thiodiacetate, phen = 1,10-phenanthroline), isostructural to the pure Cu(II) compound7 (see Fig. 1) and analyze the magnetic properties in the diluted compound and their relation to the properties previously studied in pure Cu(II)(tda)phen.