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MA: Fachverband Magnetismus
MA 16: Bio- and Molecular magnetism
MA 16.3: Talk
Tuesday, March 17, 2015, 10:00–10:15, EB 202
Electron spin density on the N atoms of CuII- bis(oxamidato) complexes: a pulse ELDOR detected NMR study — •Azar Aliabadi1, Ruslan Zaripov2, Mohammad A. Abdulmalic3, Evgeniya Vavilova2, Violeta Voronkova2, Tobias Rüffer3, Vladislav Kataev1, Kev Salikov2, and Bernd Büchner1 — 1IFW Dresden, Dresden, Germany — 2Zavoisky Physical Technical Institute, RAS, Kazan, Russia — 3Institute of Chemistry, TU Chemnitz, Chemnitz, Germany
Mononuclear Cu(II)- bis(oxamidato) complexes are used for the synthesis of their corresponding trinuclear complexes which are excellently suited to study magnetic superexchange phenomena.
To estimate the spin density distribution, which is a measure of the exchange constant, we have determined the hyperfine (HF) tensors for four N atoms of mononuclear Cu(II)- bis(oxamidato) complexes containing phenylene, ethyl and alkyl nitrogen ligands (CuN2arylN2ethyl/CuN2arylN2alkyl) by a pulse ELDOR detected NMR (EDNMR) experiment at 35 GHz and 20 K. We discuss a relationship between the spin density distribution of mononuclear complexes and the magnetic exchange couplings in their corresponding trinuclear complexes.
In particular, the obtained spin densities enable us to explain unexpectedly low J values of trinuclear Cu(II)-bis(oxamidato) complexes ( J = − [52− 66] cm−1) compared to the larger value for trinuclear Cu(II)-bis(oxamato) complex ( J = −89 cm−1).