| Autor: |
Olson, Christopher, Heth, Christopher L., Lapidus, Saul H., Stephens, Peter W., Halder, Gregory J., Pokhodnya, Konstantin |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 7/14/2011, Vol. 135 Issue 2, p024503, 6p |
| Abstrakt: |
The M-[TCNE] (M = 3d metal; TCNE = tetracyanoethylene) system is one of the most interesting classes of molecule-based magnets, exhibiting a plethora of compositions and structures (inorganic polymer chains, 2D layers, 3D networks, and amorphous solids) with a wide range of magnetic ordering temperatures (up to 400 K). A systematic study of vibrational (both infrared and, for the first time, Raman) properties of the family of new TCNE-based magnets of MII(TCNE) (NCMe)2[SbF6] [M = Mn, Fe, Ni] composition is discussed in conjunction with their magnetic behavior and newly reso-lved crystal structures. The vibrational properties of the isolated TCNE•- anion in the paramagnetic Bu4N [TCNE•-] salt and recently characterized 2D layered magnet FeII(TCNE)(NCMe)2[FeCl4] are also reported for comparison. Additionally, a linear correlation between νC=C (ag) frequency of the TCNE ligand and its formal charge Z (the spin density on the π* orbital), Z = [1571 - νC=C (ag)]/154.5 [e], is presented. It is shown that monitoring Z by Raman spectroscopy is of great use in providing information that allows understanding the peculiarity of the superexchange interaction in M-[TCNE] magnets and establishing the structure-magnetic properties correlations in this class of magnetic material. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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