Spin Polarization and Ferromagnetism in Two-Dimensional Sheetlike Cobalt(II) Polymers: [Co(L)2(NCS)2] (L=Pyrimidine or Pyrazine)
✍ Scribed by Francesc Lloret; Giovanni De Munno; Miguel Julve; Juan Cano; Rafael Ruiz; Andrea Caneschi
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 128 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0044-8249
No coin nor oath required. For personal study only.
✦ Synopsis
The spin-polarization mechanism [1] describes how an unpaired electron on one atom polarizes the electron cloud on the adjacent atom in the opposite sense. This would result in an alternation of the spin density at atoms in a bridging unit, and consequently the sign of the magnetic exchange parameter J should alternate at each atom in the bridging unit. In this way, oligocarbenes or radicals linked through m-phenyl-common edges. Hence, there is no simple relationship between the structures of the title compound and NaNbS 2 .
The results presented clearly demonstrate the enormous synthetic potential of the reactive flux method. The mild reaction temperatures, at which the polychalcogenide building blocks are retained, together with a large pool of preparative data should enable the inorganic chemist to synthesize new compounds more predictably. This seems to be possible at least for the niobium compounds. In agreement with these assumptions we isolated the first chainlike niobium polyselenide using similar reaction conditions as for the sulfur compounds. [16] Again, its structure is based on [Nb 2 Q 11 ] 4À units connected through Se 2À 2 and Se 2À 3 ligands. It can be expected that many more new and interesting niobium compounds will be accessible by a systematic variation of the reaction conditions.