Polynuclear Nickel(II) Complexes: Preparation and Magnetic Properties of NiII4, NiII5, and NiII6 Species with Ligands containing O∩X∩O (X = S, Se or N) Donor Atoms
✍ Scribed by Tapan K. Paine; Eva Rentschler; Thomas Weyhermüller; Phalguni Chaudhuri
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 234 KB
- Volume
- 2003
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Abstract
A family of bisphenol‐containing ligands with XO~2~ donor atoms, where X = S, Se, or N, yields [Ni^II^]~4~ (1) and (2), [Ni^II^]~5~ (3), and [Ni^II^]~6~ (4) complexes. Complex 2, 3, and 4 have been structurally characterised by X‐ray diffraction. The compounds were characterised spectroscopically and by variable‐temperature (2−295 K), variable‐field (1, 4, and 7 T) magnetic susceptibility measurements. Analysis of the magnetic data shows predominant ferromagnetic interactions between the nickel centres (S~Ni~ = 1) indicating “high‐spin” ground states for 1, 2, and 3, whereas complex 4 shows antiferromagnetic interactions. A plot of J vs. Ni−O−Ni angles for all structurally characterised Ni~4~O~4~ cubane cores, including 2, irrespective of their symmetry, shows a large variation of J values within a small range of Ni−O−Ni angles. A simple two‐J model was found to be adequate to describe the magnetic properties of the hexanuclear complex, 4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)