| Autor: |
Pantelis, Konstantinos N., Skiadas, Sotiris G., Lada, Zoi G., Clérac, Rodolphe, Sanakis, Yiannis, Dechambenoit, Pierre, Perlepes, Spyros P. |
| Předmět: |
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| Zdroj: |
New Journal of Chemistry; 7/7/2024, Vol. 48 Issue 25, p11221-11232, 12p |
| Abstrakt: |
The use of N-(2-carboxyphenyl)salicylideneimine (saphHCOOH) and N-(4-chloro-carboxyphenyl)salicylideneimine (4ClsaphHCOOH) for the synthesis of hexanuclear {Zn II4 M III2 } (M = Cr, Fe) complexes is described. [Zn4Fe2(saphCOO)6(NO3)2(EtOH)2] (1), [Zn4Cr2(saphCOO)6(NO3)2(H2O)2] (2) and [Zn4Fe2(4ClsaphCOO)6(NO3)2(EtOH)2] (3), as 4CH2Cl2·2EtOH (1, 3) and 4MeCN·2EtOH (2) solvates, have been isolated and their structures have been determined by single-crystal X-ray crystallography. The three complexes are centrosymmetric and almost isostructural. The metal topology can be described as two isosceles triangles which are linked through phenolate oxygen atoms of two 3.2111 (Harris notation) saphCOO2−/4ClsaphCOO2− ligands, each of which bridges exclusively three ZnII atoms. Four 2.1111 ligands are also incorporated in the molecules, each bridging one MIII center and one ZnII ion. The former is chelated with the Ophenolate, Nimine and one Ocarboxylate being the donor atoms (thus forming two 6-membered chelating rings with a common MIII–N edge), while the latter is bound to the other carboxylate oxygen. The coordination spheres are of the types {FeO4N2}/{ZnO4N}/{ZnO5} for 1 and 3, and {CrO4N2}/{ZnO4N}/{ZnO4} for 2. Complexes 1–3 are the first heterometallic complexes (with any metals) based on saphHCOOH and 4ClsaphHCOOH, thus illustrating their ability for the preparation of mixed-metal molecular species. Interesting H-bonding patterns are present in the crystal structures. The IR and Raman spectra of the solid complexes are discussed in terms of the coordination modes of the ligands involved, while molar conductivity data and UV/VIS spectra in CH2Cl2 are also reported and interpreted. The δ and ΔEQ57Fe-Mössbauer parameters of 1 and 3 at 300 and 80 K indicate isolated high-spin FeIII centers. Variable-temperature (1.8–300 K) magnetic susceptibility data for 1–3 suggest a very weak exchange interaction between the MIII ions in agreement with their long distances (∼9 Å) in the molecules. [ABSTRACT FROM AUTHOR] |
| Databáze: |
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