Iron(II) Complexes of P3‐Chain Ligands: Structural Diversity

• Published in: Chemistry : a European journal 2023-12, Vol.29 (69), p.e202302661-n/a
• Main Authors: Holczbauer, Tamás, Gál, Dalma, Rohonczy, János, Matern, Eberhard, Sattler, Ewald, Bombicz, Petra, Kelemen, Zsolt, Kovács, Ilona
• Format: Article
• Language: English
• Subjects: Atomic properties; Chemical synthesis; Chemistry; Iron; Isomers; ligand effects; Ligands; Magnetic resonance spectroscopy; Metathesis; NMR spectroscopy; P ligand; Phosphorus; transition metal complex; X-ray diffraction
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202302661

Iron(II) complexes containing ligands with a R2P−P−PR2 unit were synthesized by metathesis reactions. With R=tBu, a mixture of two isomers is formed; in one of them, the terminal phosphorus binds to the Fe center (ylidic structure), while in the other one, the central P atom is linked to Fe. Starting from differently functionalized parent triphosphanes and corresponding functionalized Fe complexes, the ratio of isomers does not change. The outcome of the reaction and therefore the binding modes of the triphosphane ligands in the resulting compounds can be influenced by the size of the substituents. In the case of R=iPr a chelate complex is formed (both terminal P atoms are linked to the Fe center). Applying the mixed‐substituted triphosphane, the ylidic structure of the resulting complex is preferred. The new compounds were characterized by NMR spectroscopy in solution and single‐crystal X‐ray diffraction in solid‐state. The synthetic work was supported by DFT calculations. Iron(II) complexes containing a R2P−P−PR2 unit were synthetized. The binding modes of the triphosphane ligands can be changed by the size of the substituents. The products were characterized by NMR spectroscopy and single‐crystal X‐ray diffraction.