Synthesis of Ethylene‐bridged Heterocyclic Bidentate P(III)N‐Ligands — Oxidation and Complexation Studies

Abstract

A series of phosphor(III)inanone ligands 4-7, linked by ethylene bridges between the nitrogen atoms of the heterocyclic rings, were synthesized by the reaction of the bis-PCl derivative 3 with the appropriate trimethylsilylamines. The bis-phosphor(V)inanone compounds 8-11 were obtained by the oxidation of 4-7 with hexafluoroacetone (HFA). Oxidation of 4 and 6 with tetrachloroorthobenzoquinone (TOB) gave the bis-phosphor(V)inanones 12 and 13. The reaction of 4-6 with [Pt(COD)Cl 2 ] led to the platinum complexes 14-16. All the σ 3 -phosphorinanone compounds 4-7 and the σ 5 -phosphorinanone compounds 8-10, 12 and 13 exist as a mixture of two conformers, as indicated by two signals in the 31 P-NMR Synthese von ethylen-verbrückten heterocyclischen P(III)N-Liganden ؊ Untersuchungen der Oxidation und KomplexierungInhaltsübersicht. Eine Serie von Phosphor(III)-inanon-Liganden 4-7, durch Ethylengruppen zwischen den Stickstoffatomen der heterocyclischen Ringe verknüpft, wurden durch Umsetzung der Bis-PCl-Verbindung 3 mit den entsprechenden Trimethylsilylaminen synthetisiert. Die Bis-phosphor(V)-inanon-Verbindungen 8-11 wurden durch Oxidation von 4-7 mit Hexafluoraceton (HFA) erhalten. Die Oxidation von 4 und 6 mit Tetrachlor-o-benzochinon (TOB) führte zu den Bis-phosphor(V)-inanonen 12 und 13. Durch Umsetzung von 4-6 mit [Pt(COD)Cl 2 ] (COD ϭ 1,5-Cyclooctadien) wurden die Platinkomplexe 14-16 erhalten. Die σ 3 -Phosphorina-1953 spectra. However, compounds 9 and 11 exist as single conformers, both display only one sharp singlet in the 31 P-NMR spectra. The Pt-complexes 15 and 16 contain two conformers; one conformer of 16 could be isolated by crystallization. X-ray crystal structure determinations for compounds 8, 14 and 16 were conducted, revealing inversion symmetry for 8 and cis arrangement for 14 and 16.