[Cp2M] metallocene species promoted reductive coupling of Cl2C=PR: Synthesis, structure, and reactivity of the first 3,4-dihalo-1,2-dihydro-1,2-diphosphetes

N. Cenac (1) , Anna Chrostowska (2) , Jean-Marc Sotiropoulos (3) , Bruno Donnadieu (1) , Alain Igau (1) , G. Pfister-Guillouzo , Jean Pierre Majoral (1)

1 LCC - Laboratoire de chimie de coordination
2 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
3 IPREM - Institut pluridisciplinaire de recherche sur l'environnement et les matériaux

Early metallocene transition complexes [Cp2M] (M = Zr, Ti) react with C-dihalogenated phosphaalkenes R2NP=CCl2 [R2N = 2,2,6,6-tetramethyl-N-piperidyl (TMP), (Me3Si)2N] to give 3,4-dihalo-1,2-dihydro-1,2-diphosphetes (R2NPCCl)2. A single crystal X-ray determination of [(TMP)PCCl]2 reveals an unprecedented stretched phosphorus-phosphorus bond (2.320(4) Å) due to a negative hyperconjugation between the nitrogen lone pairs of the amino groups and the antibonding σ*PP orbital. Experimental results, ab initio 6-31G(d,p)//MP2 calculations, and photoelectron analysis are consistent with a strong interaction of the π-HOMO of R2NP=CCl2 and the 2a1 orbital of the metallocene [Cp2M] fragment as the first step in the formation of (R2NPCCl)2.

Domaines: Chimie inorganique; Chimie organique

N. Cenac, Anna Chrostowska, Jean-Marc Sotiropoulos, Bruno Donnadieu, Alain Igau, et al.. [Cp2M] metallocene species promoted reductive coupling of Cl2C=PR: Synthesis, structure, and reactivity of the first 3,4-dihalo-1,2-dihydro-1,2-diphosphetes. Organometallics, 1997, 16 (21), pp.4551--4556. ⟨10.1021/om970387n⟩. ⟨hal-01566365⟩