π-Indenyl substituted zirconium compounds containing terminal bonded phosphanylphosphido ligands [Ind 2 Zr(Cl){(Me 3 Si)P–PR 2 - κ P 1 }]. Synthesis, X-ray analysis and NMR studies

Dichloro-bis(indenyl)zirconium(IV) reacts with lithium derivatives of diphosphanes R2P–P(SiMe3)Li (R=tBu, Et2N, iPr2N) to form complexes with terminal phosphanylphosphido ligands – [Ind2Zr(Cl)-{(PSiMe3)P-PR2-κP1}]. These compounds are extremely sensitive towards moisture and oxygen. The solid state structures of these complexes were established by single crystal X-ray diffraction. The nitrogen bearing groups R (Et2N or iPr2N) significantly lengthen the P–P distances in the related complexes and change the geometry around the phosphido phosphorus in such a way that it becomes less planar.