The open-chain triphosphanes RMe_2SiCH_2P(PR′ _2)_2 (R = Me, Ph; R′ = SiMe_3, Cy, Ph)

摘要

The triphosphanes RMe_2SiCH_2P(PR′_2) _2 (R = Me, Ph; R′ = SiMe_3, Cy) are synthesised in good yield via metathesis of organodichlorophosphanes and LiPR′ _2, while for R′ = Ph a propensity to form (Ph _2P)_2 precludes isolation of the in situ characterised triphosphanes. Where R = Me and R′ = SiMe_3 the triphosphane has also been characterised by single crystal X-ray diffraction and exhibits a single geometric conformer in the solid state, though solution-phase NMR spectra are indicative of facile conformational exchange across a wide temperature range. All of the described triphosphanes exhibit comparable behaviour, with their respective ~(31)P{~1H} NMR spectra manifesting anomalous 'second-order' characteristics, which are considered using full spin-Hamiltonian simulation. Preliminary studies of coordination chemistry and ancillary reactivity of the triphosphanes are described. This journal is