Preparation, Structural Analysis, and Reactivity Studies of Phosphenium Dications
作者:Madelyn Qin Yi Tay、Gordana Ilić、Ulrike Werner-Zwanziger、Yunpeng Lu、Rakesh Ganguly、Louis Ricard、Gilles Frison、Duncan Carmichael、Dragoslav Vidović
DOI:10.1021/acs.organomet.5b00763
日期:2016.2.22
This work expands on the recent synthesis and reactivity of the two-coordinate P(III)-containing dication [((Ph3P)(2)C)P((NPr2)-Pr-i)](2+) (3a(2+)). Two additional dications of general formula [((RPh2P)(2)C)P(NR2')](2+) (3b(2+), R = 1/2 (CH2)(3), R' = Pr-i; 3c(2+), R = Ph, R' = Cy) have been prepared. Solution and solid-state P-31 NMR isotropic shifts for this dication class were observed around 360 ppm. Except for [3a] [SbF6](2), the P-31 CP/MAS NMR spectra reveal a high degree of structural disorder around the dicationic site in the solid state. Surprisingly, the synthesis of dication 3a(2+) was only possible in the presence of AlCl4-, SbF6-, and substituted tetraarylborates, while the use of ClO4-, OTf-, BF4-, PF6-, and BPh4- resulted in complex product mixtures. Single-crystal X-ray analysis of dications 3a(2+) and 3c(2+) suggested a 4 pi allyllike structure for the central CPN fragment, and this has been supported through detailed theoretical investigations. Initial reactivity studies between dications 3a(2+)/3c(2+) and PMe3 show an equilibrium between the free dication and the target adduct. Furthermore, 3a(2+) has been shown to be capable of O-H bond activation using water and methanol and polymerizes THE when it is dissolved in this solvent.