Solution NMR spectra were recorded on a Bruker AVIII HD 400 spectrometer operating at 400.07 ( for the 4 and 3.2 mm rotors, respectively. Spectral simulations were performed in the solid lineshape analysis (SOLA) module v2.2.4 in Bruker TopSpin v3.6.3 and using EXPRESS 2.0 and WSolids1 ver 1.21.7. 96 1 H, C, and Si NMR spectra were referenced to SiMe4, and 31 P NMR spectra were referenced to 85% H3PO4.