1.890 Å). For 1-TPPO, the O-Ga-O bond angles (θO-Ga-O) are found to be 111.4°, and the O-Ga-O(P) bond angle (θO-Ga-L) is found to be 107.5°. The 31 P solution chemical shift of 1-TPPO is shifted by around 14 ppm compared to TPPO (40.1 vs. 25.7 ppm), indicating that TPPO is bound to Ga in solution. Furthermore the 1 JC-P coupling of 111 Hz is consistent with reported coupling constants for related Al silsequioxane TPPO adducts (110.5 Hz) -larger than the reported 1 JC-P (104.6 Hz) for TPPO (SI S7). Analysis of the 31 P ss-NMR spectrum of 1-TPPO indicates that in the solid state there is a single species with an isotropic chemical shift of 42 ppm. Fitting of the CSA gives a span (Ω) of 92 ppm, and a skew (κ) of 1.00, which aligns well with fitting of the CSA for TPPO/GaLA. L axis. Qualitatively τ4' correlates with the strength of interaction of the L-type ligands with the empty 4pz orbital found on Ga (vide infra) -an observation which is supported by the ease of THF displacement by py or TPPO.