For 1-TPPO, δiso of 121 ppm and a CQ of 27.7 MHz are obtained, with an η of 0.006 (Figure , Table ). Again, the fitted δiso is consistent with values expected for a 4-coordinate Ga III site. The high axial symmetry, which arises from the presence of a C3 symmetry axis, as observed in the crystal structure (SI S3), results in a low η (i.e. an axially-symmetric distribution of electrical charge perpendicular to VZZ, SI S6). Overall, comparison of measured and calculated NMR parameters offer near-perfect agreement for each of the 3 molecules, 1-py, 1-TPPO and 1-THF. δiso(71Ga) values reflect those expected for tetracoordinate Ga-species containing oxygen-based ligands. The narrow chemical shift range illustrates that δiso offers insights into coordination number of Ga sites, but provides limited information about the additional neutral ligands when comparing subtle differences amongst structurally-related sites (vide supra). In contrast, CQ (VZZ) varies markedly within the series (Figure , Table ). The calculated VZZ values obtained for 1-py, 1-TPPO, and 1-THF differ markedly and rank as follows 1-THF (1.37 a.u.) > 1-TPPO (1.03 a.u.) > 1-py (0.96 a.u.) (n.b. only one of the sites for 1-THF is considered here).