Nanoclusters formed from gold and phosphine ligands were among the first gold nanoclusters to be isolated and characterized crystallographically. In contrast to X-type thiolate ligands, L-type phosphine ligands can be expected to strongly electronicially couple to the cluster core and thus to exert more influence over the electronic properties of the cluster. For instance, substitution of a single PPh 3 ligand by an N-heterocyclic carbene ligand has been shown to significantly enhance the galvanic efficiency of catalytic Au 11 clusters. Mingos reported the crystal structures and spectra of a series of derivatives of Au 9 (PPh 3 ) 3+ 8 featuring -Me or -OMe substituents in the para-positions of the PPh 3 ligands which showed that substitution induced marked changes in the electronic spectra of the clusters, but these changes were masked by gross structural rearrangement induced by the ligands in the solid state. The Au 9 (PPh 3 ) 3+ 8 and closely-related Au 8 (PPh 3 ) 2+ 7 nanoclusters have been extensively investigated using quantum chemical, structural, spectroscopic, and mass spectrometric 25,26 techniques. Crystal structures show that both clusters are oblate, though Au 9 (PPh 3 ) 3+ can take on two different interchanging structural isomers in crystal structures in the presence of different counterions. Both clusters are best described within the superatomic model as 6-electron superatoms, having filled 1S, 1P x (HOMO-1), and 1P y (HOMO) orbitals. Despite not featuring a full 8-electron superatomic shell, their oblate structures are consistent with a geometric stabilization of the 1P x and 1P y and destabilization of the 1P z orbitals such that they feature a large HOMO-LUMO gap. The destabilization of the 1P z orbital is so significant that the apparent LUMO is actually the 1D x 2 -y 2 superatomic orbital rather than 1P z as would be expected.