For example, in the context of developing selective hydrogenation/dehydrogenation catalysts based on single-sites or supported bimetallic nanoparticles, Ga@SiO2, prepared via Surface organometallic chemistry (SOMC), has been shown to consist of site-isolated tetra-coordinated Gaspecies dispersed uniformly across the surface of the silica support according to X-ray absorption nearedge structure (XANES), extended X-ray absorption fine structure (EXAFS) fitting, and wavelet transform (WT-)EXAFS (Figure ). While the immediate coordination environment of the Ga centres is known to consist of three anionic siloxide groups, the nature of the additional fourth neutral donor ligand remains unknown, and can be an adjacent siloxane bridge or silanol group (Figure ). (a) Current model for the structure of Ga@SiO2 based on characterization by X-ray techniques; (b) Overview of this work -NMR-based approach for identification of Ga-surface species found in Ga@SiO2, encompassing the use of well-defined molecular analogs, probe molecule studies and DFT models.