1 Stabilisation of an inorganic digallane by the phosphinobisthiolato P,S,S pincer ligand PPh(2-SC 6 H 4 ) 2 A. M. Vălean, a,b S. Gómez-Ruiz, b P. Lönnecke, b I. Silaghi-Dumitrescu, a L. Silaghi-Dumitrescu a,* and E. Hey-Hawkins b,* a Faculty of Chemistry and Chemical Engineering, “Babes-Bolyai” University, M. Kogălniceanu 1, 400082, Cluj-Napoca, Romania. b Institute of Inorganic Chemistry, Universität Leipzig, Johannisallee 29, 04103, Leipzig, Germany. UV-Vis spectroscopy – comparison between experimental and theoretical data Photochemical experiments were undertaken and followed by 1 H and 31 P{ 1 H} NMR spectroscopy to understand the decomposition mechanism of 4. The absorption spectra of both the ligand and complex recorded in CH 2 Cl 2 are shown in Figure S1. There are two absorption bands at 260 and 328 nm in the spectra of the complex 4 and two, at 255 and 280 nm, in the spectra of the ligand. By comparison of the two compounds, the absorbance of the complex at 260 nm can be assigned of π→π* transitions due to the ligand, while the other absorbance is the results of ligand→gallium transitions. Thus, in order to decompose the complex further UV irradiation of 4 was performed with a UV lamp at 366 nm. For the calculation of the molar absorptivity ε, Lambert-Beer’s law was used. Table S1. UV data of PS 2 H 2 and complex 4 Compound λ (nm) A ε (l·mol -1 ·cm -1 ) 255 2.65 91.912⋅10 3 PS 2 H 2 280 4.60 52.949⋅10 3 260 2.46 117.943⋅10 2 4 328 0.49 23.494⋅10 2 Supplementary Material (ESI) for New Journal of Chemistry This journal is (c) The Royal Society of Chemistry and The Centre National de la Recherche Scientifique, 2009