Apart from NMR, EA and FTIR measurements, compounds 1 and 2 were investigated by means of EI-MS (figure , table ). Besides confirming the formation of the targeted compounds, this method provides possible decomposition pathways under harsh EI-MS conditions, although the fragmentation cannot be directly compared to the decomposition that occurs during a chemical vapor deposition process. Especially for alanes, the tendency of dimer formation for intermolecular stabilization can be traced, which has been observed before for complex 1. For the dihydride 1 the expected dimer [M2] + signal at m/z 299.22 can be seen with a relative abundance (rel. abund.) of 3.52 %, whereas the monomer peak [M] + at m/z 114.11 gives the strongest signal with 100 %. For 2, no dimer formation can