The condensation reaction should ideally produce only a single volatile byproduct SnMe3X (X = Cl, Me, or Et), corresponding to the type of reactive functional groups in the particular L-AlX 3 precursor. The analysis of the volatiles removed from the reactions, however, revealed that additional SnMe4 was generated even in the case of precursors containing the Al-Et and Al-Cl functional groups, leading to SnMe 3 Et/SnMe 4 and SnMe 3 Cl/SnMe 4 mixtures, respectively. Conveniently, no evidence of mutual interaction or substituent exchange was observed and the two byproducts could be distinguished and their molar ratio determined by 1 H NMR integration, allowing for a combined gravimetry/NMR quantification technique. The resulting values of the gravimetric degree of condensation of the -SnMe3 groups (DCG(SnMe3)) were compared to their spectroscopic counterparts calculated from Si MAS NMR integration (DC N (SnMe 3 )) and elemental analysis obtained from ICP-OES(Sn)/gravimetry (DC E (SnMe 3 )) (Table ) to make sure the quantification procedure was accurate. The resulting correlation plot (Figure ) shows generally good agreement among all three sources of information.