Synthesis and characterization of lipophilic organotins. Application to the functionalization of silica gel
The synthesis of the lipophilic docosyltri(hex-1-ynyl)tin was achieved in three steps according to two different synthetic pathways. This compound reacted with nonporous silica to yield surface-modified silica via the loss of the three alkynyl functionalities and the formation of Sibulk_O-Sn-C bonds. The reactivity and the maximum chain loading reached were compared to those obtained with the heptadecafluorodecyltin analogue. The differences observed were rationalized in terms of electronic demand and cross-sectional area of the grafted chain, as evidenced by FTIR spectroscopy and X-ray crystal structures of the precursors.