Conley, Matthew P.Rossini, Aaron J.Comas-Vives, AleixValla, MaxenceCasano, GillesOuari, OlivierTordo, PaulLesage, AnneEmsley, LyndonCoperet, Christophe2015-01-082015-01-082015-01-08201410.1039/c4cp01973chttps://infoscience.epfl.ch/handle/20.500.14299/109933WOS:000341064800052Grafting reactive molecular complexes on dehydroxylated amorphous silica is a strategy to develop ``single-site'' heterogeneous catalysts. In general, only the reactivity of isolated silanols is invoked for silica dehydroxylated at 700 degrees C ([SiO2-700]), though ca. 10% of the surface silanols are in fact geminal Q(2)-silanols. Here we report the reaction of allyltributylstannane with (SiO2-700] and find that the geminal Q(2)-silanols react to form products that would formally arise from vicinal Q(3)-silanols that are not present on (SiO2-700], indicating that a surface rearrangement occurs. The reorganization of the silica surface is unique to silica dehydroxylated at 700 degrees C or above. The findings were identified using Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy (DNP SENS) combined with DFT calculations.text::journal::journal article::research article