“…In the case of N -allylurea, the presence of the vinyl group should in principle allow a simple attachment strategy on silicon surfaces, with formation of covalent Si–C bonds through a [2 + 2]-like cycloaddition or through hydrosilylation. , Both attachment strategies guarantee the availability of the amine and/or the carbonyl as terminal groups. On the (7 × 7) surface, a cycloaddition-like mechanism, where cleavage of the CC bond is followed by the formation of two Si–C bonds at neighboring rest atom–adatom sites, has been observed for instance for ethylene adsorption − and proposed also in the case of N,N -dimethylallylamine, cyclohexene, and N -methylpyrrole . On the other hand, the hydrosilylation mechanism typically takes place at hydrogenated surfaces. − Indeed, for hydrosilylation to take place on the Si(111)-(7 × 7) surface, a proper amount of hydrogen atoms, possibly derived from other concomitant reactions, is required.…”