The bonding of aldehydes on aluminium: benzaldehyde on Al(111)

The adsorption of benzaldehyde on Al(111) at 90 and 300 K has been investig ated using ARUPS, HREELS and work-function measurements. Benzaldehyde adsor bs readily at both temperatures, with monolayer saturation reached at an ex posure of 1.4 L. Bonding occurs via the aldehyde functional group rather th an the ring pi electrons. At 90 K, the functional group remains intact, whi le at 300 K, the C=O bond breaks, forming direct covalent bonds to the meta l surface. At 90 K. the molecule lies flat, while at 300 K, the ring tilt d epends on coverage, with the saturated monolayer containing considerably mo re material than at 90 K. (C) 2000 Elsevier Science B.V. All rights reserve d.