On-Surface Alcohol\nFormation from a Carbene Precursor

A microscopic understanding of on-surface reactions involving\nhighly\nreactive intermediates is challenging because the intermediate quickly\nloses its reactivity after its creation via charge transfer from or\nto the surface. This binding to the surface competes with a bimolecular\nreactivity whenever the reaction partner is not in the immediate vicinity.\nIt is even more true for reactions involving more than two reaction\npartners, for instance, the synthesis of alcohol from a reaction of\na carbene with water, a reaction that involves three water molecules.\nWe demonstrate that fluorenol can be photolytically formed on a surface\nat low temperature from a carbene precursor 9-diazo fluorene with\nwater on Ag(111) using scanning tunneling microscopy and density functional\ncalculation. At an excess of water, the precursor reacts with water\nto fluorenol at a temperature as low as 80 K. The same reaction is\ninduced at 11 K via ultraviolet photolysis of the precursor bonded\nin inverse solvent–solute complexes to fractal water islands.\nOur study demonstrates that complex on-surface reactions, including\nseveral water molecules, are feasible with a carbene as a highly reactive\nintermediate despite its high affinity to electrons drawn from the\nmetal surface.