A new class of self-assembled monolayers on gold using an alkynyl group as a linker

The geometry and energetics for adsorption of ethynylbenzene on Au(111) have been studied using density functional theory. The alkynyl group, following removal of the terminal H atom, adsorbs covalently to the surface in the fee hollow site with a bond energy of about 70 kcal.mol^-1. Intermediate adsorption states are also possible via a hydrogen 1,2 shift to form a surface-bound vinylidene, or through the opening of the C-C triple bond without removing the hydrogen atom.