title: Rotational Spectromicroscopy: Imaging the Orbital Interaction between Molecular Hydrogen and an Adsorbed Molecule.
abstract: A hydrogen molecule can diffuse freely on the surface and be trapped above an adsorbed molecule within the junction of a scanning tunneling microscope. The trapped dihydrogen exhibits the properties of a free rotor. Here we show that the intermolecular interaction between dihydrogen and Mg-porphyrin (MgP) can be visualized by imaging j=0 to 2 rotational excitation of dihydrogen. The interaction leads to a weakened H-H bond and modest electron donation from the dihydrogen to the lowest unoccupied molecular orbital of MgP, a process similarly observed for the interaction between dihydrogen and an adsorbed Au atom.
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.
authors.forename: Shaowei
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.|College of Materials Science and Engineering, Hunan University, ChangSha 410082, China.
authors.forename: Dingwang
authors.initials: D
authors.lastname: Yuan
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Yu
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Czap
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.
authors.forename: Ruqian
authors.initials: R
authors.lastname: Wu
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.|Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
authors.forename: W
authors.initials: W
authors.lastname: Ho
mesh_terms: D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling / Q000379:methods; D008956:Models, Chemical; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D011166:Porphyrins; D006859:Hydrogen; D008274:Magnesium; D000537:Aluminum Oxide