Adsorption of polyfunctional 5-fluorouracil and 2,4-dithio-5-fluorouracil on Au(111) surface: Structure, energy, and electronic transmission

作者：Nazari Fariba^*; Ansari Narjes

来源：International Journal of Quantum Chemistry, 2012, 112(10): 2287-2293.

DOI：10.1002/qua.23214

• DFT
• 5-fluorouracil
• Au(111)
• DOS
• electronic transmission

Adsorption of 5-fluorouracil (5-FU) and 2,4-dithio-5-fluorouracil (2,4-DT-5-FU) on Au(111) surface at low coverage is studied by using periodic-slab-density functional theory calculation. Isolated 5-FU molecule adsorbs preferentially at bridge site in a vertical configuration via N?H group by forming the N?H...Au nonconventional H-bond. The formation of the anchor Au?O bond is not observed. Substitution of oxygen atoms of 5-FU with sulfur strongly influences the nature of adsorption and leads to the Au?S anchor bond and the N?H...Au nonconventional H-bond of single 2,4-DT-5-FU molecule on Au(111) surface. The adsorption site and orientation of 2,4-DT-5-FU molecule on the surface are similar to those of 5-FU. The metalmolecule coupling effects at asymmetric Au/S(N?H)S/mol/C?H/Au and Au/N?H/mol/O/Au transport junctions and symmetric Au/S(N?H)S/mol/mol/S(N?H)S/Au and Au/O/mol/mol/O/Au transport junctions are also investigated. The electronic structure is analyzed in detail, and the obtained results are used for illustrating the electron transmission in metalmoleculemetal systems.

• 出版日期2012-5-15