@article{17979,
  abstract     = {Using scanning tunneling microscope break-junction experiments and a new first-principles approach to conductance calculations, we report and explain low-bias charge transport behavior of four types of metal–porphyrin–gold molecular junctions. A nonequilibrium Green’s function approach based on self-energy corrected density functional theory and optimally tuned range-separated hybrid functionals is developed and used to understand experimental trends quantitatively. Importantly, due to the localized d states of the porphyrin molecules, hybrid functionals are essential for explaining measurements; standard semilocal functionals yield qualitatively incorrect results. Comparing directly with experiments, we show that the conductance can change by nearly a factor of 2 when different metal cations are used, counter to trends expected from gas-phase ionization energies which are relatively unchanged with the metal center. Our work explains the sensitivity of the porphyrin conductance with the metal center via a detailed and quantitative portrait of the interface electronic structure and provides a new framework for understanding transport quantitatively in complex junctions involving molecules with localized d states of relevance to light harvesting and energy conversion.},
  author       = {Liu, Zhen-Fei and Wei, Sujun and Yoon, Hongsik and Adak, Olgun and Ponce, Ingrid and Jiang, Yivan and Jang, Woo-Dong and Campos, Luis M. and Venkataraman, Latha and Neaton, Jeffrey B.},
  issn         = {1530-6992},
  journal      = {Nano Letters},
  number       = {9},
  pages        = {5365--5370},
  publisher    = {American Chemical Society},
  title        = {{Control of single-molecule junction conductance of porphyrins via a transition-metal center}},
  doi          = {10.1021/nl5025062},
  volume       = {14},
  year         = {2014},
}