Electron tunneling, charge transfer, and the intermolecular forces between two H2 molecules

Electron transfer between biological molecules by thermally activated tunneling.

A theory of electron transfer between two fixed sites by tunneling is developed. Vibronic coupling in the individual molecules produces an activation energy to transfer at high temperatures, and temperature-independent tunneling (when energetically allowed) at low temperature. The model is compared with known results on electron transfer in Chromatium and in Rhodopseudomonas spheroides. It quan...

Tunneling between parallel two-dimensional electron gases.

The tunneling between two parallel two-dimensional electron gases has been investigated as a function of temperature T , carrier density n, and the applied perpendicular magnetic field B. In zero magnetic field the equilibrium resonant lineshape is Lorentzian, reflecting the Lorentzian form of the spectral functions within each layer. From the width of the tunneling resonance the lifetime of th...

Electron tunneling in biological molecules*

Electron transfers in photosynthesis and respiration commonly occur between protein-bound prosthetic groups that are separated by large molecular distances (often greater than 10 AÊ ). Although the electron donors and acceptors are expected to be weakly coupled, the reactions are remarkably fast and proceed with high speci®city. Tunneling timetables based on analyses of Fe/Cu to Ru electron-tra...

The nature of aqueous tunneling pathways between electron-transfer proteins.

Structured water molecules near redox cofactors were found recently to accelerate electron-transfer (ET) kinetics in several systems. Theoretical study of interprotein electron transfer across an aqueous interface reveals three distinctive electronic coupling mechanisms that we describe here: (i) a protein-mediated regime when the two proteins are in van der Waals contact; (ii) a structured wat...

Charge fluctuations in single-electron tunneling oscillations