The construction of devices based on molecular components depends upon the development of molecular wires with adaptable current–voltage characteristics. Here, we report that quantum interference effects could lead to substantial differences in conductance in molecular wires which include some simple polycyclic aromatic hydrocarbons (PAHs). For molecular wires containing a single benzene, anthr...

In the last chapter, we have been introduced to the three main ensembles used in statistical mechanics and some examples of calculations of partition functions were also given. In chemistry, we are concerned with a collection of molecules. If the molecules are reasonably far apart as in the case of a dilute gas, we can approximately treat the system as an ideal gas system and ignore the intermo...

Destructive quantum interference has been shown to strongly reduce charge tunneling rates across molecular bridges. The current consensus is that destructive quantum interference occurs in cross-conjugated molecules, while linearly conjugated molecules exhibit constructive interference. Our experimental results on photoinduced charge transfer in donor-bridge-acceptor systems, however, show that...

We theoretically demonstrate a strong dependence of the annihilation rate between (singlet) excitons on the sign of dipole-dipole couplings between molecules. For molecular H-aggregates, where this sign is positive, the phase relation of the delocalized two-exciton wave functions causes a destructive interference in the annihilation probability. For J-aggregates, where this sign is negative, th...

We study coherent phonon transport through organic, π-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features very analogous to those observed theoretically and experimentally for electron transport in simila...