ELECTRON AND ENERGY-TRANSFER THROUGH BRIDGED SYSTEMS .6. MOLECULAR SWITCHES - THE CRITICAL-FIELD IN ELECTRIC-FIELD ACTIVATED BISTABLE MOLECULES

In current discussions of molecular electronics, the possibility of employing weakly coupled symmetrical bistable molecules or ions which undergo configurational change under external perturbation as molecular switches in hypothetical logic or memory circuits is receiving special attention. For the particular case of switching by an externally applied electric field the parameters determining the critical field strength at which dipole reversal occurs, and methods of calculating it at the ab initio quantum chemical level are discussed, with particular reference to recent work of Aviram. It is shown that single-determinant SCF calculations employing the electronic aufbau principle can give rise to an artefactual result and may lead to code-dependent overestimation of the critical field strength by an order of magnitude. © 1990, American Chemical Society. All rights reserved.