Photoswitching of Conductance through Salicylidene Methylamine

Abstract

Photoswitching of conductance through both stable isomers of salicylidene methylamine was investigated using nonequilibrium Green's function method combined with density functional theory. This study demonstrates how the optically induced intramolecular proton transfer between the hydroxyl group and the amino group of salicylidene methylamine can lead to molecular size photodiode with on/off current ratio of 1 order of magnitude. It was further elucidated that the optical switching alone is not sufficient to realize the molecular switch. Of primary importance was found to be the anchoring between the molecule and the metal electrodes. When the anchoring groups were connected to the benzene ring in para-orientation, minimal on/off current ratio was estimated. When the anchoring groups were connected to the benzene ring in meta-orientation, 1 order of magnitude on/off current ratio was calculated. Molecular orbital analysis was successfully employed to elucidate the difference in the photoswitching properties of the meta-and para-anchored isomers of salicylidene methylamine. This study demonstrates the potential application of aromatic Schiff bases as photodiodes in the field of molecular electronics.

Electronic and magnetic properties of the [Ni(salophen)]: An experimental and DFT study

“…As observed by Nijegorodov et al [1] , for a series of planar and non-planar molecules, due to the increment of the rigidity of the ligand after the coordination of the metal atom, the Stokes shift for [Ni(salophen)] is significantly lower (∼6000 cm −1 ) than the free basis ligand reported in Ref. [5] . Hence, the complex emission band appears at a lower wavelength than its free basis ligand.…”

“…Recently, there has been an increased interest in the chemistry of transition metal complexes containing N 2 O 2 coordination sites, such as salicylidenes [1] , due to their broad range of applications in areas such as catalysis [2] , functional materials, non-linear optics [3] , molecular magnetism [4] , and organic electronics [5] , such as light emitting diodes (OLEDs) [6] and display magnetic properties [7] . Among them, technologies based on light emission or charge transport abilities are currently receiving particular interest, leading to their use in electronic devices, such as solar cells and active components for image and data treatment storage [8] .…”

Enhancing the conductivity of molecular electronic devices

“…While not the first of its kind, [59][60][61] and most definitely not the first molecular switch proposed, 59 this hypothetical system is a rare example of a switch that does not exploit quantum interference in its switching mechanism (i.e., no transport channels canceling each other out). 62,63…”

Contacts for organic switches with carbon-nanotube leads

“…10,[37][38][39][40] Moreover, the properties of the junction may also depend on the CNT chirality, thus, all carbon electrodes considered in this work are of the zigzag type -the most effective form for the switches. 41 Following the work by Staykov et al, 30 we simulate transport in various structural connections to the leads: para, meta, and not studied earlier ortho -all displayed in Fig. 1.…”