Quantum Chemical Design of Light Driven Molecular Logical Machines

Abstract

Density functional theory time dependent (Dfl-TD) model B3PW91\6-3I1G** calculations of azo-dye Disperse Orange 3 (D03) molecule show that in radiationless, first and fourth transitions, electron charge moves out from -N=N-bridge, which supports our recently found per linear trans-cis isomerization way. The results of light induced internal molecular motions in azo-dyes molecules have been used for the design and B3PW91-TD/6-3I1G** calculations of light driven logically controlled (OR function) molecular machine composed from organic photoactive electron donor molecule dithieno[3,2-b:2',3'-dlthiophene and electron accepting and moving part of D03 molecule. New fluorescing single supermolecular device was designed and its geometry optimization and electronic structure calculations were performed by Hartree-Fock (HF)/6-31 G method.

Quantum Mechanical Design of Molecular Computers Elements Suitable for Self-Assembling to Quantum Computing Living Systems

“…2) excited states are large enough and equal to 0.978 and 0.999 which is transfered from the ferrocene fragment to the azo-dye one. Oscillator strengths of these two transitions are weak also, while our found large (practically one electron) charge transfer and it location in this OR logically controlled molecular device indicate possibility of the movements such as observed in the case of an isolated Disperse Orange (DO3) molecule [1,2].…”

“…The bridge -N=N-in azo-dye molecules is rather flexible therefore all kinds of azo-dye molecules convert almost all photoexcitation energy to trans-cis isomerization energy [2,5,6]. We expect that in the case if our designed molecular OR logical gate, the photoinduced energy should be converted to movements of OR logic device due to cis-trans isomerization of azo dye [1,2].…”

“…Drawn in Fig. 1 OR molecular logical device is composed from good photo electron donors ferrocene and thiophene joined by bridges -CH=CH-to azo-benzene dye fragment phenyl-N=Nphenyl-NO 2 -should improve electron charge transfer value from ferrocene and thiophene branches in the selected excited states (it was weak charge transfer from NH 2 -phenyl-fragment [1,2]).…”

“…For example, valence electrons of molecules (which mainly determine features of nano-structures) possess strict quantum states, discrete quantum electronic, vibrational, NMR, EPR, etc spectra. Photoinduced electron charge transfer is going by quantum delocalized particle-wave trace (not like electrical current in present silicon-based PC computer chips) [1,2]. The study applied quantum mechanical ab initio and density functional theory-time dependent methods allow us to design light-driven, single supermolecular devices based on fullerene, biliverdin and photoactive molecules and Title of Publication (to be inserted by the publisher) supermolecules that could form basis for logically controlled organic molecular machines and gates of molecular electronics digital and quantum computers [1][2][3].…”

“…Quantum computing logic elements possess not only sixteen possible two variable logic functions (as it is in our designed gates of molecular electronics digital computers) [1][2][3] but significantly more ones due to accounting of the electron spin direction.…”