Density Functional Theory (DFT) B3PW91-TD\6-311G** model calculations of azo-dye disperse Orange 3 (DO3) molecule charge transfer indicate that in radiationless transitions charge move out from -N=N- bridge that support per linear isomerisation way [1, 2]. The results of light induced internal molecular motions in azo-dyes molecules have been used for the design and B3PW91-Time Dependent (TD)/6-311G** calculations of light driven OR logically controlled molecular machines composed from photoactive organic molecules such as electron donor: dithieno[3,2-b:2',3'-d]thiophene and ferocene (C10H10Fe) and electron accepting and moving part of DO3 molecule. Applied DFT-TD method and our visualization program showed from which fragments electron is hopping in various excited states . Further development of molecular machines are performing using B3PW91\6-311G** geometry optimization of larger molecular robots possessing efficient fluorescence (Fluorescein-DO3) and anti-oxidant biological activity (Biliverdin CuOEB-DO3) and searching the charge transfer of these molecular devices in different excited states using B3PW91\6-311G**-TD. Calculation results allow to predict molecular devices with stable electronic structure and choose devices with optimal features of fluorescencing and anti-oxidant activity that makes able to use them in sensitive nano-structured organic and biological sensors.
We have performed design and Hartree-Fock (HF) 6-31G single point calculations of molecular logical devices based on organic electron donor: dithieno[3,2-b:2',3'-d]thiophene, ferocene (C10H10Fe) and electron acceptor molecules: 1,3-bis(dicyanomethylidene)indane, fullerene C60 substituted derivative CH2CH2NHC60 and electron donor-bridge-electron acceptor dyads and triads including electron donor and acceptor molecules joined with -CH=CH- bridge [1, 2]. Further design of series molecular implementations of two variable logic functions: AND (NAND), OR (NOR), etc. is based on quantum chemical ab initio HF/6-311G** geometry optimization procedure which allow to predict stability of our newly designed logical gates based on C60 substituted derivatives CH2CH2NHC60 and CH2C60. The most stable molecular logic gates are investigating using B3PW91\6-311G**-TD method searching for charge transfer in various excited states.
Our DFT B3PW91/LanL2DZ calculation of HOMO-LUMO gap in CdS nanocluster without four phenyle fragments gives value equal to 3.85 eV and the same method calculation of CdS nanocluster with four phenyle fragments gives HOMO-LUMO gap value equal to 3.66 eV. The attachment of organic molecules to CdS nanocluster reduces HOMO-LUMO gap that allow to make more sensitive nano-electronic devices . Based on these investigations it is performing HF/6-311G** geometry optimization of photoactive charge transfer nano device: thiophene - CdS nanocluster - TCNQ and searching for charge transfers in various excited states using B3PW91G**-TD.
First principles quantum chemical B3PW91\6-311G** design of quantum computers elements generating from one to six qubits are started basing on series Cu, Fe or Co biliverdin derivatives replacing hydrogen atoms by Cl, F or Br atoms. There are performing Nuclear Magnetic Resonance (NMR) calculations of series Cu, Fe or Co biliverdin derivatives and other paramagnetically 1H shifted derivatives in order to find quantum computer elements with broad NMR spectra for good Quantum Bits resolution.
Theoretical Molecular Electronics Research Group
Institute of Theoretical Physics and Astronomy,
A. Gostauto 12, Vilnius 2600, Lithuania
Email: firstname.lastname@example.org http://www.itpa.lt/~tamulis/