Ab initio quantum chemical design of supermolecule logical devices

Abstract

The geometrical structure of both the ground and excited state of the azo-dyes: Disperse Orange 3 (DO3) and Ch 2 - C 4 H 4 -N=N-C 44/H(subscript 4 -CH 2 molecules have been investigated applying the Hartree Fock (HF), density functional theory (DFT) methods with the Berny geometry optimization and Ames Laboratory determinant (ALDET)single- double-triple-quadra configuration interaction (SDTQ-CI) method. The investigations proved that the above-mentioned molecules can not rotate around the -N=N- bond. Thus, the alternative mechanism of the isomerization of the DO3 molecule per linear transition state has been suggested and investigated. The obtained one- and many- electron energy diagrams have been drawn. According to these diagrams the above mentioned isomerization way is possible. The mechanism of the isomerization of the azo-dyes molecule per linear transition state is suggested and investigated. The results of light induced internal molecular motions in azo-dyes molecules have been used for the design of light driven logically controlled molecular machines composed form photoactive organic molecules such as carbazole, 1,4- phenylenediamine (PhDA) and 4,5-dinitro- 9(dicyanomethylidene)-fluorene (DN9(CN) 2 F), Dithieno[3,2-b:2',3'-d]thiphene and Ferocene (C 10 H 10 Fe) molecules joined with -CH=CH- or -N=N- bridges. Ab initio DFT B3PW91 model using 6-311G** and Watanabe (WBTS) basis sets calculations show the stability of Sc 3 N and ErSc 2 molecules which exist inside endohedral fullerene C 80 derivatives: Sc 3 NC 80 . Analysis of electronic structure of inside clusters allowed proposing that these endohedral fullerenes might be used for electro- optical and magneto-optical switches and for information storage. We performed design of molecular logical devices based on organic electron donor and electron acceptor molecules, fullerene C 60 substituted derivative CH 2 C 60 , electron donor-bridge-electron acceptor dyads and triads. Design of new series molecular implementations (MI) of two variable logic functions: AND (NAND), OR (NOR) is based on geometry optimization procedure. Molecular triggers and molecular dynamic memory were designed based on investigations of photo-excitation movements and charge transfer of aza-fullerene supermolecule (NH 2 )CH-NC 59 -NC 59 -CH(NO 2 ). Our ab initio DFT B3PW91/LanL3DZ 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. 121