Quantum Mechanical ab initio Investigations of Fullerene and Photoactive Molecules, Supramolecules, Supermolecules and Design of Molecular Logical Devices

A. Tamulis^{*, a}, J. Tamuliene^{a}, V. Tamulis^{b}, and N. A. Kotov^{c}

^{a}Institute of Theoretical Physics and Astronomy,
A. Gostauto 12, 2600 Vilnius, Lithuania ^{b}Faculty of Natural Sciences, Vilnius University M.K. Ciurlionio 21/27, Vilnius, Lithuania ^{c}Department of Chemistry, Oklahoma State University Stillwater, Oklahoma 74078, USA

Quantum chemical ab initio calculations and investigations were performed on three photo electron donor molecules: carbazole (abbreviation of this compound will be Cz and formula is C_{12}H_{9}N), N,N,N',N'-tetramethyl-1,4-phenylene-diamine (abbreviation: TeMePhDA, formula: C_{6}H_{4}(N(CH_{3})_{2})_{2}), 1,4-phenylenediamine (PhDA, C_{6}H_{4}(NH_{2})_{2}); several organic electron acceptor molecules: 2,4,7-trinitro-9-fluorenone (TNF, C_{12}H_{5O}(NO_{2})_{3}), 2,4,5,7-tetranitro-9-fluorenone (TeNF, C_{12}H_{4O}(NO_{2})_{4}), 7,7,8,8- tetra-cyano-quino-dimethane (TCNQ, C_{8}H_{4}(CN)_{4}), 2,4,7-trinitro-9-dicyano-fluorene (TN9(CN)_{2}F, C_{12}H_{5}C(CN)_{2}(NO_{2})_{3}), 2,4,5,7-tetranitro-9-dicyano-fluorene (TeN9(CN)_{2}F, C_{12}H_{4}C(CN)_{2}(NO_{2})_{4}), 1,2,4,5-tetra-cyano-benzene (TCNB, C_{6}H_{2}(CN)_{4}), 2,3,5,6-tetrachlor-1,4-benzoquinone (TeClBQ, C_{6}Cl_{4}O_{2}), 2,3,5,6-tetrafluoro-7,7,8,8-tetra-cyano-quino-dimethane (TeFTCNQ, C_{8}F_{4}(CN)_{4}); empty and endohedral fullerene C_{20+2n} (n= 0, 2, 3, ..., 16) molecules; electron donor - containing supermolecules (electron donors are connected via the electron insulator bridges with electron acceptor molecules) and electron donor - containing supramolecules (electron door and electron acceptor molecules are stabilised by the van der Waals forces) were performed using Hartree-Fock (HF), MP2 and density functional theory methods. After the geometry optimization in ground state it were used ab initio and semiempirical methods CNDO/S-CI, ZINDO-CI methods for the calculation of the excited states. The results of our investigations show that photoactive charge transfer electron donor-containing supermolecules and supramolecules should be molecular implementation of photodiodes. The quantum mechanical investigations of fullerene C_{24}, C_{26}, C_{28} molecule conformers are performed in the framework of point set group theory and semiempirical PM3 configuration interaction, MNDO, AM1 and HF methods. The main criterion of stability of calculated fullerene molecules we stated the lowest total energy of various isomers and conformers that appears due to the Jahn-Teller distortion. The most stable occurs C_{24} D_{6} symmetry conformation with term and open shell C_{26} D_{3h} symmetry conformation with term .

Molecular Implementation (MI) of two, three, four variable logic functions, summators of neuromolecular networks, cells of molecular cellular automata, molecular trigger - molecular logic devices were designed based on results of semiempirical quantum chemical calculations of above mentioned electron donor, electron insulator, electron acceptor and fullerene molecules. Complete set of sixteen MIs of two variable logic functions (for example: OR, AND, Implication, Equivalence, Difference, etc.) was designed and also proposed using MIs of two variable molecular logic function initial basic sets: {OR, AND, Negation} or {NOR} and, or {NAND}. We have described in more detail the designed MIs of: a) two variable logic functions OR, NOR, AND, NAND (from fullerene molecules) ,Converse Unitary Negation-1, Converse Unitary Negation-0, Unitary Negation-1, Unitary Negation-0, "0" and "1" Matrix Constants; b) three variable logic functions AND, NAND, OR, NOR analogs; c) four variable logic functions OR, NOR, AND, NAND analogs. The electron hoping via the insulator bridges in the supermolecules: electron donor-bridge-electron acceptor phenomenon was investigated by using CNDO/S-Configuration Interaction method.

We are investigating in more detail the electronic structure of above mentioned planar electron donor and electron acceptor molecules, series of fullerene C_{60} substituted derivatives: C_{60}CH_{2}, C_{60}C_{2}H_{4}, C_{60}C_{3}H_{6}, C_{60}C_{4}H_{8}, electron donor-bridge-electron acceptor diodes, and triodes using ab initio MP2, HF and DFT methods and designing new series of more correctly MIs of two variable logic functions: OR, NOR, AND, NAND (two sets: one designed from planar molecules and another - from fullerene molecules),Converse Unitary Negation-1, Converse Unitary Negation-0, Unitary Negation-1, Unitary Negation-0, "0" and "1" Matrix Constants based on geometry optimization procedure and excited states molecular logic devices.

^{*}Corresponding Address:
Arvydas Tamulis
Institute of Theoretical Physics and Astronomy, Theoretical Molecular Electronics Research Group
A. Gostauto 12, Vilnius 2600, Lithuania
Phone: +(370-2)-620861; fax: +(370-2)-225361 or +(370-2)-224694
e-mail: TAMULIS@ITPA.lt; WEBsite: http://www.itpa.lt/~tamulis/