The Role of the Charge State of the Molecule and the External Electric Field in the Functioning of Molecular Switches Based on Spiropyran Molecule

Authors Olha Kovalenko1, Petro O. Kondratenko2, Yuriy M. Lopatkin1

1Sumy State University, Rymsky-Korsakov, 2, 40007 Sumy, Ukraine

2National Aviation University, 1, Kosmonavt Komarov Prosp., 03680 Kyiv, Ukraine

Е-mail [email protected]
Issue Volume 10, Year 2018, Number 3
Dates Received 05 March 2018; published online 25 June 2018
Citation Olha Kovalenko, Petro O. Kondratenko, Yuriy M. Lopatkin, J. Nano- Electron. Phys. 10 No 3, 03023 (2018)
PACS Number(s) 31.10. + z, 31.15. – p, 31.15.bu, 33.15.Dj, 33.15.Hp,
Keywords Molecular switch, Transformation of molecules in an external electric field, Spiropyran, Merocyanine.   EE .

The geometric structure and energy of the electronic system of spiropyran and merocyanine molecules in electrically neutral form, as well as in cationic and anionic form in the presence of an external electric field (from – 0.02 a.u. to + 0.02 a.u.) were investigated using quantum mechanical methods. Spiropyran and merocyanine molecules with attached hydrogen atom to the oxygen and nitrogen atoms were also studied. It is shown that the attaching of a hydrogen atom to a nitrogen atom causes breaking of N-Cspiro bond and in the case of attaching to the oxygen Cspiro-O bond cleavage is observed. In both cases, such cleavage is accompanied by sp3 → sp2 rehybridization of the atomic orbitals of the spiro atom. It is shown that in the electric field E  +0.01 a.u. the right and left moieties simultaneously turned on 90°, breaking common -electronic system. It is discovered that in the electric field E  +(0.01-0.02) a.u. spiropyran molecule with attached hydrogen atom to the oxygen atom transforms into merocyanine molecule.

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