Download Main field of study: 011200 Physics

Main field of study: 011200 Physics
Area of specialization: 21 Photonics of Heterogeneous and Condensed Systems
Department of Photonics
Scientific advisor: Candidate of Science Physics and Mathematics, Litke S. V.
Reviewer: Candidate of Science Physics and Mathematics, Krauklis I. V.
Quantum-chemical investigation of bis-bipyridyl chloro- and nitro-complexes
of ruthenium (II) with 4-substituted pyridine ligands
Reshetova Kristina Igorevna
Luminescence and excitation of luminescence spectra of the freezed (77 K) alcohol
solutions of the polypyridine complexes of ruthenium (II): cis-[Ru(bpy)2(L)(NO2)]+ (bpy – 2,2´bipyridyl, L – pyridine, 4-cyanopyridine, 4-aminopyridine, isonicotinamide, 4-picoline, 4,4'bipyridyl, trans-1,2-bis(4-pyridyl)ethylene, pyrazine and Me2N-Py) have been measured. A
linear correlation between the energy of a metal-to-ligand charge transfer triplet (3MLCT)
electronically excited state and the values of pKa of free ligands L were revealed.
A quantum-chemical calculations were performed using Gaussian 09 to investigate the
electronic structure of a above-mentioned nitro-complexes and related chloro-complexes of Ru
(II) with the same ligands L. Calculations were performed within the bounds of DFT, using 631G(d) and LanL2DZ basis. A geometry optimization, frequency analysis, single-point energy
calculations and excited state calculations using the time-dependent DFT method were realized.
A quantum-chemical calculation results are in good agreement with experimental data. In
both series of the complexes there is a linear correlation between the energy of 3MLCT state and
a charge value of nitrogen atom of pyridine ring of ligand L. The charge is unambiguously
related to the value of pKa of free ligand L. In accordance with Ligand Field Theory the energy
of dπ-orbital of Ru(II) ion depends on a charge values of inner coordination sphere ligands of
complexes. The variation of dπ-orbital energy leads to a variation of energy of 3MLCT state.
The overall displacement of 3MLCT state energy comes to 2000 cm-1 between chloro- and
nitro-complexes. In spite of the fact a difference between proportionality coefficients of above
mentioned linear approximations is less than 10%. On a basis of the results one can suggest an
additive nature of ligand influence on electronic structure of complexes of ruthenium (II).
List of Publications:
Reshetova Ch. I. Abstract of the report «Quantum-chemical investigation of the Ru (II)
cloro-bis(bipyridyl) complexes with substituted pyridine ligands» // International Students
Conference "Science and Progress", p. 123, November 12—16, 2012, St. Petersburg — Peterhof