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DFT Calculations of the Electric Field Gradient at the Tin Nucleus as a Support of Structural Interpretation by 119 Sn Mössbauer Spectroscopy
Author(s) -
Barone Giampaolo,
Silvestri Arturo,
Ruisi Giuseppe,
La Manna Gianfranco
Publication year - 2005
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200401156
Subject(s) - electric field gradient , quadrupole , quadrupole splitting , tin , mössbauer spectroscopy , zeeman effect , analytical chemistry (journal) , chemistry , mössbauer effect , spectroscopy , atomic physics , physics , nuclear magnetic resonance , crystallography , magnetic field , organic chemistry , quantum mechanics , chromatography
DFT calculations, using an all‐electron basis set and with full geometry optimization, were performed on 34 Sn II and Sn IV compounds of known structure and 119 Sn Mössbauer parameters, to obtain the theoretical values of the electric field gradient components, V xx , V yy , and V zz , at the tin nucleus. These were used to determine the quantity V = V zz ${\bigg[}$ 1+ ${{1\over 3}}$ ${\bigg(}$ ${{V{_{xx}}- V{_{yy}}\over V{_{zz}}}}$ ${\bigg)}$ 2 ${\bigg]}$ 1/2 , for each investigated compound, which is related to the quadrupole splitting (Δ E ) parameter according to Δ E =1/2 eQV , where e is the electronic charge and Q is the quadrupole moment of the tin nucleus. The linear fitting of the correlation plot of the experimental Δ E , versus the corresponding calculated V values, produced a slope that is equal to 0.93±0.03 and a correlation coefficient R =0.982. The value of Q obtained, 15.2±4.4 fm 2 , is in agreement with that previously experimentally determined or calculated by analogous procedures. The calculation method is able to establish the sign of the electric field gradient component V zz , in agreement with the sign of Δ E determined experimentally by Mössbauer–Zeeman spectroscopy. The calculated structural parameters are in good agreement with the corresponding experimental data, determined by X‐ray crystallography in the solid state, with average structural deviations of about 3 % for bond lengths and angles in the tin environment. Calculated values of Δ E were obtained from the calibration fitting constant and from the values of V . By comparing experimental and calculated Δ E parameters, the structure assignment of configurational isomers was successful in two test cases, in agreement with the experimental X‐ray crystallographic structures. These results indicate that the method can be used as a tool to support the routine structure interpretation of tin compounds by 119 Sn Mössbauer spectroscopy.