Experimental electronic structure of coordination compounds
- Jozef Kožíšek
- Talk , Chemical Bonding
- TBC
- TBC
Jozef Kožíšek, Lukáš Bučinský
Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava, Radlinského 9, Bratislava, SK-81237, Slovakia.
e-mail: jozef.kozisek@stuba.sk
Figure 1a Three-dimensional plot of the Lapacian of electron density around Pd at the iso-surface value of 120 e A-3, around O1, O2, O3 and O4 at the isosurface value of 40 e A-3 and the rest at the isosurface value of 15 e A-3
Figure 1b Static deformation desnity in the plane Pd–Pd*–H15. Contour spacing 0.025 e A-3, with positive contours drawn with a solid blue line and negative contours with a dashed red line. Symmetry code: *) 1–x, 1–y, 1–z
Thanks to the continuous improvement of single-crystal X-ray diffractometers and data processing software, it is expected that experimental electronic structures are approaching reality. However, we still see certain differences between experimental and theoretical results. The question arises as to which results are more correct. For the accuracy of the experimental study, we have certain parameters available, such as the crystallographic R-factor, residual electron density, error analysis using the fractal analysis [1], or the comparison of measured and calculated structural factors.
Chemical intuition plays an important role. In coordination compounds of Cu(II) complexes with the d9 electron configuration, the maximum number of electrons in each d-orbital cannot exceed value of 2.0, as we have shown in tetrakis(μ2-acetato)diaquadicopper(II) complex [2]. We have also shown the interaction of dz2 - dz2 orbitals. The same interaction we have studied in 1,10-phenanthroline-salicylatopalladium(II) monohydrate complex [3] (Figure 1a,1b). Another example of chemical intuition will be shown in 4-methyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]thiazole-2(3H)-thione [4].
Acknowledgement: We are grateful to Slovak Grant Agencies APVV (contract No. APVV-20-0213) and VEGA (1/0175/23).
References:
[1] Meindl, K. & Henn, J. (2008). Acta Cryst. A64, 404–418.
[2] Herich, P. et al., (2018). Acta Cryst. B74, 681–692.
[3] Varga, R. et al., (2024). In preparation.
[4] Vénosová, B. et al., (2020). Acta Cryst. B76, 450–468.
