Binding of Zwitterionic Ruthenium(III) Complexes with Cucurbit[7]urils in Solution


        Sanaz Malali,^†,$ Jan Chyba,^† Michal Knor,^†,$ Jan Novotný,^†,‡ Radek Marek*^†,‡,$


^† CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500
Brno, Czechia

^$ Department of Chemistry and ^‡ National Center for Biomolecular Research, Faculty of Science,
Masaryk University, Kamenice 5, CZ-62500 Brno, Czechia


Paramagnetic ruthenium(III) compounds have been investigated as anticancer metallodrugs  in past
two decades.^1 In this work, we analyze a new class of zwitterionic paramagnetic Ru-based complexes
containing cyclohexyl or adamantyl anchors. The ultimate goal of this study is to clarify their
binding with cucurbit[7]uril (CB7) cavitand in solution.

The structures of Ru coordination compounds and their Rh analogs were characterized by 1D and 2D
NMR experiments including temperature-dependent measurements to break the total NMR shift down to
the orbital and hyperfine contribution.^2 The experimental observations were complemented by the
relativistic density functional theory (DFT) calculations to investigate the host-guest behavior
and effect of paramagnetic center on the NMR chemical shifts of CB7 cavitand.^3


Acknowledgment: This project has received funding from the Czech Science Foundation (grant number
18-05421S).


References:

1.      L. Zeng, P. Gupta, Y. Chen, E. Wang, L. Ji, H. Chao, Z.S. Chen: Chem. Soc. Rev., 2017, 46,
5771.

2.      J. Novotný, M. Sojka, S. Komorovsky, M. Nečas, R. Marek: J. Am. Chem. Soc., 2016, 138,
8432.

3.      J. Chyba, M. Novák, P. Munzarová, J. Novotný, R. Marek: Inorg. Chem., 2018, 57, 8735.