Inorganic & Coordination Chemistry, Poster
IC-156

Synthesis and isolation of previously infeasible dithiolato bridged dinuclear ruthenium complexes [(p-MeC6H4iPr)2Ru2SR2Cl2] using optimized reaction conditions

 

H. Primasova1, M. De Capitani1, I. Gjuroski1, J. Furrer1*
1Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland

It is well known that the dimer p-cymene-ruthenium dichloride [(p-MeC6H4iPr)2Ru2(m-Cl)2Cl2] reacts with aromatic thiols to give cationic trithiolato complexes [(p-MeC6H4iPr)2Ru2(SR)3]+ [1]. The reaction proceeds through neutral dithiolato intermediates [(p-MeC6H4iPr)2Ru2(SR)2Cl2], some of which could be isolated in good yields [2]. From our previous studies, a perquisite for the successful isolation of dithiolato intermediates was that the thiol must be aliphatic, otherwise the reaction cannot be controlled and leads immediately to the corresponding cationic trithiolato complexes [3].

Herein, we report the synthesis of new dithiolato complexes [(p-MeC6H4iPr)2Ru2(SR)2Cl2] with aromatic thiols (R=p-t-Bu-Ph: 1; p-MeO-Ph: 2; p-Br-Ph: 3) in good  to excellent yields  and sufficient level of purity for 1 and 2. The complexes could be obtained using optimized conditions (DCM, 4h, 0-25°C).

Despite being generally biologically less active then their corresponding trithiolato counterparts, dithiolato intermediates can be further functionalized with a different thiol, R2, giving a mixed trithiolato complexes [(p-MeC6H4iPr)2Ru2(SR2)(SR)2]+ which are known to be highly cytotoxic against cancer cells [4].  Depending on the nature of R2, the complexes can be further functionalized with bioactive molecules, thus strongly increasing the chemical variability and the bioactivity of the complexes [5]. As such, the present work represents the first step of our general goal which is to synthesize numerous new ruthenium conjugates with different properties.

 

[1] J. Furrer and G. Süss-Fink, Coord. Chem. Rev., 2016, 309, 36–50.
[2] A.-F. Ibao, M. Gras, B. Therrien, G. Suess-Fink, O. Zava, and P. J. Dyson,  Eur. J. Inorg. Chem., 2012, 2, 1531–1535.
[3] M. A. Furrer, A. Garci, E. Denoyelle-Di-Muro, P. Trouillas, F. Giannini, J. Furrer, C. M. Clavel, P. J. Dyson, G. Süss-Fink, and B. Therrien, 2013,  Chem. - A Eur. J., 19, 3198–3203.
[4] F. Giannini, J. Furrer, G. Suss-Fink, C.M. Clavel, P.J. Dyson, J. Organomet. Chem., 2013, 744, 41-48.
[5] F. Giannini, M. Bartoloni, L.E.H. Paul, G. Suss-Fink, J.-L. Reymond, J. Furrer, MedChemComm, 2015, 6, 347-350.