Stabilization of dichalcogenide ligands in the coordination sphere of a ruthenium system

Koushik Saha (1) , Sourav Gayen (1) , Urminder Kaur (1) , Thierry Roisnel (2) , Sundargopal Ghosh (1)

1 IIT Madras - Indian Institute of Technology Madras
2 ISCR - Institut des Sciences Chimiques de Rennes

The synthesis, structure and electronic properties of tetraruthenium dichalcogenide complexes displaying the exclusive coordination mode of dichalcogenide ligands have been discussed. The reactions of Li[BH2E3] (E = S or Se) with [ClRu(mu-Cl)(p-cymene)](2) (p-cymene = eta(6)-{p-C6H4(Pr-i)Me}) at room temperature yielded tetrametallic dichalcogenide complexes [{Ru2Cl2(p-cymene)(2)}(2)(mu(4),eta(2)-E-2)], 1-2 (E = S (1) and Se (2)). The solid-state X-ray structure of 1 shows that two {(p-cymene)RuCl}(2) moieties are bridged by a S-S bond. In addition to 2, the reaction of Li[BH2Se3] with [ClRu(mu-Cl)(p-cymene)](2) also yielded a mononuclear tris-homocubane analogue [Ru(p-cymene){Se-7(BH)(3)}] (3) which is an analogue of 1,3,3-tris-homocubane and possesses D-3 symmetry. In order to isolate the Cp* analogue of 1, the reaction of [Cp*Ru(mu-Cl)Cl](2) with Li[BH2S3] was carried out, which led to the formation of bis/tris-homocubane derivatives [(Cp*Ru)(2){mu-S-n(BH)(2)}] (n = 7 (4) and 6 (5)) along with the formation of ruthenium disulfide complexes [(RuCp*)(2)(mu,eta(2):eta(2)-S-2)(mu,eta(1):eta(1)-S-2)] and [(RuCp*)(2)(mu-SBHS-kappa B-1:kappa S-2:kappa S-2)(mu,eta(1):eta(1)-S-2)]. Complexes 1-5 have been characterized by multi-nuclear NMR, IR, UV-vis spectroscopy, and mass spectrometry and their molecular formulations (except 2) have been determined by single crystal X-ray crystallography. Furthermore, DFT calculations were performed that rationalize the stabilization of the dichalcogenide units (E-2(2-)) by the tetrametallic systems in 1-2.

Domaines: Chimie

Koushik Saha, Sourav Gayen, Urminder Kaur, Thierry Roisnel, Sundargopal Ghosh. Stabilization of dichalcogenide ligands in the coordination sphere of a ruthenium system. Dalton Transactions, 2021, 50 (37), pp.12990-13001. ⟨10.1039/d1dt01614h⟩. ⟨hal-03331393⟩