New ruthenium(II) precursors with the tetradentate sulfur macrocycles tetrathiacyclododecane ([12]aneS4) and tetrathiacyclohexadecane ([16]aneS4) for the construction of metal-mediated supramolecular assemblies

Modulating the electron-transfer properties of a mixed-valence system through host–guest chemistry

“… 27 Furthermore, despite the huge activity in this area, reports on metallomacrocycles containing ruthenium moieties are relatively rare, whilst only a handful of MV systems have been reported – reflecting the kinetically inert nature of such centres. 28 – 32 …”

The Pivotal Role of Ru‐dmso Compounds in the Discovery of Well‐Behaved Precursors

“…chel = en, dach, bpy, pic, acac, ox, mal; L = Cl – , dmso‐S, py, Im; X = Cl, CF 3 SO 3 , PF 6 ; n = 0–2). Depending on the nature of the ligands, these compounds can be prepared either directly from 22 in a two‐step synthetic procedure (see Figure for the case of neutral N–N ligands) or through the versatile and more reactive “second generation” precursors, [RuCl([9]aneS 3 )(dmso‐S) 2 ][X] ( 29 ) and [Ru([9]aneS 3 )(dmso‐O)(dmso‐S) 2 ][X] 2 ( 30 ) (X = CF 3 SO 3 , PF 6 ), obtained from 22 upon silver‐assisted replacement of one or two chlorides, respectively, with dmso (Figure ) , , . Interestingly, when 30 was compared with the isostructural complex [Ru([9]aneS 3 )(CH 3 CN) 3 ] 2+ , NMR investigations showed that in coordinating solvents such as water the coordinated dmso ligands are much more labile than acetonitrile …”

“…Consistent with this hypothesis, we also found that upon increasing the number of sulfur atom in the macrocycle from three to four, the affinity of Ru II for additional dmso ligands decreases. In fact, whereas treatment of 1 with the tetradentate sulfur macrocycle 1,4,7,10‐tetrathiacyclododecane ([12]aneS 4 , Figure ) afforded the cationic complex with one residual dmso cis ‐[Ru([12]aneS 4 )(dmso‐S)Cl]Cl ( 24 ), the larger and more flexible macrocycle 1,5,9,13‐tetrathiacyclohexadecane ([16]aneS 4 , Figure ) yielded the neutral compound cis ‐[Ru([16]aneS 4 )Cl 2 ] ( 25 ) …”

“…Remarkably, treatment of 26 with pyrazine under different conditions always afforded – upon replacement of the labile aqua ligand – the molecular triangle [{ cis ‐Ru([12]aneS 4 )(µ‐pyz)} 3 ](CF 3 SO 3 ) 6 ( 28 ) (in small yield), whose X‐ray structure was also determined …”

Synthetic strategies towards ruthenium–porphyrin conjugates for anticancer activity

“…12), in which the peripheral Ru fragments have no labile ligands, was prepared in good yield by reaction of bpy 4 -PP with a slight excess of the Ru(II) precursors [Ru( [12]aneS4)(dmso-S)(H 2 O)][CF 3 SO 3 ] 2 ([12]aneS4 = 1,4,7,10-tetrathiacyclododecane). 41 We also prepared the corresponding model complex [Ru( [12]aneS4)(bpyAc)][CF 3 SO 3 ] 2 (12) as a reference for NMR purposes. The downfield region of the 1 H NMR spectrum of 11 in deuterated acetone or nitromethane is similar to that of 9, with the additional feature that, beside the bH resonance, also the doublets of H6 and H6¢ are quite broad at 20 • C (Fig.…”