Süss-Fink, Georg

2014, Raja, Mathiyazhagan Ulaganatha, Tauchman, Jiri, Therrien, Bruno, Süss-Fink, Georg, Riedel, Tina, Dyson, Paul J.

The non-steroidal anti-inflammatory and anti-arthritic drug piroxicam (LH) reacts with arene ruthenium dichloride dimers in refluxing dichloromethane to give the complexes [(?6-arene)Ru(?2-N,O-L)Cl] (3: arene = C6H5Me, 4: arene = p-MeC6H4Pri, 5: arene = C6Me6). The reaction seems to proceed via the intermediates [(?6-arene)Ru(N-LH)Cl2], which can be obsd. for arene = C6H5Me (1) and isolated in the case of arene = p-MeC6H4Pri (2). The analogous reaction with pentamethylcyclopentadienyl rhodium and iridium gives the complexes [(?5-C5Me5)M(?2-N,O-L)Cl] (6: M = Rh, 7: M = Ir). The single-crystal x-ray structure analyses of the p-cymene ruthenium derivs. 4 and 2 show the metal atom in the archetypical piano stool geometry; in 4 the piroxicamato ligand is coordinated in a bidentate fashion through the pyridine nitrogen atom and the enolic oxygen atom, while in 2 the intact piroxicam ligand is coordinated in a monodentate fashion through the pyridine nitrogen atom. The piroxicamato complexes 3-5 are weakly cytotoxic towards human ovarian cancer cells. [on SciFinder(R)]

2013, Gupta, Gajendra, Garci, Amine, Murray, Benjamin S., Dyson, Paul J., Fabre, Gabin, Trouillas, Patrick, Giannini, Federico, Furrer, Julien, Süss-Fink, Georg, Therrien, Bruno

Neutral dinuclear dithiolato-bridged pentamethylcyclopentadienyl Rh(III) complexes (C5Me5)2Rh2(?-SR)2Cl2 (R = CH2Ph, 1; R = CH2CH2Ph, 2) and cationic dinuclear trithiolato-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) complexes [(C5Me5)2M2(?-SR)3]+ (M = Rh, R = CH2Ph, 3; M = Rh, R = CH2CH2Ph, 5; M = Rh, R = CH2C6H4-p-tBu, 7: M = Ir, R = CH2Ph, 4; M = Ir, R = CH2CH2Ph, 6; M = Ir, R = CH2C6H4-p-tBu, 8) were synthesized from the chloro-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) dimers (C5Me5)2M2(?-Cl)2Cl2 by reaction with the corresponding thiol deriv. (RSH). Complexes 3-8 were isolated as chloride salts. All complexes were obtained in good yield and were fully characterized by spectroscopic methods. The mol. structures of the neutral complexes (1 and 2) show interesting features: the two Rh atoms are bridged by two thiolato ligands with no metal-metal bonds and the pentamethylcyclopentadienyl and chlorido ligands are oriented syn to each other, an uncommon conformation for such dinuclear complexes. These structural features were rationalized using DFT calcns. Addnl., the antiproliferative activity of the complexes was evaluated against the cancerous A2780 (cisplatin sensitive) and A2780cisR (cisplatin resistant) human ovarian cell lines and on the noncancerous HEK293 human embryonic kidney cells. All complexes are active and the cationic Ir complexes 4, 6 and 8 are particularly cytotoxic, with IC50 values in the nanomolar range (IC50 < 0.1 ?M). The catalytic activity of the complexes for the oxidn. of glutathione (GSH) to GSSG was evaluated by NMR spectroscopy. [on SciFinder(R)]

2013, Giannini, Frederico, Furrer, Julien, Süss-Fink, Georg, Clavel, Catherine M., Dyson, Paul J.

2012, Tauchman, Jiri, Therrien, Bruno, Süss-Fink, Georg, Stepnicka, Petr

Three series of heterodinuclear Ru-Fe complexes were synthesized from (?6-arene)ruthenium dichloride dimers and phosphinoferrocene ligands contg. glycine-based carboxamido substituents. The neutral complexes [(?6-arene)RuCl2(Ph2PfcCONHCH2CO2Me-?P)] (4, arene = benzene (a), p-cymene (b), hexamethylbenzene (c); fc = ferrocene-1,1'-diyl) were obtained by the bridge cleavage reaction of [(?6-arene)RuCl2]2 with Ph2PfcCONHCH2CO2Me (1) in CHCl3 soln. [(?6-P-cymene)RuCl2(Ph2PfcCONHCH2CONH2-?P)] (6b) was synthesized in the same way from Ph2PfcCONHCH2CONH2 (3); the prepn. of [(?6-p-cymene)RuCl2(Ph2PfcCONHCH2CO2H-?P)] (5b), featuring the ferrocene ligand in the free acid form (2), failed due to side reactions and isolation problems. [(?6-Arene)RuCl(MeCN)(1-?P)][PF6] (7a-c) and [(?6-arene)Ru(MeCN)2(1-?P)][PF6]2 (8a-c) were prepd. from 1 and the MeCN precursors [(?6-arene)RuCl(MeCN)2][PF6] and from 4a-c via halide removal with Ag[PF6] in MeCN soln., resp. Alternative synthetic routes to 7b and 8b were also studied. The compds. were fully characterized by elemental anal., multinuclear NMR, IR, and electrospray ionization mass spectra, and their electrochem. properties were studied by cyclic voltammetry at a Pt-disk electrode. The single-crystal x-ray analyses of two representatives (4b and 8b) revealed a pseudotetrahedral coordination geometry at the Ru centers and eclipsed conformations of the ferrocene moieties, with the substituents at the two cyclopentadienyl rings being anti with respect to each other. All complexes showed high activity for the catalytic oxidn. of secondary alcs. with tert-Bu hydroperoxide to give ketones in aq. media. The most active catalyst was obtained from the neutral p-cymene complex 4b, showing a catalytic turnover frequency of 13,200 h-1 at room temp. for the oxidn. of 1-phenylethanol at a substrate/catalyst ratio of 100,000. [on SciFinder(R)]

2013, Giannini, Federico, Paul, Lydia E. H., Furrer, Julien, Therrien, Bruno, Süss-Fink, Georg

Cationic dinuclear p-cymene Ru complexes bridged by three thiophenolato ligands contg. various substituents mainly in meta and ortho positions, [(?6-p-MeC6H4Pri)2Ru2(?2-SR)3]+ (R = 3-C6H4Me: 1; R = 3-C6H4OMe: 2; R = 3-C6H4OEt: 3; R = 3-C6H4CF3: 4; R = 3-C6H4NH2: 5; R = 3-C6H4Cl: 6; R = 2-C6H4Me: 7; R = 2-C6H4OMe: 8; R = 2-C6H4Pri: 9; R = 2-C6H4CF3: 10; R = npt: 11 (npt = 2-naphthyl); R = mco: 12 (mco = 4-methylcoumarinyl); R = 3,5-C6H3Me2: 13; R = 3,5-C6H3(CF3)2: 14; R = 3,5-C6H3Cl2: 15; R = 3,4-C6H3(OMe)2: 16), were prepd. from the reaction of the neutral p-cymene diruthenium dichloride dimer, [(?6-p-MeC6H4Pri)2Ru2Cl4], with the corresponding thiophenol RSH. All cationic complexes were isolated as their chloride salts and fully characterized by spectroscopic and anal. methods. The mol. structures of 10 and 15 were solved by a single-crystal x-ray structure anal. of [10]Cl and [15]Cl, which show that the two Ru atoms adopt a pseudo-octahedral geometry without a metal-metal bond in accordance with the noble gas rule. All complexes are highly cytotoxic towards human ovarian cancer cells, the IC50 values being mostly in the nanomolar range. Complex 9 shows the highest cytotoxicity with an IC50 value of 0.03 ?M towards the A2780 cell line and the cisplatin-resistant mutant A2780cisR. The cytotoxicity of these complexes, which belong to the most active Ru anticancer compds. reported so far, can be correlated with the lipophilicity of the corresponding thiols. In comparison with the previous series, the positions of the substituents in the thiophenolato bridges are not as important as the nature of the substituents, alkyl substituents being the best ones in line with their lipophilic character. [on SciFinder(R)]

2013, Khan, Farooq-Ahmad, Therrien, Bruno, Süss-Fink, Georg, Zava, Olivier, Dyson, Paul J.

A series of p-cymene ruthenium dichloro complexes contg. isonicotinic ester ligands, [(arene)RuCl2NC5H4-4-COO-C6H4-p-O-(CH2)n-CH3] (n = 1: 1, n = 3: 2, n = 5: 3, n = 7: 4, n = 9: 5, n = 11: 6, n = 13: 7, n = 15: 8), were prepd. from p-cymene ruthenium dichloro dimer and the corresponding isonicotinic ester ligand. The single-crystal x-ray anal. of 1 shows the mol. to adopt the usual pseudo-tetrahedral piano-stool geometry, the isonicotinic ester ligand being coordinated through the nitrogen atom. The cytotoxicity of all complexes and of the free ligands was studied towards human ovarian cancer cells; high activities were obsd. only for n = 9 (presenting a chain with ten carbon atoms), both as far as the free ligands and the complexes are concerned. Based on this result, a new isonicotinic ester ligand with a C10 substituent contg. a terminal alc. function, NC5H4-4-COO-C6H4-p-O-(CH2)10-OH, was synthesized by a four-step method, and arene ruthenium complexes thereof, [(arene)RuCl2NC5H4-4-COO-C6H4-p-O-(CH2)10-OH] (arene = C6H6: 9a, arene = p-MeC6H4Pri: 9b, arene = C6Me6: 9c) were prepd. The complexes 9a and 9b show indeed remarkable anticancer activities, the IC50 values for human ovarian cancer cells being in the submicromolar range. The highest cytotoxicity was obsd. for complex 9b, with IC50 values of 0.18 ?M for A2780 and 3.04 ?M for the cisplatin-resistant mutant A2780cisR. [on SciFinder(R)]

2013, Sun, Bing, Khan, Farooq-Ahmad, Vallat, Armelle, Süss-Fink, Georg

2013, Furrer, Mona A., Garci, Amine, Denoyelle-Di-Muro, Emmanuel, Trouillas, Patrick, Giannini, Federico, Furrer, Julien, Clavel, Catherine M., Dyson, Paul J., Süss-Fink, Georg, Therrien, Bruno

Hexanuclear hexacationic thiolato-bridged arene ruthenium metalla-prisms of the general formula [[(?6-p-cymene)Ru]6(?-SR)6(?3-tpt)2][OTf]6 (R = CH2Ph, CH2C6H4-p-tBu, CH2CH2Ph; tpt = 2,4,6-tri-4-pyridyl-1,3,5-triazine), obtained from the self-assembly of dinuclear precursors [(p-cymene)2Ru2(?-SR)2Cl2] with tpt and AgCF3SO3, have been isolated and fully characterized as triflate salts. The metalla-prisms are highly cytotoxic against human ovarian cancer cells, esp. towards the cisplatin-resistant cell line A2780cisR (IC50

2013, Tauchman, Jiri, Süss-Fink, Georg, Petr Štěpnička, Zava, Oliver, Paul Dyson

2013, Raja, Mathiyazhagan Ulaganatha, Therrien, Bruno, Süss-Fink, Georg

2,2'-Dipyridyl-N-arylimines L (L1 = 2,4,6-trimethyl(di-2-pyridylmethylene)aniline, L2 = 2,6-diisopropyl(di-2-pyridylmethylene)aniline) react with arene ruthenium dichloride dimer in methanol to give cationic arene ruthenium complexes of the general type [(arene)Ru(?2-N,N-L)Cl]+ (arene = C6H6, p-MeC6H4Pri). Two coordination modes of the chelating ligands N,N-L are obsd. In the major isomer, the ketimine nitrogen atom and one of the two pyridine nitrogen atoms are coordinated to ruthenium, while in the minor isomer the two pyridine nitrogen atoms coordinate to the metal center. In the case of L1, the minor isomer of the p-cymene ruthenium chloro complex could be isolated as the tetrafluoroborate salt and characterized by single crystal X-ray anal. The mol. structure of the major isomer was detd. by X-ray crystallog. in the case of the tetraphenylborate salt of the benzene ruthenium chloro deriv. In both structures, the ruthenium atom shows the expected pseudo-tetrahedral coordination geometry. [on SciFinder(R)]