21487-48-9Relevant articles and documents
Solution equilibrium, structural and cytotoxicity studies on Ru(η6-p-cymene) and copper complexes of pyrazolyl thiosemicarbazones
D?m?t?r, Orsolya,Kiss, Márton A.,Gál, G. Tamás,May, Nóra V.,Spengler, Gabriella,Nové, Márta,Ga?parovi?, Ana ?ipak,Frank, éva,Enyedy, éva A.
, (2019/11/11)
Solution chemical properties of two bidentate pyrazolyl thiosemicarbazones 2-((3-methyl-1-phenyl-1H-pyrazol-4-yl)methylene)hydrazinecarbothioamide (Me-pyrTSC), 2-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)hydrazinecarbothioamide (Ph-pyrTSC), stability of their Cu(II) and Ru(η6-p-cymene) complexes were characterized in aqueous solution (with 30% DMSO) by the combined use of UV–visible spectrophotometry, 1H NMR spectroscopy and electrospray ionization mass spectrometry in addition to their solid phase isolation. The solid phase structures of Me-pyrTSC?H2O, [Ru(η6-p-cymene)(Me-pyrTSC)Cl]Cl and [Cu(Ph-pyrTSCH?1)2] were determined by single crystal X-ray diffraction. High stability mononuclear Ru(η6-p-cymene) complexes with (N,S) coordination mode are formed in the acidic pH range, and increasing the pH the predominating dinuclear [(Ru(η6-p-cymene))2(L)2]2+ complex with μ2-bridging sulphur donor atoms is formed (where L? is the deprotonated thiosemicarbazone). [CuL]+ and [CuL2] complexes show much higher stability compared to that of complexes of the reference compound benzaldehyde thiosemicarbazone. [CuL2] complexes predominate at neutral pH. Me-pyrTSC and Ph-pyrTSC exhibited moderate cytotoxicity against human colonic adenocarcinoma cell lines (IC50 = 33–76 μM), while their complexation with Ru(η6-p-cymene) (IC50 = 11–24 μM) and especially Cu(II) (IC50 = 3–6 μM) resulted in higher cytotoxicity. Cu(II) complexes of the tested thiosemicarbazones were also cytotoxic in three breast cancer and in a hepatocellular carcinoma cell line. No reactive oxygen species production was detected and the relatively high catalase activity of SUM159 breast cancer cells was decreased upon addition of the ligands and the complexes. In the latter cell line the tested compounds interfered with the glutathione synthesis as they decreased the concentration of this cellular reductant.
Electronic Structure and Multicatalytic Features of Redox-Active Bis(arylimino)acenaphthene (BIAN)-Derived Ruthenium Complexes
Singha Hazari, Arijit,Ray, Ritwika,Hoque, Md Asmaul,Lahiri, Goutam Kumar
, p. 8160 - 8173 (2016/08/24)
The article examines the newly designed and structurally characterized redox-active BIAN-derived [Ru(trpy)(R-BIAN)Cl]ClO4 ([1a]ClO4-[1c]ClO4), [Ru(trpy)(R-BIAN)(H2O)](ClO4)2 ([3a](ClO4)2-[3c](ClO4)2), and BIAO-derived [Ru(trpy)(BIAO)Cl]ClO4 ([2a]ClO4) (trpy = 2,2′:6′,2′′-terpyridine, R-BIAN = bis(arylimino)acenaphthene (R = H (1a+, 3a2+), 4-OMe (1b+, 3b2+), 4-NO2 (1c+, 3c2+), BIAO = [N-(phenyl)imino]acenapthenone). The experimental (X-ray, 1H NMR, spectroelectrochemistry, EPR) and DFT/TD-DFT calculations of 1an-1cn or 2an collectively establish {RuII-BIAN0} or {RuII-BIAO0} configuration in the native state, metal-based oxidation to {RuIII-BIAN0} or {RuIII-BIAO0}, and successive electron uptake processes by the α-diimine fragment, followed by trpy and naphthalene π-system of BIAN or BIAO, respectively. The impact of the electron-withdrawing NO2 function in the BIAN moiety in 1c+ has been reflected in the five nearby reduction steps within the accessible potential limit of -2 V versus SCE, leading to a fully reduced BIAN4- state in [1c]4-. The aqua derivatives ({RuII-OH2}, 3a2+-3c2+) undergo simultaneous 2e-/2H+ transfer to the corresponding {RuIV-O} state and the catalytic current associated with the RuIV/RuV response probably implies its involvement in the electrocatalytic water oxidation. The aqua derivatives (3a2+-3c2+) are efficient and selective precatalysts in transforming a wide variety of alkenes to corresponding epoxides in the presence of PhI(OAc)2 as an oxidant in CH2Cl2 at 298 K as well as oxidation of primary, secondary, and heterocyclic alcohols with a large substrate scope with H2O2 as the stoichiometric oxidant in CH3CN at 343 K. The involvement of the {RuIV-O} intermediate as the active catalyst in both the oxidation processes has been ascertained via a sequence of experimental evidence.
An expedient osmium(vi)/K3Fe(CN)6-mediated selective oxidation of benzylic, allylic and propargylic alcohols
Fernandes, Rodney A.,Bethi, Venkati
, p. 40561 - 40568 (2015/02/18)
A chemoselective osmium(vi) catalyzed oxidation of benzylic, allylic and propargylic alcohols using K3Fe(CN)6as a secondary oxidant is described. This protocol is operationally simple and exhibits excellent chemoselectivity favouring the oxidation of benzylic alcohols over the aliphatic alcohols. A larger scale reaction was also found to be compatible. This journal is
