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Upstream product

• 622-20-8 1,2-bis(phenylthio)ethane 
• 26042-63-7 silver(I) hexafluorophosphate 
• 31765-78-3 cis-bis(2,2′-bipyridine)dichlororuthenium(II) hydrate 

Relevant academic research and scientific papers

Sequential picosecond isomerizations in a photochromic ruthenium sulfoxide complex triggered by pump-repump-probe spectroscopy

The complex [Ru(bpy)2(bpSO)](PF6)2, where bpy is 2,2'-bipydine and bpSO is 1,2-bis(phenylsulfinyl)ethane, exhibits three distinct isomers which are accessible upon metal-to-ligand charge-transfer (MLCT) irradiation. This complex and its parent, [Ru(bpy)2(bpte)] (PF6)2, where bpte is 1,2-bis(phenylthio)ethane, have been synthesized and characterized by UV-visible spectroscopy, NMR, X-ray crystallography, and femtosecond transient absorption spectroscopy. A novel method of 2-color Pump-Repump-Probe spectroscopy has been employed to investigate all three isomers of the bis-sulfoxide complex. This method allows for observation of the isomerization dynamics of sequential isomerizations of each sulfoxide from MLCT irradiation of the S,S-bonded complex to ultimately form the O,O-bonded metastable complex. One-dimensional (1-D) and two-dimensional (2-D) (COSY, NOESY, and TOCSY) 1H NMR data show the thioether and ground state S,S-bonded sulfoxide complexes to be rigorously C2 symmetric and are consistent with the crystal structures. Transient absorption spectroscopy reveals that the S,S to S,O isomerization occurs with an observed time constant of 56.8 (±7.4) ps. The S,O to O,O isomerization time constant was found to be 59 (±4) ps by pump-repump-probe spectroscopy. The composite S,S- to O,O-isomer quantum yield is 0.42.

Effect of electronic structure on the photoinduced ligand exchange of Ru(II) polypyridine complexes

The series of complexes [Ru(bpy)2(L)]2+, where bpy = 2,2′-bipyridine and L = 3,6-dithiaoctane (bete, 1), 1,2-bis(phenylthio) ethane (bpte, 2), ethylenediamine (en, 3), and 1,2-dianilinoethane (dae, 4), were synthesized, and their photochemistry was investigated. Photolysis experiments show that the bisthioether ligands in 1 and 2 are more easily photosubstituted by chloride ions, bpy, and H2O than the corresponding diammine complexes in 3 and 4 to generate the bis-substituted products. Electronic structure calculations show that bond elongation in the lowest energy triplet metal-to-ligand charge transfer (3MLCT) state compared to the ground state is greater for complexes containing bisthioether ligands than those with coordinated bidentate nitrogen atoms. This elongation in the excited state is attributed to Ru-S π-bonding character of the highest occupied molecular orbitals, which is not present in the diamine complexes. In the Ru→bpy 3MLCT state, the lower electron density on the metal-centered highest occupied molecular orbital (HOMO) weakens the Ru-S bond and results in the greater photoreactivity of 1 and 2 relative to that of 3 and 4. The more efficient photoinduced ligand exchange of the complexes possessing thioether ligands results in binding of 1 and 2 to DNA upon irradiation.

Thioether, thiolato, and 1,1-dithioato complexes of bis(2,2′-bipyridine)ruthenium(II) and bis(2,2′-bipyridine)osmium(II)

A series of bis(2,2′-bipyridine)ruthenium(II) complexes containing sulfur-donating ligands has been prepared. In these complexes the two coordination sites not occupied by bipyridine are occupied by the following ligands or ligand combinations: CH3SC-H2CH2SCH3, CH3CH2SCH2CH2SCH2CH 3, C6H5SCH2CH2SC6H 5, 3,4-CH3SC6H3(CH3)SCH3, cis-[S(CH3)2]2, trans-[S(CH3)2]2, CH3SCH2CH2NH2, C6H5CH2SCH2CH2NH 2, C6H5SCH2CH2NH2, CH3S(O)CH2CH2NH2, cis-[X,S(CH2CH3)2] (X = Cl, Br), cis-[Cl,S(CH3)C6H5], cis-[P(C6H5)3, S(CH2CH3)2], cis-[-SC6H5]2, cis-[-SC6F5]2, -S2CN(CH3)2, -S2CN(CH2CH3)2, -S2CN-(CH2)4, -S2COCH2CH3. Related bis(2,2′-bipyridine)osmium(II) complexes have been prepared with the following thioether ligand combinations: cis-[S(CH3)C6H5]2, cis-[4-S(CH3)C6H4C(CH3) 3]2, 3,4-CH3SC6H3(CH3)SCH3. All complexes have been characterized by elemental analyses, cyclic voltammetry, and visible-UV spectrophotometry. Selected complexes have also been characterized by 1H and 13C NMR spectroscopy, and emission spectra for the three Os(II) complexes have been obtained in acetonitrile solution. The redox and spectral properties of the sulfur-containing (bpy)2MII complexes can be rationalized in terms of the relative π-acid character of halogen-, nitrogen-, phosphorus-, and sulfur-containing ligands, within the tenet that π back-bonding is the salient feature of the chemistry of Ru(II) and Os(II) complexes. In general, the sulfur-containing (bpy)2MII complexes have properties intermediate between those of amine-containing and phosphine-containing analogues. Among the sulfur-Ru(II) complexes, the potential of the Ru(II)/Ru(III) couple increases with the increasing formal charge of the complex (thiolate 2(thioether)2OsII]2+ complexes are more readily oxidized (by 0.3-0.4 V) than the corresponding Ru(II) complexes, consistent with established periodic trends.