Example Of Ru Research Articles

Synthesis, Structure, Spectral, Electrochemical, and Theoretical Studies of Ru(II) Complexes of 3-Pyrrolyl BODIPY-Based Ligands.

3-Pyrrolyl BODIPY having an appended pyrrolyl group at the 3-position of BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) and its functionalized derivatives have been used as ligands to prepare one example of Ru(II) complex of pyrrolyl dipyrrin and three unique examples of bichromophoric BODIPY-Ru(II) complexes in good yields. The complexes were characterized by HR-MS, 1D and 2D NMR, X-ray analysis for two complexes, absorption, cyclic voltammetry, and DFT/TD-DFT techniques. The X-ray structure of the Ru(II) complex of pyrrolyl dipyrrin revealed that the geometry around the Ru(II) ion was pseudo-octahedral with an arene unit occupying three coordination sites in η6-fashion and two nitrogen atoms of the dipyrrin ring and one chloro group adopting the "three legs piano-stool" structure. The X-ray structure of the bichromophoric BODIPY-Ru(II) complex revealed that the BODIPY core was planar and the central B(III) was coordinated with two pyrrole nitrogens of the dipyrrin unit and two axial fluoride ions in a tetrahedral geometry, and Ru(II) was bonded to appended pyrrole "N" and "N" of benzimidazole substituent present at the α-position of appended pyrrole, one chloro group, and one arene ring in a pseudo-octahedral geometry. The spectral studies revealed that the electronic properties of the BODIPY unit in BODIPY-Ru(II) complexes were significantly altered, and electrochemical studies indicated that the BODIPY-Ru(II) complexes exhibit one oxidation corresponding to Ru(II) to Ru(III) and one reduction corresponding to the BODIPY unit. The DFT/TD-DFT studies corroborated the experimental observations.

Symmetry breaking and unconventional charge ordering in single crystal Na2.7Ru4O9

The interplay of charge, spin, and lattice degrees of freedom in matter leads to various forms of ordered states through phase transitions. An important subclass of these phenomena of complex materials is charge ordering (CO), mainly driven by mixed-valence states. We discovered by combining the results of electrical resistivity ($\rho$), specific heat, susceptibility $\chi$ (\textit{T}), and single crystal x-ray diffraction (SC-XRD) that Na$_{2.7}$Ru$_4$O$_9$ with the monoclinic tunnel type lattice (space group $C$2/$m$) exhibits an unconventional CO at room temperature while retaining metallicity. The temperature-dependent SC-XRD results show successive phase transitions with super-lattice reflections at \textbf{q}$_1$=(0, $\frac{1}{2}$, 0) and \textbf{q}$_2$=(0, $\frac{1}{3}$, $\frac{1}{3}$) below $T_{\textrm{C2}}$ (365 K) and only at \textbf{q}$_1$=(0, $\frac{1}{2}$, 0) between $T_{\textrm{C2}}$ and $T_{\textrm{C1}}$ (630 K). We interpreted these as an evidence for the formation of an unconventional CO. It reveals a strong first-order phase transition in the electrical resistivity at $T_{\textrm{C2}}$ (cooling) = 345 K and $T_{\textrm{C2}}$ (heating) = 365 K. We argue that the origin of the phase transition is due to the localized 4$d$ Ru-electrons. The results of our finding reveal an unique example of Ru$^{3+}$/Ru$^{4+}$ mixed valance heavy \textit{d}$^4$ ions.

Ruthenium(II)-Catalyzed Hydroarylation of Maleimides Using Carboxylic Acids as a Traceless Directing Group.

An efficient Ru(II)-catalyzed hydroarylation of maleimides with ready-stock aryl carboxylic acids has been developed based on weak carboxylate-directed ortho-C-H alkylation and concomitant decarboxylation processes, fabricating 3-aryl succinimides, a recurrent scaffold in drug molecules, in high yields (up to 97%). The protocol features operational simplicity, avoids the need for precious metal additives/oxidants, and offers broad substrate scope with formal meta- and para-selectivities. It represents the first example of Ru(II)-catalyzed direct arylation of maleimides with unbiased benzoic acids.

Ruthenium-Catalyzed Carbonylation of Oxalyl Amide-Protected Benzylamines with Isocyanate as the Carbonyl Source.

An efficient synthesis of isoindolin-1-ones from oxalyl amide-protected benzylamines, through ruthenium-catalyzed intramolecular C(sp2)-H carbonylation, has been developed. Variously substituted benzylamines could be well tolerated in this new protocol, affording the corresponding products in moderate to excellent yields. This approach constitutes the first example of Ru(II)-catalyzed C(sp2)-H carbonylation with isocyanate as a novel commercially available carbonyl source.

Ru(II)-Catalyzed C-H Functionalization on Maleimides with Electrophiles: A Demonstration of Umpolung Strategy.

The unconventional nucleophilic reactivity of maleimides, innate electrophiles, has been realized under Ru(II)-catalysis such that exposure to electrophiles delivered products of C-H chalcogenation and amidation in good yields (up to 94%). This protocol features mild conditions and operational simplicity with broad substrate scope, uses an inexpensive and air-stable catalyst, and also represents the first example of Ru(II) catalyzed C-H selenylation of alkenes.

Synthesis, Characterization, and Antitumor Activity of Water-Soluble (Arene)ruthenium(II) Derivatives of 1,3-Dimethyl-4-acylpyrazolon-5-ato Ligands. First Example of Ru(arene)(ligand) Antitumor Species Involving Simultaneous Ru–N7(guanine) Bonding and Ligand Intercalation to DNA

We report on the synthesis of novel water-soluble [(arene)Ru(II)(Q)Cl] and [(arene)Ru(II)(Q)(X)]BF4 compounds (arene = p-cymene, benzene, hexamethylbenzene; HQ = 1,3-dimethyl-4-R-(C═O)-5-pyrazolone, HQ(Me), R = methyl, HQ(Ph), R = phenyl, HQ(Naph), R = naphthyl; X = H2O, 9-ethylguanine), and their in vitro antitumor activity toward the cell lines MCF7 (HTB-22, human breast adenocarcinoma), HCT116 (CCL-247, human colorectal carcinoma), A2780 (human ovarian carcinoma), A549 (CCL-185, human lung carcinoma), and U87 MG (HTB-1, human glioblastoma). The X-ray crystal structures of two complexes were determined. One of them, {chlorido-(p-cymene)-[(1,3-dimethyl-4-(1-naphthoyl)-pyrazolon-5-ato]ruthenium(II)}, was also studied with density functional theory methods and was selected for docking on a DNA octamer showing intercalation between DNA bases by the naphthyl moiety and for Ru-N7(guanine) bonding.

Synthesis, electrochemistry, and photophysical properties of binuclear ruthenium(II)–terpyridine complexes comprising redox-active ferrocenyl spacer

In attempting to perturb the electronic properties of the spacer, we now describe an interesting example of Ru 2+–tpy (tpy = terpyridine) complexes with 1,1′-bis(ethynyl)polyferrocenyl moiety attached directly to the 4′-position of the tpy ligand (tpy–C C–(fc) n –C C–tpy; fc = ferrocenyl; n = 2–3). Complexes of Ru 2+–tpy have room-temperature luminescence in H 2O/CH 3CN (4/1) solution. The ground-state HOMO and LUMO energies were probed by electrochemical measurements and the excited-state photophysical properties were probed by UV–Vis absorption spectroscopy and luminescence spectroscopy. The redox behavior of [(tpy)Ru II–tpy–C C–(fc) n –C C–tpy–Ru II(tpy)] 4+ complex is dominated by the Ru 2+/Ru 3+ redox couple ( E 1/2 from 1.35 to 1.39 V), Fe 2+/Fe 3+ redox couples ( E 1/2 from 0.4 to 1.0 V) and tpy/tpy −/tpy 2− redox couples ( E 1/2 from −1.3 to −1.5 V). Electrochemical data, UV absorption and emission spectra indicate that the π-delocalization in the spacer is enhanced by the insertion of ethynyl unit. Interestingly, the insertion of ethynyl unit into the main chain causes a dramatic increase of phosphorescence yield (1.48 × 10 −4 for n = 2; 1.13 × 10 −4 for n = 3), triplet lifetime (67 ns for n = 2; 24 ns for n = 3), and emission intensity. The biferrocenyl spacer can be converted into mixed-valence biferrocenium spacer, which gives a more effective π-delocalization along main chain, by selective chemical oxidation of ferrocenyl unit. In deoxygenated H 2O/CH 3CN (4/1) solution at 25 °C, the oxidized complex of [(tpy)Ru II–tpy–C C–(fc) 2–C C–tpy–Ru II(tpy)] 5+ is nonemissive. The presence of lower energy ferrocenium-centered [ Ru a II – tpy - – fc III – fc III – tpy – Ru b II ] excited-state provides an additional channel for excited-state decay. The mixed-valence biferrocenium center acts as an efficient quencher for the MLCT excited-state.

Crystal Structure of New 10-Layer Perovskite-Related Oxyhalide, Ba 5Ru 1.6W 0.4Cl 2O 9

Crystals of Ba 5Ru 1.6W 0.4Cl 2O 9were prepared in a BaCl 2flux and investigated by X-ray diffraction methods. The structure of this new compound was solved and refined in the hexagonal symmetry space group P6 3/ mmcwith a=5.817(2) Å, c=24.839(2) Å, and Z=2 to a final Rof 0.0383. The structure of Ba 5Ru 1.6W 0.4Cl 2O 9displays a 10-layer stacking sequence of mixed [BaO 3] and [BaCl] layers containing isolated (Ru/W) 2O 9units as face-shared octahedra. Isolated face-shared Ru 2O 9units are also found in Ba 5Ru 2Cl 2O 9which otherwise has a very different structure. Ba 5Ru 1.6W 0.4Cl 2O 9appears to be the first example of Ru and W sharing the same crystallographic site.

Carbonyl Derivatives of Chloride-Dimethyl Sulfoxide-Ruthenium(III) Complexes: Synthesis, Crystal Structure, and Reactivity of [(DMSO)2H][trans-RuCl4(DMSO-O)(CO)] and mer,cis-RuCl3(DMSO-O)2(CO)

[(DMSO){sub 2}{sub 2}H][trans-RuCl{sub 4}(DMSO){sub 2}] (1) and mer,trans-RuCl{sub 3}(DMSO){sub 2}(DMSO) (2) (DMSO = S-bonded dimethyl sulfoxide; DMSO = O-bonded dimethyl sulfoxide; DMSO = O bonded dimethyl sulfoxide) react with carbon monoxide at room temperature and atmospheric pressure to give [(DMSO){sub 2}H][trans-RuCl{sub 4}(DMSO)(CO)] (3) and mer,cis-RuCl{sub 3}(DMSO){sub 2-} (CO) (4), respectively. Coordination of carbon monoxide induces the S to O linkage iosmerization of the DMSO ligand trans to it. Compounds 3 and 4 represent the first example of Ru-(III) chloride-DMSO-carbonyl complexes. In both 3 and 4 the DMSO ligand trans to CO is weakly bonded and easily replaced by a nitrogen donor ligand.

Cationic Complexes of Ruthenium(III) and Ruthenium(II) with Triphenylphosphine and Other Ligands

Abstract First example of Ru(II) and Ru(III) complexes having five PPh3 groups coordinated to the metal, viz. [Ru(PPh3)5(ClO4)] (ClO4)x, (x = 1 or 2) are reported. Some other cationic complexes, viz., [Ru(PPh3)4(CS)2]-(ClO4)x, (x = 2 or 3), and [Ru(PPh3) (CS)2(Py)2(ClO4)2 are also reported. All the cationic complexes are characterised by elemental analysis and various physical measurements.