299208-26-7Relevant academic research and scientific papers
Electrochemical and Spectroscopic Studies on σ-Phenyl Ruthenium Complexes Ru(CO)Cl(C6H4R-4)(PiPr3)2
Muck, Christina S.,Linseis, Michael,Welte, Hannah,Weickert, Sabrina,Drescher, Malte,Winter, Rainer F.
, p. 2111 - 2122 (2018)
A series of mononuclear σ-phenyl ruthenium complexes Ru(CO)Cl(C6H4-R)(PiPr3)2 (R = OMe, CH3, H, F, CF3) were synthesized and analyzed with respect to their electrochemical and spectroscopic properties. To these ends, cyclic voltammetry, IR, and UV/Vis/NIR spectroelectrochemistry as well as EPR spectroscopy on their one-electron oxidized radical cations were employed. Experimental work is complimented by quantum chemical calculations. Our studies reveal that the σ-phenyl ligand strongly contributes to the HOMO and actively participates in the redox processes. Despite comparatively smaller ligand contributions, the redox potentials, the position of the CO stretch as well as the oxidation induced CO band shifts are more sensitive toward the σ-Hammett parameter of the 4-substituent than for related styryl complexes with the same Ru(CO)Cl(PiPr3)2 metal coligand platform. The comparatively high spin density/positive charge at the 4-position of the phenyl ligand leads to oxidatively induced dehydrodimerization of the radical cation of the parent phenyl complex Ru(CO)Cl(C6H5)(PiPr3)2 (1) to the biphenylene-bridged dinuclear complex [{Ru(CO)Cl(PiPr3)2}2(μ-C6H4-C6H4-4,4′)]n+ (6n+). The latter was identified in spectroelectrochemical experiments and authenticated by independent preparation of neutral 6 and monitoring of its spectroelectrochemical behavior.
Displacement of phenyl and styryl ligands by benzophenone imine and 2-vinylpyridine on ruthenium and osmium
Bull, Maria L.,Esteruelas, Miguel A.,Goni, Eva,Olivan, Montserrat,Onate, Enrique
, p. 3076 - 3083 (2008/10/09)
The phenyl complexes MPhCl(CO)(PiPr3)2 (M = Ru (3), Os (4)) have been prepared by reaction of MHCl(CO)(P iPr3)2 (M = Ru (1), Os (2)) with HgPh 2. In solution the phenyl ligand of these compounds rotates around the M-Ph bond. The activation parameters for the process are ΔH? = 13.0 ± 0.6 kcal·mol-1 and ΔS? = 1.5 ± 1.3 cal·mol-1·K-1 for 3 and ΔH? = 11.7 ± 0.5 kcal·mol-1 and ΔS? = -5.4 ± 1.2 cal·mol-1·K -1 for 4. The addition of benzophenone imine to dichloromethane solutions of 3 and 4 and the related styryl complexes M{(E)-CH=CHPh}Cl(CO) (PiPr3)2 (M = Ru (7), Os (8)) leads to equilibrium mixtures between the starting compounds and the six-coordinate derivatives MPhCl(NH=CPh2)(CO)(PiPr3) 2 (M = Ru (5): ΔHo = -8.6 ± 0.4 kcal·mol-1, ΔSo = -42.5 ± 1.6 cal·mol-1·K-1; M = Os (6): ΔH o = -9.1 ± 0.8 kcal·mol-1, ΔS o = -31.0 ± 2.6 cal·mol-1·K -1) and M{(E)-CH=CHPh}Cl(NH= CPh2)(CO)(P iPr3)2 (M = Ru (9): ΔHo = -9.5 ± 0.3 kcal·mol-1, ΔSo = -39.4 ± 1.1 cal·mol-1·K-1; M = Os (10): ΔHo = -8.8 ± 0.8 kcal·mol-1, ΔSo = -27.3 ± 2.6 cal·mol -1·K-1). In toluene under reflux complexes 3, 4, 7, and 8 react with benzophenone imine and 2-vinylpyridine to afford the metalated derivatives M{C6H4C(Ph)=NH}Cl(CO)PiPr 3)2 (M = Ru (11), Os (12)) and M(NC5H 4-o-CH=CH)Cl-(CO)(PiPr3)2 (M = Ru (13), Os (14)), releasing benzene and styrene. Complexes 9, 12, and 13 have been characterized by X-ray diffraction analysis. The structure of 9 shows a Cl...H-N hydrogen bond (2.47 A) between the NH hydrogen atom of the imine and the chloride ligand.
Cleavage of H-C(sp2) and C(sp2)-X Bonds (X = Alkyl, Aryl, OR, NR2): Facile decarbonylation, isonitrile abstraction, or dehydrogenation of aldehydes, esters, amides, amines, and imines by [RuHCl(PiPr3)2]2
Coalter III, Joseph N.,Huffman, John C.,Caulton, Kenneth G.
, p. 3569 - 3578 (2008/10/08)
The RuHClL2 fragment (L = PiTr3) reacts at 25 °C with a dozen different G=CHE compounds (G = O, E = R, OR, NR2; G = NR, E = R) to give π-acid abstraction products, RuHCl(CG)L2, and E-H. For E-H = C2H5OH, alcohol is decarbonylated in a second step to give an additional CO ligand and CH4. For E-H = HNR(CR′2H), amine can be dehydrogenated by RuHClL2 to give RuH(H2)ClL2 and CR′2=NR. X-ray crystallographic studies are presented for the DMF decarbonylation intermediate Ru(H)2Cl(η2-C(O)NMe2)L2, where the strong reducing potential of RuHClL2 is manifested in the formally Ru(IV) species obtained from oxidative addition of H-C(O)NMe2. The structure of Ru(H2)Cl(η2-C6H4CH=NMe)L 2, the product from aryl C-H activation of benzylidenemethylamine, PhHC=NMe, is also presented. This ability to abstract CO, isonitrile, or H2 is traced to the considerable π-basicity of RuHCl(PiPr3)2.
