trans-Diaquabis(2,2′-bipyridine-κ2N,N′)ruthenium(II) bis(trifluoromethanesulfonate)

Jude, Hershel; White, Peter S.; Dattelbaum, Dana M.; Rocha, Reginaldo C.

doi:10.1107/s1600536808028195

Cited by 5 publications

(1 citation statement)

References 7 publications

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“…The RuÀN pyridine and RuÀN pyrazine distances vary in the 2.03-2.08 and 1.93-1.96 ranges, respectively, which are consistent with the typical values observed for related polypyridyl complexes of Ru II . [2,4,[6][7][8][10][11][12] As expected, the N2 atom trans to the strongly donor Cl À ligand exhibits the shortest Ru À N pyridine bond length, owing to the enhanced Ru II !N bpy p-backbonding interaction. The shorter Ru À N pyrazine and Ru2ÀN10 distances relative to the other RuÀN distances reflect both the strongly p-acceptor electronic character of the bridging pyrazine ring and the structural constraints of the meridionally coordinated tridendate ligands.…”

Section: Resultsmentioning

confidence: 62%

Catalytic Photooxidation of Alcohols by an Unsymmetrical Tetra(pyridyl)pyrazine‐Bridged Dinuclear Ru Complex

Chen

Rein

Scott

et al. 2011

Chemistry A European J

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The dinuclear complexes [(tpy)Ru(tppz)Ru(bpy)(L)](n+) (where L is Cl(-) or H(2)O, tpy and bpy are the terminal ligands 2,2':6',2''-terpyridine and 2,2'-bipyridine, and tppz is the bridging backbone 2,3,5,6-tetrakis(2-pyridyl)pyrazine) were prepared and structurally and electronically characterized. The mononuclear complexes [(tpy)Ru(tppz)](2+) and [(tppz)Ru(bpy)(L)](m+) were also prepared and studied for comparison. The proton-coupled, multi-electron photooxidation reactivity of the aquo dinuclear species was shown through the photocatalytic dehydrogenation of a series of primary and secondary alcohols. Under simulated solar irradiation and in the presence of a sacrificial electron acceptor, the photoactivated chromophore-catalyst complex (in aqueous solutions at room temperature and ambient pressure conditions) can perform the visible-light-driven conversion of aliphatic and benzylic alcohols into the corresponding carbonyl products (i.e., aldehydes or ketones) with 100% product selectivity and several tens of turnover cycles, as probed by NMR spectroscopy and gas chromatography. Moreover, for aliphatic substrates, the activity of the photocatalyst was found to be highly selective toward secondary alcohols, with no significant product formed from primary alcohols. Comparison of the activity of this tppz-bridged complex with that of the analogue containing a back-to-back terpyridine bridge (tpy-tpy, i.e., 6',6''-bis(2-pyridyl)-2,2':4',4'':2'',2'''-quaterpyridine) demonstrated that the latter is a superior photocatalyst toward the oxidation of alcohols. The much stronger electronic coupling with significant delocalization across the strongly electron-accepting tppz bridge facilitates charge trapping between the chromophore and catalyst centers and therefore is presumably responsible for the decreased catalytic performance.

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Section: Resultsmentioning

confidence: 62%

Catalytic Photooxidation of Alcohols by an Unsymmetrical Tetra(pyridyl)pyrazine‐Bridged Dinuclear Ru Complex

Chen

Rein

Scott

et al. 2011

Chemistry A European J

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Cis–Trans Interconversion in Ruthenium(II) Bipyridine Complexes

2019

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Most studies of ruthenium polypyridine complexes are devoted to their cis isomers. The fact that cis isomers are thermally more stable and thus easier to synthesize has prevented researchers from investigating the properties and applications of trans complexes. We present a study of thermal and photochemical cis−trans interconversion of the key complex [Ru-(bpy) 2 (PMe 3 )(H 2 O)] 2+ (bpy = 2,2′-bipyridine, PMe 3 = trimethylphosphine), which results in specific synthetic applications of the trans species, potentially useful as a platform for designing highly efficient visible light activated caged compounds. We show, as a proof of concept, some examples of trans complexes bearing N-donor and P-donor ligands and their comparison with the cis isomers.

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Electronic Structure of the Water Oxidation Catalyst cis,cis-[(bpy)₂(H₂O)Ru^IIIORu^III(OH₂)(bpy)₂]⁴⁺, The Blue Dimer

Jurss

Concepcion

Butler³

et al. 2012

Inorg. Chem.

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The first designed molecular catalyst for water oxidation is the "blue dimer", cis,cis-[(bpy)(2)(H(2)O)Ru(III)ORu(III)(OH(2))(bpy)(2)](4+). Although there is experimental evidence for extensive electronic coupling across the μ-oxo bridge, results of earlier DFT and CASSCF calculations provide a model with magnetic interactions of weak to moderately coupled Ru(III) ions across the μ-oxo bridge. We present the results of a comprehensive experimental investigation, combined with DFT calculations. The experiments demonstrate both that there is strong electronic coupling in the blue dimer and that its effects are profound. Experimental evidence has been obtained from molecular structures and key bond distances by XRD, electrochemically measured comproportionation constants for mixed-valence equilibria, temperature-dependent magnetism, chemical properties (solvent exchange, redox potentials, and pK(a) values), XPS binding energies, analysis of excitation-dependent resonance Raman profiles, and DFT analysis of electronic absorption spectra. The spectrum can be assigned based on a singlet ground state with specific hydrogen-bonding interactions with solvent molecules included. The results are in good agreement with available experimental data. The DFT analysis provides assignments for characteristic absorption bands in the near-IR and visible regions. Bridge-based dπ → dπ* and interconfiguration transitions at Ru(III) appear in the near-IR and MLCT and LMCT transitions in the visible. Reasonable values are also provided by DFT analysis for experimentally observed bond distances and redox potentials. The observed temperature-dependent magnetism of the blue dimer is consistent with a delocalized, diamagnetic singlet state (dπ(1)*)(2) with a low-lying, paramagnetic triplet state (dπ(1)*)(1)(dπ(2)*)(1). Systematic structural-magnetic-IR correlations are observed between ν(sym)(RuORu) and ν(asym)(RuORu) vibrational energies and magnetic properties in a series of ruthenium-based, μ-oxo-bridged complexes. Consistent with the DFT electronic structure model, bending along the Ru-O-Ru axis arises from a Jahn-Teller distortion with ∠Ru-O-Ru dictated by the distortion and electron-electron repulsion.

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trans-Diaquabis(2,2′-bipyridine-κ²N,N′)ruthenium(II) bis(trifluoromethanesulfonate)

Cited by 5 publications

References 7 publications

Catalytic Photooxidation of Alcohols by an Unsymmetrical Tetra(pyridyl)pyrazine‐Bridged Dinuclear Ru Complex

Catalytic Photooxidation of Alcohols by an Unsymmetrical Tetra(pyridyl)pyrazine‐Bridged Dinuclear Ru Complex

Cis–Trans Interconversion in Ruthenium(II) Bipyridine Complexes

Electronic Structure of the Water Oxidation Catalyst cis,cis-[(bpy)₂(H₂O)Ru^IIIORu^III(OH₂)(bpy)₂]⁴⁺, The Blue Dimer

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trans-Diaquabis(2,2′-bipyridine-κ2N,N′)ruthenium(II) bis(trifluoromethanesulfonate)

Cited by 5 publications

References 7 publications

Catalytic Photooxidation of Alcohols by an Unsymmetrical Tetra(pyridyl)pyrazine‐Bridged Dinuclear Ru Complex

Catalytic Photooxidation of Alcohols by an Unsymmetrical Tetra(pyridyl)pyrazine‐Bridged Dinuclear Ru Complex

Cis–Trans Interconversion in Ruthenium(II) Bipyridine Complexes

Electronic Structure of the Water Oxidation Catalyst cis,cis-[(bpy)2(H2O)RuIIIORuIII(OH2)(bpy)2]4+, The Blue Dimer

Contact Info

Product

Resources

About

trans-Diaquabis(2,2′-bipyridine-κ²N,N′)ruthenium(II) bis(trifluoromethanesulfonate)

Electronic Structure of the Water Oxidation Catalyst cis,cis-[(bpy)₂(H₂O)Ru^IIIORu^III(OH₂)(bpy)₂]⁴⁺, The Blue Dimer