Terminal water ligand exchange and substitution by isonicotinamide on the oxo-centred triruthenium(III) complex [Ru3(μ3-O)(μ-CH3CO2)6(OH2)3]+. Crystal structure of [Ru3(μ3-O)(μ-CH3CO2)6(OH2)3]ClO4·HClO4·H2O

Powell, Glenmore; Richens, David T.; Powell, A. K.

doi:10.1016/s0020-1693(00)83825-6

Cited by 31 publications

(15 citation statements)

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“…[3][4][5][6][7][8][9][10][11] A well-defined family of trinuclear ruthenium clusters of the type [Ru 3 ( 3 -O)(-OOCCH 3 ) 6 L 3 ] n+ , 12,13 in which L represents a monodentate ligand such as pyridine (py), is of considerable interest due to their reversible multistep redox chemistry, [14][15][16][17][18] intramolecular charge transfer [19][20][21][22] and terminal ligand-substitution reactions. [23][24][25][26] It is known that mixed-valent triruthenium(II,III,III) complexes with a terminal CO ligand of the type [Ru 3 ( 3 -O)(-OOCCH 3 ) 6 (CO)L 2 ] dissociate CO upon one-electron chemical oxidation of the triruthenium core to afford solvent-coordinated complexes [Ru 3 ( 3 -O)(-OOCCH 3 ) 6 (sol)L 2 ] + (sol = CH 3 OH or H 2 O). 14,16 The solvent ligand in the product can be readily replaced by N-heterocyclic ligands or others (L′) to give a wide variety of substituted triruthenium derivatives [Ru 3 ( 3 -O)(-OOCCH 3 ) 6 L′L 2 ] + .…”

Section: Introductionmentioning

confidence: 99%

Photodissociation of CO from [Ru3(µ3-O)(µ-OOCCH3)6(CO)L2] in acetonitrile, where L = pyridine, 4-cyanopyridine and methanol

et al. 2004

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Photodissociation of CO from oxo-centered trinuclear ruthenium clusters [Ru3(mu3-O)(mu-OOCCH3)6(CO)L2] (L = pyridine (py): 1; 4-cyanopyridine (cpy): 2; methanol: 3) dissolved in organic solvents has been examined. Upon photolysis (> or = 290 nm, a 450-W Xe lamp), an absorption peak at 585 nm observed for 1 in CH3CN decreases its intensity and a new absorption band appears and grows at 896 nm. This spectral change, presenting isosbestic points, corresponds to photosubstitution of CO in 1 to form [Ru3(mu3-O)(mu-OOCCH3)6(CH3CN)(py)2] 4. Photoexcitation of carbonyl complexes 2 and 3 in CH3CN also affords the corresponding CH3CN-coordinated complexes [Ru3(mu3-O)(mu-OOCCH3)6(CH3CN)(cpy)2] 6 and [Ru3(mu3-O)(mu-OOCCH3)6(CH3CN)3] 7, respectively. The photosubstitution reactions (excitation wavelength, > or = 290 nm) are well described by the first-order kinetics: k = 7.3 x 10(-4) s(-1) for 1, 4.9 x 10(-4) s(-1) for 2 and 5.1 x 10(-4) s(-1) for 3 (298 K). In the presence of a 100-fold excess of py, photolysis of 1 yields a tris(py) complex [Ru3(mu3-O)(mu-OOCCH3)6(py)3] 5 via photochemical loss of CO followed by coordination of py. The overall reaction (photochemical and thermal) is also confirmed by 1H NMR spectroscopy. The dissociative character of the photosubstitution is supported by negligible effects of the concentration of the entering pyridine molecule, the nature of solvents and the type of terminal monodentate ligands (other than CO) attached to the cluster. Quantum yield measurements with varied excitation wavelengths have shown that absorption bands located in the UV region (< 400 nm) play a principal role in photosubstitution, whereas an absorption band in the visible region (centered at approximately 580 nm), ascribed to an "intracluster" charge transfer, is not at all responsible for photosubstitution.

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Section: Introductionmentioning

confidence: 99%

Photodissociation of CO from [Ru3(µ3-O)(µ-OOCCH3)6(CO)L2] in acetonitrile, where L = pyridine, 4-cyanopyridine and methanol

et al. 2004

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“…Oxo-centered triruthenium basic carboxylates of the general formula [Ru 3 (μ 3 -O)(μ-RCO 2 ) 6 L 3 ] n + (RCO 2 - = a carboxylate anion, L = a neutral monodentate ligand such as H 2 O and pyridine, n = 0, 1) − serve as a remarkable class of metal clusters due to their reversible multistep and multielectron redox chemistry. − It has been well established that replacement of one Ru, three terminal ligands (L), and six carboxylate bridges (RCO 2 - ) results in a systematic tuning upon redox potentials as well as electronic, magnetic, and ligand-substitution properties. − Thus, the triruthenium complexes are thought to be a desirable unit for constructing multielectron redox systems that are inherently of interest in designing tunable multielectron redox catalysts. Synthetic examples of ligand-bridged Ru 3 clusters include the pyrazine-bridged dimer, trimer, and linear and branched tetramers of the Ru 3 unit and Ru 3 complexes having bridged-metal complex fragments at terminal positions .…”

Section: Introductionmentioning

confidence: 99%

Oxo-Centered Mixed-Ligand Triruthenium Complexes Having Redox-Active N-Methyl-4,4‘-bipyridinium Ions (mbpy⁺). Reversible Multistep Electrochemical Properties of [Ru^III₂Ru^II(μ₃-O)(μ-CH₃CO₂)₆(mbpy⁺)₂(CO)]²⁺ and [Ru^III₃(μ₃-O)(μ-CH₃CO₂)₆(mbpy⁺)₂(L)]³⁺ (L = H₂O and N-Het

et al. 1996

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A new series of oxo-centered acetate-bridged triruthenium comlexes having two redox-active N-methyl-4,4'-bipyridinium ions (mbpy(+)) have been prepared, and their reversible multistep and multielectron electrochemical properties are reported: [Ru(III)(2)Ru(II)(&mgr;(3)-O)(&mgr;-CH(3)CO(2))(6)(mbpy(+))(2)(CO)](2+) and [Ru(III)(3)(&mgr;(3)-O)(&mgr;-CH(3)CO(2))(6)(mbpy(+))(2)(L)](3+) (L = H(2)O, pyrazine (pz), pyridine (py), imidazole (Him), and 4-(dimethylamino)pyridine (dmap)). Among these series, the CO complex, [Ru(III)(2)Ru(II)(&mgr;(3)-O)(&mgr;-CH(3)CO(2))(6)(mbpy(+))(2)(CO)](ClO(4))(2).2DMF (1b.2DMF) was structurally characterized by X-ray crystallography. 1b.2DMF crystallizes in the monoclinic space group P2(1)/m (No. 11) with a = 8.740(6) Å, b = 32.269(6) Å, c = 10.276(4) Å, beta = 103.37(5) degrees, V = 2820(2) Å(3), Z = 2, d(calcd) = 1.636 g cm(-)(3), and R = 0.071 (R(w) = 0.074) for 5277 independent reflections (|F(o)| > 3sigma(|F(o)|). The (CO)Ru.Ru distance (3.410(2) Å) is appreciably longer than the other Ru.Ru distance (3.276(2) Å), indicating that the trinuclear core is in the valence-trapped Ru(III)(2)Ru(II)(CO) oxidation state. The cyclic voltammogram of [Ru(III)(2)Ru(II)(&mgr;(3)-O)(&mgr;-CH(3)CO(2))(6)(mbpy(+))(2)(CO)](PF(6))(2) (1a) shows a total of seven reversible one-electron redox steps at E(1/2) = +0.90, +0.26, -1.07, -1.17, -1.56, -1.97, and -2.32 V and one irreversible step at E(pc) = -2.99 V vs Fc/Fc(+) in a 0.1 M [(n-C(4)H(9))(4)N]PF(6)-CH(3)CN solution (M = mol dm(-)(3)). All of the waves are clearly assignable to the triruthenium "Ru(3)(&mgr;(3)-O)" core-based or mbpy(+) ligand-based processes. The splitting of each ligand-based redox processes (mbpy(+)/mbpy(*) and mbpy(*)/mbpy(-)) into two one-electron steps indicates that electronic interactions between two terminal ligands occur through the triruthenium cluster core. Other mixed-ligand Ru(III)(3) analogs also show multistep redox behavior involving a total of eight or nine electrons. While the extent of interactions between ligands is much smaller than that found in the CO complex, it is systematically changed by the nature of L; with more basic L, interactions between two mbpy(+) ligands become larger.

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“…[41,[55][56][57] The reaction rate constant of CO liberation in the triruthenium cluster monolayer was previously carried out by evaluating the change of the peak charge in the CV with respect to the electrolysis time. [13] However, in order to record a series of CV, the reaction process has to be frequently stopped.…”

mentioning

confidence: 99%

Oxidation States and CO Ligand Exchange Kinetics in a Self‐Assembled Monolayer of a Triruthenium Cluster Studied by In Situ Infrared Spectroscopy

Zhou

Abe

et al. 2005

Chemistry A European J

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Oxidation states and CO ligand exchange kinetics in a self-assembled monolayer (SAM) of an oxo-centered triruthenium cluster [Ru(3)(mu3-O)(mu-CH3COO)6(CO)(L1)(L2)] (L1 = [(NC5H4)CH2NHC(O)(CH2)10S-]2, L2 = 4-methylpyridine) have been extensively investigated on the surface of a gold electrode in aqueous and nonaqueous solutions. The SAM exhibits three consecutive one-electron transfers and four oxidation states, which have been characterized by electrochemistry, in situ infrared spectroscopy, and in situ sum frequency generation (SFG) vibrational spectroscopy measurements. The original electron-localized state of the Ru cluster center was changed to electron delocalization states by oxidation or reduction of the central Ru ions. These changes are revealed by the IR absorptions of the CO ligand and the bridging acetate ligands of the triruthenium cluster in the SAM. The IR absorptions of the two kinds of ligands are strongly dependent on the oxidation state of the Ru cluster center. One-electron oxidation of the central Ru ion in the SAM triggers a CO ligand liberation process. Solvent molecules may then occupy the CO site to result in a CO-free SAM. One-electron reduction of this CO-free SAM in a CO-saturated solution leads to re-coordination of the CO ligand into the SAM. Both processes can be precisely controlled by tuning the electrode potential. The kinetics of the CO exchange cycle in the SAM, including liberation and coordination, has been investigated by in situ IR and SFG measurements for the first time. The CO exchange cycle is significantly dependent on the temperature. The reaction rate greatly decreases with decreasing solution temperature, which is an important factor in the CO ligand exchange process. The activation energies of both CO liberation and coordination have been evaluated from the reaction rate constants obtained at various temperatures.

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Terminal water ligand exchange and substitution by isonicotinamide on the oxo-centred triruthenium(III) complex [Ru3(μ3-O)(μ-CH3CO2)6(OH2)3]+. Crystal structure of [Ru3(μ3-O)(μ-CH3CO2)6(OH2)3]ClO4·HClO4·H2O

Cited by 31 publications

References 48 publications

Photodissociation of CO from [Ru3(µ3-O)(µ-OOCCH3)6(CO)L2] in acetonitrile, where L = pyridine, 4-cyanopyridine and methanol

Photodissociation of CO from [Ru3(µ3-O)(µ-OOCCH3)6(CO)L2] in acetonitrile, where L = pyridine, 4-cyanopyridine and methanol

Oxidation States and CO Ligand Exchange Kinetics in a Self‐Assembled Monolayer of a Triruthenium Cluster Studied by In Situ Infrared Spectroscopy

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Terminal water ligand exchange and substitution by isonicotinamide on the oxo-centred triruthenium(III) complex [Ru3(μ3-O)(μ-CH3CO2)6(OH2)3]+. Crystal structure of [Ru3(μ3-O)(μ-CH3CO2)6(OH2)3]ClO4·HClO4·H2O

Cited by 31 publications

References 48 publications

Photodissociation of CO from [Ru3(µ3-O)(µ-OOCCH3)6(CO)L2] in acetonitrile, where L = pyridine, 4-cyanopyridine and methanol

Photodissociation of CO from [Ru3(µ3-O)(µ-OOCCH3)6(CO)L2] in acetonitrile, where L = pyridine, 4-cyanopyridine and methanol

Oxo-Centered Mixed-Ligand Triruthenium Complexes Having Redox-Active N-Methyl-4,4‘-bipyridinium Ions (mbpy+). Reversible Multistep Electrochemical Properties of [RuIII2RuII(μ3-O)(μ-CH3CO2)6(mbpy+)2(CO)]2+ and [RuIII3(μ3-O)(μ-CH3CO2)6(mbpy+)2(L)]3+ (L = H2O and N-Het

Oxidation States and CO Ligand Exchange Kinetics in a Self‐Assembled Monolayer of a Triruthenium Cluster Studied by In Situ Infrared Spectroscopy

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