Polypyridine ruthenium complexes

The excited state reactions of tris(polypyridine)ruthenium complexes have been reviewed. The rate constants for the oxidative quenching of the luminescence of [ Ru(bpy)3] " and [ Ru(bpy)2(4,4 -Cl2bpy)] by the heteropolytungstate [Mn(0H)PWii039] and [Co(H20)SiW,039] ions have been measured as a... 

Kanoufi F, Bard AJ (1999) Electrogenerated Chemiluminescence. 65. An investigation of the oxidation of oxalate by tris(polypyridine) ruthenium complexes and the effect of the electrochemical steps on the emission intensity. J Phy Chem B 103(47) 10469-10480. doi 10.1021/jp992368s... 

Lachaud F, Jeandon C, Monari A, Assfeld X, Beley M, Ruppert R, Gros PC (2012) New dyads using (metallo)porphyrins as ancillary ligands in polypyridine ruthenium complexes. Synthesis and electronic properties. Dalton Trans 41(41) 12865-12871... 

Polypyridine ruthenium (II) chelate complex [Ru (Bpy) ] is known to participate in a photoredox reaction on excitation with visible light, coupled with the... 

A dendrimer with metal complexes both in the core and in the branches was described by Balzani et al. The luminescent, heteroleptic (having different ligands), dendritic polypyridine-ruthenium or polypyridine-osmium complex can be prepared both divergently and convergently [130] (cf. Section 2.5.2). 

Luminescent ruthenium(II) polypyridine indole complexes such as [Ru (bpy)2(bpy-indole)]2+ (37) and their indole-free counterparts have been synthesised and characterised [77]. The ruthenium(II) indole complexes display typical MLCT (djt(Ru) tt (N N)) absorption bands, and intense and long-lived orange-red 3MLCT (djt(Ru) -> Ti (bpy-indolc)) luminescence upon visible-light irradiation in fluid solutions at 298 K and in alcohol glass at 77 K. In contrast to the rhenium(I) indole complexes, the indole moiety does not quench the emission of the ruthenium(II) polypyridine complexes because the excited complexes are not sufficiently oxidising to initiate electron-transfer reactions. Emission titrations show that the luminescence intensities of the ruthenium(II) indole complexes are only increased by ca. 1.38- to... 

In related model complex studies, Isied and coworkers, have examined photo-induced (or pulse-radiolytically initiated) electron-transfer processes in which a polypyridine-ruthenium(II) complex is linked by means of a 4-carboxylato,4 -methyl,2,2 -bipyridine ligand and a polyproline chain to a [Co(NH3)5] + or [(-NH-py)Ru (NH3)5] acceptor. Chains composed of from zero to six cis-prolines have been examined. The apparent distance dependence of the electron-transfer rate constant, corrected for variations in the solvent reorganizational energy, seems to exhibit two types of distance dependence, 0.7-1A for short chains and /3 a0.3 A for long chains. A very detailed theoretical analysis of electron transfer in the complexes with four proline linkers has indicated that the electronic coupling is sensitive to conformational variations within the proline chain. ... 

Owing to the great interest in photoreduction reactions, electron transfer processes involving [Co (cage)] + and polypyridine-ruthenium(II) complexes have been extensively investigated. The rate constants for the quenching process range from 2 X 10 to 1 X 10 s at 25 °C. The yields of electron transfer products... 

Balzani et al. [9] reported metal-containing dendrimers, where the core and branching unit are built up from ruthenium complexes of a polypyridine... 

The equihbrium constant of 3.4 0.5 at 25°C, pH 7.0 for the rapid electron equilibration step (Eq. 24) in bovine COX (49) corresponds to a difference in reduction potentials between the heme-a [Fe /Fe°] and Cua [Cu /Cu ] couples of 31 4 mV, which differs from earlier values, where an eP = 276 mV was reported for heme-a and 288 mV for Cua, that is, a difference of 12mV (154). The discrepancy is not surprising, however, considering the disparate experimental conditions employed in the earlier studies O.IM phosphate buffer saturated with 1 atm CO, which maintains heme a3-CuB in the reduced state. The observed equilibrium constant of 3.4 is in good agreement with results obtained by Kobayashi et al. (151) (X 1—4) and by Einarsdottir and co-workers (K = 2) (155). In experiments where a binuclear polypyridine ruthenium(ll) complex (bound electrostaticaUy to cytochrome oxidase) was... 

In related model complex studies, Isied and coworkers, have examined photo-induced (or pulse-radiolytically initiated) electron-transfer processes in which a polypyridine-ruthenium (II) complex is linked by means of a 4-carboxylato,4 -methyl,2,2 -bipyridine ligand and a polypro-... 

Polypyridyl ruthenium complexes are known for their interesting photophysical and redox properties as well as their countless appHcations. Polypyridine ruthenium compounds display weU-defined chemistry, photochemistry, and photophysical properties they have found use as artificial light-harvesting systems for technological purposes and as... 

Figure 4 Structure of polypyridine nitrosyl ruthenium complexes. (A) c/s-[Ru(bpy)2La(NO)]" and (B) [Ru(tpy)LbNO] ...

Table 3 UV-vis spectra data for some polypyridine nitrosyl ruthenium complexes...

Table 6 Polypyridine nitrosyl ruthenium complexes quantum yield ( no) A sh photolysis at 355 nm in trifluoroacetate buffer solution, pH 2.01...

Arakawa, R Tachiyashiki, S Matsuo, T. (1995) Detection of Reaction Inferme-diates Photosubstitution of (Polypyridine)ruthenium(II) Complexes Using On-line Electrospray Mass Spectrometry. Anal. Chem. 67 4133-4138. 

Intercalation of ruthenium poly(pyridine) complexes into other layered materials has been reported (95-106). The intercalation is not as facile as in smectite systems, which is partly due to the higher charge densities of these host materials. Consequently, quantitative ion exchange of ruthenium complexes with the interlayer cations is difficult. Synthetic efforts have been made to introduce ruthenium polypyridine chelate complexes into magadiite, zirconium phosphate and phos-phonates, LDH, MnPSs, and a transition metal oxide and to control the adsorption states. 

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