Spectroelectrochemical Studies

Some halogenometalate species have been observed to have formed spontaneously during spectroelectrochemical studies in ionic liquids. For example, [MoCl ] (which is hydrolyzed in water, is coordinated by solvent in polar solvents, and has salts that are insoluble in non-polar solvents) can only be observed in basic (X(A1C13) < 0.5 chloroaluminate ionic liquids [1]. FFowever, this work has been directed at the measurement of electrochemical data, rather than exploitation of the ionic liquids as solvents for synthesis [2]. It has been shown that the tetrachloroa-luminate ion will act as a bidentate ligand in acidic X(A1C13) > 0.5 chloroaluminate ionic liquids, forming [M(AlCl4)3] ions [3]. This was also the result of the spontaneous formation of the complexes, rather than a deliberate attempt to synthesize them. 

Chen YX, Heinen M, Jusys Z, Behm RB. 2006. Kinetics and mechanism of the electrooxidation of formic acid—Spectroelectrochemical studies in a flow cell. Angew Chem Int Ed 45 981-985. 

Spectroelectrochemical studies at —60°C show a reversible one-electron reduction of the intensely coloured [Tc NX - (X = C1, Br) to [TcvNX4]2-, but the colourless reduced species have not been isolated [18]. 

Gao, G., A. S. Jeevarajan et al. (1996). Cyclic voltammetry and spectroelectrochemical studies of cation radical and dication adsorption behavior for 7,7 -diphenyl-7,7 -diapocarotene. J. Electroanal. Chem. 411 51-56. 

Tourillon and co-workers102"110 have also reported on a number of spectroelectrochemical studies, especially of electrodeposition... 

Cyano-bridged complexes include both di- and polynuclear systems. Spectroelectrochemical studies of the oxidized and reduced forms of [(bpy)2(CN)Ru(/r-CN)Ru(C (bpy)2] have been carried out. This cation and its reduced form exhibit UV-vis spectra that are consistent with the chromophores being identical. Experimental evidence indicates that the one-electron oxidation... 

In addition, spectroelectrochemical studies [55-57, 59] have undoubtedly shown that polysulfides were produced... 

Daub, Grimme, and coworkers have reported chiroptical switches based on binaphthyl boron dipyrromethane (BDP) conjugates. It is known that BDP dyes with appropriate functionalization can be reversibly oxidized and reduced.58 The CD-spectroelectrochemical studies of R-56 show a decrease in the intensity of the Cotton effect at 501 nm by applying a reduction potential to the solution. The initial CD spectrum is restored completely after reoxidation thus, the CD signal intensity at 501 nm for R-56 can be switched on and off electrochemically.59... 

A question of particular interest is whether or not the redox orbitals are essentially metal or ligand based and how this varies as one traverses the series. For example, [Ru(bipy)3]2+ (bipy = 2,2 -bipyridyl), a complex much studied for its photoredox chemistry, has been shown by electrochemical and spectroelectrochemical studies to undergo a series of reversible, ligand-localized electron-transfer reactions about the reversible metal-centred Ru VRu111 couple (reaction 2).9 10... 

Matemadombo F, Maree MD, Ozoemena K I, Westbroek P, Nyokong T (2005) Synthesis, electrochemical and spectroelectrochemical studies of octa phenyl thio-substituted phthalocyanines. J Porphyrins Phthalocyanines 9(7) 484-490... 

Brown KL, Shaw J, Ambrose M, Mottola HA (2002) Voltammetric, chronocoulometric and spectroelectrochemical studies of electropolymerized films based on Co11/11- and Zn11-4,9,16,23-tetra aminophthalocyanine effect of high pH. Microchem J 72(3) 285-298... 

Laser Raman spectroscopy has played a major role in the study of electrochemical systems (see Section 3.4). The technique provides molecular-specific information on the structure of the solid-solution interfaces in situ and is particularly suited for spectroelectrochemical studies of corrosion and surface film formation. Metals such as Pb, Ag, Fe, Ni, Co, Cu, Cr, Ti, Au and Sn, stainless steel and other alloys in various solutions have been studied by the technique. 

Figure 7-10 Experimental setup for laser Raman spectroelectrochemical studies. (Reprinted from Ref. 5 by permission of Kluwer Academic Publishers.)...

Taniguchi I, Kai A, Mie Y et al (2004) Spectroelectrochemical study on a function of nitrophorin-4, a heme protein of insecto. Abstract no. 731, 205th meeting of the Electrochemical Society... 

Developing the capability to make homemade glove boxes may be very important for special needs, such as spectroelectrochemical studies. For instance, FTIR spectroscopy, AFM or STM measurements of active metal electrodes are much more accurate and reliable when done inside a glove box. To enable such measurements, the instruments should be installed in glove boxes that are specially designed for them. We ourselves built special glove boxes for a FTIR... 

It should be emphasized that a noble gas environment containing atmospheric contaminants at the ppm level cannot be considered inert for sensitive electrodes such as active metals. The inertness of a glove box atmosphere can be sufficient for preparation and work with nonaqueous solutions at low H20, 02, C02 and N2 contamination levels. Work with active metal electrodes, especially when spectroelectrochemical studies are important, requires special electrode surface preparation, as described later. As a rule, a glove box may be sufficient for maintaining a low contamination level in bulk materials, but not on active surfaces. 

Nuclear magnetic resonance (NMR) spectroscopy — Nuclear magnetic resonance (NMR) spectroscopy of atoms having a nonzero spin (like, e.g., H, 13C) is an extremely powerful tool in structural investigations in organic and inorganic chemistry. Beyond structural studies atoms observable with NMR can also be used as probes of their environment. Thus NMR may be employed for in situ spectroelectrochemical studies [i]. Cell designs for in situ NMR spectroscopy with electrochemical cells are scant. Because of the low sensi-... 

More complete assignment of the M—S stretching modes in M[S2C2(CN)2]3 2 (M = V, Mo, W) requires parallel far-IR studies and/or metal isotope shift data, which are not available for the Mo and W complexes. Far-IR spectroelectrochemical studies of V[S2C2(CN)2]3 2- revealed redox... 

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