Structure, electrochemistry, spectroscopy, and magnetic resonance, including high-field EPR, of {(μ-abpy)[Re(CO)3X]2}o/•−, where abpy=2,2′-azobispyridine and X=F, Cl, Br, I

Frantz, Stéphanie; Sieger, Monika; Hartenbach, Ingo; Lissner, Falk; Schleid, Thomas; Fiedler, Jan; Duboc, Carole; Kaim, Wolfgang

doi:10.1016/j.jorganchem.2008.09.034

Cited by 14 publications

(10 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…69 These transitions correspond well with observed electronic transitions for abpyc, as previously measured through spectroelectrochemical methods on ruthenium complexes. 70 The monoanionic nature of the abpy ligand was further probed by IR spectroscopy on crystalline material of 1 (Fig. S5 †).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

A rare earth metallocene containing a 2,2′-azopyridyl radical anion

et al. 2021

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

“… 69 These transitions correspond well with observed electronic transitions for abpy˙, as previously measured through spectroelectrochemical methods on ruthenium complexes. 70 …”

Section: Resultsmentioning

confidence: 99%

A rare earth metallocene containing a 2,2′-azopyridyl radical anion

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Their very low-lying π* orbitals are not only responsible for intense and low-energy metal-to-ligand charge transfer bands in corresponding complexes [ 17 , 18 , 22 , 23 , 25 , 26 , 27 , 28 , 29 , 32 , 34 , 35 , 36 , 37 ] but also for very high reduction potentials of such complexes often around 0 V (vs. NHE), allowing the facile preparation of radical complexes [ 22 , 23 , 26 , 27 , 29 , 32 , 33 , 34 , 35 , 36 , 41 ] and in total they are able to store up to two electrons [ 22 , 26 , 27 , 29 , 32 , 33 , 34 , 35 , 36 ]. In this way, the adc ligands are prototypical redox-active/non-innocent ligands [ 15 , 21 , 23 , 29 ] and can be viewed together with further bridging µ-κ 2 ,κ 2 chelate ligands with very low-lying π* orbitals such as apy = 2,2′-azobipyridine; bptz = 2,5-bis(2-pyridyl)-1,3,4,6-tetrazine, bpip = 2,5-bis(1-phenyliminoethyl)pyrazine and bpym = 2,2′-bipyrimidine ( Scheme 2 ) [ 43 , 44 , 45 , 46 , 47 , 48 , 49 , …”

Section: Introductionmentioning

confidence: 99%

Rhenium Tricarbonyl Complexes of Azodicarboxylate Ligands

et al. 2022

Self Cite

View full text Add to dashboard Cite

The excellent π-accepting azodicarboxylic esters adcOR (R = Et, iPr, tBu, Bn (CH2-C6H5) and Ph) and the piperidinyl amide derivative adcpip were used as bridging chelate ligands in dinuclear Re(CO)3 complexes [{Re(CO)3Cl}2(µ-adcOR)] and [{Re(CO)3Cl}2(µ-adcpip)]. From the adcpip ligand the mononuclear derivatives [Re(CO)3Cl(adcpip)] and [Re(CO)3(PPh3)(µ-adcpip)]Cl were also obtained. Optimised geometries from density functional theory (DFT) calculations show syn and anti isomers for the dinuclear fac-Re(CO)3 complexes at slightly different energies but they were not distinguishable from experimental IR or UV–Vis absorption spectroscopy. The electrochemistry of the adc complexes showed reduction potentials slightly below 0.0 V vs. the ferrocene/ferrocenium couple. Attempts to generate the radicals [{Re(CO)3Cl}2(µ-adcOR)]•− failed as they are inherently unstable, losing very probably first the Cl‒ coligand and then rapidly cleaving one [Re(CO)3] fragment. Consequently, we found signals in EPR very probably due to mononuclear radical complexes [Re(CO)3(solv)(adc)]•. The underlying Cl−®solvent exchange was modelled for the mononuclear [Re(CO)3Cl(adcpip)] using DFT calculations and showed a markedly enhanced Re-Cl labilisation for the reduced compared with the neutral complex. Both the easy reduction with potentials ranging roughly from −0.2 to −0.1 V for the adc ligands and the low-energy NIR absorptions in the 700 to 850 nm range place the adc ligands with their lowest-lying π* orbital being localised on the azo function, amongst comparable bridging chelate N^N coordinating ligands with low-lying π* orbitals of central azo, tetrazine or pyrazine functions. Comparative (TD)DFT-calculations on the Re(CO)3Cl complexes of the adcpip ligand using the quite established basis set and functionals M06-2X/def2TZVP/LANL2DZ/CPCM(THF) and the more advanced TPSSh/def2-TZVP(+def2-ECP for Re)/CPCMC(THF) for single-point calculations with BP86/def2-TZVP(+def2-ECP for Re)/CPCMC(THF) optimised geometries showed a markedly better agreement of the latter with the experimental XRD, IR and UV–Vis absorption data.

show abstract

“…Techniques such as spectroelectrochemistry (SEC) are extremely useful analytical tools in the quantification of molecules and have proven to be very useful when dealing with complex samples or when there is a large matrix effect [1][2][3][4][5]. SEC encompasses a group of analytical techniques that are characterized by the simultaneous recording of electrochemical and spectroscopic signals [6][7][8][9][10][11]. Among all the SEC techniques, one of the most widely used is UV/Vis absorption SEC (UV/Vis-SEC), in which during the electrochemical oxidation or reduction of a molecule, changes in the molecular absorption spectrum of the studied analytes are observed due to the electrogeneration of the reaction products and/or the consumption of the native molecule [7-9, 12, 13].…”

Section: Introductionmentioning

confidence: 99%

UV/Vis absorption spectroelectrochemistry of folic acid

Olmo

Rodriguez

Colina

et al. 2021

J Solid State Electrochem

View full text Add to dashboard Cite

UV/Vis absorption spectroelectrochemistry is a very promising analytical technique due to the complementary information that is simultaneously obtained from electrochemistry and spectroscopy. In this work, this technique is used in a parallel configuration to study the oxidation of folic acid in alkaline medium. Herein, UV/Vis absorption spectroelectrochemistry has been used to detect both the oxidation products and the folic acid consumed at the electrode/solution interface, allowing us to develop an analytical protocol to quantify vitamin B9 in pharmaceutical tablets. Linear ranges of three orders of magnitude have been achieved in basic medium (pH = 12.9), obtaining high repeatability and low detection limits. The spectroelectrochemical determination of folic acid in pharmaceutical tablets at alkaline pH values is particularly interesting because of the changes that occur in the optical signal during the electrochemical oxidation of FA, providing results with very good figures of merit and demonstrating the utility and versatility of this hyphenated technique, UV/Vis absorption spectroelectrochemistry.

show abstract

Structure, electrochemistry, spectroscopy, and magnetic resonance, including high-field EPR, of {(μ-abpy)[Re(CO)3X]2}o/•−, where abpy=2,2′-azobispyridine and X=F, Cl, Br, I

Cited by 14 publications

References 63 publications

A rare earth metallocene containing a 2,2′-azopyridyl radical anion

A rare earth metallocene containing a 2,2′-azopyridyl radical anion

Rhenium Tricarbonyl Complexes of Azodicarboxylate Ligands

UV/Vis absorption spectroelectrochemistry of folic acid

Contact Info

Product

Resources

About