Facile Interconversion Research Articles

How Do Differences in Electronic Structure Affect the Use of Vanadium Intermediates as Mimics in Nonheme Iron Hydroxylases?

We study active-site models of nonheme iron hydroxylases and their vanadium-based mimics using density functional theory to determine if vanadyl is a faithful structural mimic. We identify crucial structural and energetic differences between ferryl and vanadyl isomers owing to the differences in their ground electronic states, i.e., high spin (HS) for Fe and low spin (LS) for V. For the succinate cofactor bound to the ferryl intermediate, we predict facile interconversion between monodentate and bidentate coordination isomers for ferryl species but difficult rearrangement for vanadyl mimics. We study isomerization of the oxo intermediate between axial and equatorial positions and find the ferryl potential energy surface to be characterized by a large barrier of ca. 10 kcal/mol that is completely absent for the vanadyl mimic. This analysis reveals even starker contrasts between Fe and V in hydroxylases than those observed for this metal substitution in nonheme halogenases. Analysis of the relative bond strengths of coordinating carboxylate ligands for Fe and V reveals that all of the ligands show stronger binding to V than Fe owing to the LS ground state of V in contrast to the HS ground state of Fe, highlighting the limitations of vanadyl mimics of native nonheme iron hydroxylases.

Quantitative analysis of the glutathione pathway cellular metabolites by targeted liquid chromatography-tandem mass spectrometry.

Glutathione, its biosynthesis intermediates, and other thiol metabolites are of central relevance for the redox homeostasis of cells. Their analysis is critical due to the facile interconversion of redox pairs during sampling, sample preparation, and data acquisition, in particular in the electrospray ionization interface. In this work, we propose a fast-targeted liquid chromatography-tandem mass spectrometry method to accurately analyze 14 metabolites from the glutathione pathway. N-Ethylmaleimide reagent is added with the extraction solvent and instantly stabilizes the thiol-redox state by derivatization. Liquid chromatographic separation of the analytes was performed on a sub-2μm superficially porous hydrophilic interaction liquid chromatography column with sulfobetaine chemistry. Tandem mass spectrometry with triple-quadrupole mass spectrometry in multiple-reaction monitoring acquisition mode allowed sensitive detection of the targeted metabolites with limits of quantification in the range of 5-25nM. Run times of 3min enable a high throughput analysis of cellular samples. For calibration, a 13 C-labelled cell extract was used as an internal standard. The method was validated and the concentrations of glutathione and its biosynthesis intermediates were determined in HeLa cells.

A laser flash photolysis study of the free radical chemistry of lipoic acid and dihydrolipoic acid.

The free radical chemistry of lipoic acid (LA) and dihydrolipoic acid (DHLA) intersect at the point where DHLA loses hydrogen to a good hydrogen abstracting radical, while LA reacts with strongly reducing ketyl radicals capable of donating a hydrogen atom. While aliphatic thiyl radicals have an absorbance at ~ 330nm, the resulting radical, formally also a thiyl radical has distinct spectroscopic properties with a maximum at 385nm, suggesting that the two sulphur centres interact strongly with each other as part of the chromophore. The reactions that form these radicals were studied by laser flash photolysis that revealed DHLA as an excellent hydrogen donor, while LA is an excellent hydrogen acceptor. The results support earlier evidence that the real antioxidant is DHLA, while LA is not; yet, the reported facile interconversion of the two molecules suggests that LA may be a better supplement, given its shelf stability, compared with a far more difficult-to-handle DHLA.

Crystallographic studies of fac- and mer-isomers of Cu[1,4,7,10,13,16-hexaazacyclooctadecane]2+. Influence of counterion and crystallization solvent on crystal structure and dynamic Jahn-Teller effects. Computational studies of structures, energetics, and mechanism of mer-fac isomerization

The syntheses and crystal structures of mer- and fac-isomers of [Cu(18N6)]2+(X−)2 are reported (18 N6 = 1,4,7,10,13,16-hexaazacyclooctadecane; X− = BF4−, ClO4−, NO3−) and compared to a previously reported example (X− = Cl−). Solution structures of the [Cu(18N6)]2+ dication in MeNO2 or MeOH are shown by FT-IR to be almost exclusively mer, and simple evaporation of these solutions or crystallization using Et2O co-solvent also afford the solid mer-salts. However, using C6H6 or CCl4 as crystallization co-solvents afforded the corresponding fac-isomers of the BF4− and ClO4− salts, in which the anions and the symmetrical solvent occupy locations on the crystallographic 3-fold axis. Similar treatment of the less symmetrical NO3− salts affords the mer-isomer without inclusion of C6H6. The solid-state structures of the mer-isomers each exhibit the anticipated tetragonal Jahn-Teller distortions, with two longer Cu-N bonds. In contrast the fac-isomers all show internally identical Cu-N distances, due to a dynamic exchange between Jahn-Teller distorted structures in the crystal. Density Functional Theory (DFT) is used to provide rationalizations of these observations and to elucidate an energetically feasible mechanistic pathway for the facile interconversion of mer and fac isomers in solution.

Targeting Individual Tautomers in Equilibrium by Resonant Inelastic X-ray Scattering

Tautomerism is one of the most important forms of isomerism, owing to the facile interconversion between species and the large differences in chemical properties introduced by the proton transfer connecting the tautomers. Spectroscopic techniques are often used for the characterization of tautomers. In this context, separating the overlapping spectral response of coexisting tautomers is a long-standing challenge in chemistry. Here, we demonstrate that by using resonant inelastic X-ray scattering tuned to the core excited states at the site of proton exchange between tautomers one is able to experimentally disentangle the manifold of valence excited states of each tautomer in a mixture. The technique is applied to the prototypical keto–enol equilibrium of 3-hydroxypyridine in aqueous solution. We detect transitions from the occupied orbitals into the LUMO for each tautomer in solution, which report on intrinsic and hydrogen-bond-induced orbital polarization within the π and σ manifolds at the proton-transfer site.

Thermal Rearrangement of Azulenes to Naphthalenes: A Deeper Insight into the Mechanisms.

The thermal rearrangement of azulene to naphthalene has been the subject of several experimental and computational studies. Here, we reexamine the proposed mechanisms at the DFT level. The use of different functionals showed that the HF-exchange contribution significantly affects reaction energies and barrier heights. Accordingly, all proposed pathways were investigated with the optimal method, M06-2X/6-311+G(d,p), which confirms the norcaradiene-vinylidene mechanism (A) as the dominant unimolecular route (Ea ≈ 76 kcal/mol) able to account for the major products of pyrolyses using 13C- or substituent-labeled azulenes. Moreover, a facile vinylidene-acetylene interconversion will scramble the terminal carbon atoms in the vinylidene. Several other potential intramolecular reaction mechanisms (B-E) are ruled out because of higher activation energies (>84 kcal/mol) and failure to reproduce the results obtained with substituted and 13C-labeled azulenes and benzazulenes. These experimental results also demonstrate that the proposed free radical or H atom-induced intermolecular methylene walk and spiran mechanisms cannot be major contributors, especially under flash vacuum pyrolysis conditions.

A Brønsted Acidic Gallium Hydride: Facile Interconversion of NNNN-Macrocycle Supported [GaI ]+ and [GaIII H]2.

Protonolysis of [Cp*M] (M=Ga, In, Tl) with [(Me4TACD)H][BAr4 Me] (Me4TACD=N,N′,N′′,N′′′‐tetramethyl‐1,4,7,10‐tetraazacyclododecane; [BAr4 Me]−=[B{C6H3‐3,5‐(CH3)2}4]−) provided monovalent salts [(Me4TACD)M][BAr4 Me], whereas [Cp*Al]4 yielded trivalent [(Me4TACD)AlH][BAr4 Me]2. Protonation of [(Me4TACD)Ga][BAr4 Me] with [Et3NH][BAr4 Me] gave an unusually acidic (pK a(CH3CN)=24.5) gallium(III) hydride dication [(Me4TACD)GaH][BAr4 Me]2. Deprotonation with IMe4 (1,3,4,5‐tetramethyl‐imidazol‐ylidene) returned [(Me4TACD)Ga][BAr4 Me]. These reversible processes occur with formal two‐electron oxidation and reduction of gallium. DFT calculations suggest that gallium(I) protonation is facilitated by strong coordination of the tetradentate ligand, which raises the HOMO energy. High nuclear charge of [(Me4TACD)GaH]2+ facilitates hydride‐to‐metal charge transfer during deprotonation. Attempts to prepare a gallium(III) dihydride cation resulted in spontaneous dehydrogenation to [(Me4TACD)Ga]+.

Ein Brønsted‐saures Galliumhydrid: Einfache Umwandlung von NNNN‐Makrocyclus‐geträgertem [GaI]+ in [GaIIIH]2+

AbstractProtonolyse von [Cp*M] (M=Ga, In, Tl) mit [(Me4TACD)H][BAr4Me] (Me4TACD=N,N′,N′′,N′′′‐Tetramethyl‐1,4,7,10‐tetraazacyclododecan; [BAr4Me]−=[B{C6H3‐3,5‐(CH3)2}4]−) ergab Salze der einwertigen Metalle [(Me4TACD)M][BAr4Me], während [Cp*Al]4 das dreiwertige Hydridkation [(Me4TACD)AlH][BAr4Me]2 lieferte. Protonierung von [(Me4TACD)Ga][BAr4Me] mit [Et3NH][BAr4Me] führte zu einem ungewöhnlich sauren (pKa(CH3CN)=24.5) Gallium(III)hydrid‐Dikation [(Me4TACD)GaH][BAr4Me]2. Deprotonierung mit IMe4 (1,3,4,5‐Tetramethyl‐imidazol‐yliden) ergab [(Me4TACD)Ga][BAr4Me]. Diese reversiblen Prozesse treten bei der formalen Zwei‐Elektronen‐Oxidation und ‐Reduktion von Gallium auf. DFT‐Rechnungen legen nahe, dass eine starke Koordination des vierzähnigen Liganden die HOMO‐Energie von Gallium(I) erhöht, was die Protonierung erleichtert. Die hohe Kernladung von [(Me4TACD)GaH]2+ erleichtert den Ladungstransfer vom Hydrid zum Metall während der Deprotonierung. Die versuchte Herstellung eines Gallium(III)dihydrid‐Kations führte zu einer spontanen Dehydrierung zu [(Me4TACD)Ga]+.

Insight into peroxidase and polyphenol oxidase mimic activity of spinel ferrite nanoparticles and their GO composites

Present work reports the comparative evaluation of MFe2O4 (M = Mn, Co and Cu) nanoparticles (NPs), graphene oxide (GO) and their nanocomposite (NC) for their intrinsic peroxidase and polyphenol oxidase (PPO) mimic activity of followed by the catalytic sensing of H2O2. Pure and doped MFe2O4 NPs were screened initially for peroxidase and PPO mimic activity. Among the tested metal ferrite NPs, MnFe2O4 NPs showed the highest enzyme mimic activity for both the enzymes. Thus, MnFe2O4-GO NC was synthesized by the facile ultrasonication method and characterized using FT-IR and XRD techniques. TEM micrographs of NC showed that MnFe2O4 NPs were anchored on GO sheets with lesser agglomeration than bare ferrite NPs. SEM-EDX confirmed the presence of MnFe2O4 and GO in NC. The greater surface area of NC as compared to pristine NPs was confirmed from BET analysis. MnFe2O4 NPs displayed highest peroxidase and PPO mimic activity followed by NC and GO. The results were correlated with the facile inter-conversion of Mn2+-Mn3+ ions. Thus, ease of inter-conversion of oxidation state was the dominating factor of highest activity of MnFe2O4 NPs rather than the surface area. The colorimetric detection of H2O2 was also achieved in the range 0.2 mM–1.0 mM H2O2. In-situ trapping experiments confirmed that OH. radicals were major active species involved in peroxidase mimic activity. The reaction mechanisms for both the reactions were proposed. Kinetic studies were performed and data was analysed using Michaelis Menten equation. The values of Vmax and Km for both the reactions proved MnFe2O4 NPs as potential oxidase mimic for a wide range of potential applications.

Excited state dynamics of a spontaneously generated TTF radical cation inside a water-soluble nanocage.

Supramolecular cavities have been traditionally used to stabilize reactive redox intermediates. Recently with the success of multiple new photoredox catalytic strategies that use supramolecular cages, there is a growing demand for photogeneration strategies of diverse reactive intermediates inside confined spaces, which will drive enzyme-like catalysis in real time. Here we report the excited state dynamics of a redox-active TTF radical cation and its corresponding dimethyl-derivative DiMeTTF inside a confined supramolecular cavity. We prepare the radical cation by spontaneous oxidation of neutral TTF upon incarceration inside a water-soluble nanocage Pd6L412+, and characterize it with a combination of resonance Raman and electron paramagnetic resonance spectroscopy. Using broadband transient absorption spectroscopy, we demonstrate that the confined native TTF radical cation and its dimethyl derivative upon photoexcitation rapidly de-excite to form the hot ground state, thereby inhibiting further oxidation to a TTF+2 dication. We discuss our results in the context of excited state crossings of the radical cation potentials as well as modifying the cage energetics to generate a stable dication. Our work has important implications for the usage of such radical cations for photoactivated catalysis.

Structure of a dimer of the Sulfolobus solfataricus MCM N-terminal domain reveals a potential role in MCM ring opening.

Cells strongly regulate DNA replication to ensure genomic stability and prevent several diseases, including cancers. Eukaryotes and archaea strictly control DNA-replication initiation by the regulated loading of hexameric minichromosome maintenance (MCM) rings to encircle both strands of the DNA double helix followed by regulated activation of the loaded rings such that they then encircle one DNA strand while excluding the other. Both steps involve an open/closed ring transformation, allowing DNA strands to enter or exit. Here, the crystal structure of a dimer of the N-terminal domain of Sulfolobus solfataricus MCM with an intersubunit interface that is more extensive than in closed-ring structures, while including common interactions to enable facile interconversion, is presented. It is shown that the identified interface could stabilize open MCM rings by compensating for lost interactions at an open neighbor interface and that the prior open-ring cryo-EM structure of MCM loading has a similar extended interface adjacent to its open interface.

CH4 Oxidation Activity in Pd and Pt–Pd Bimetallic Catalysts: Correlation with Surface PdOx Quantified from the DRIFTS Study

For Pd-based catalysts, facile and fast interconversion between Pd and PdO occurs continuously during the CH4 oxidation reaction, which makes it challenging to determine active sites. Herein, we re...

Surface Engineering Cerium Oxide Nanoparticles for Biosensor Performance: Influence of Redox-Active, Oxo-Anion Ligand Modification on Sensitivity

Nanoscale cerium oxide surface chemistry has been studied intensively due to its pronounced activity in various catalytic applications. The material’s surface reactivity is generally attributed to oxygen vacancy density and the facile inter-conversion between Ce3+ and Ce4+ redox states. However, experimental and theoretical investigations suggest a more intricate surface chemistry. In this study, cerium oxide nanoparticles (CNPs) were modified with high-valence oxo-anions to modulate surface electronic structure and chemical interactions with medically-relevant analytes. Changes to the surface chemical environment were assessed via x-ray photoelectron spectroscopy (XPS) (e.g. binding energy shifts; peak number and character), while charge transfer properties were characterized through electrochemical impedance spectroscopy and circuit fitting (following ligand@particle electrophoretic deposition in dH2O onto glassy carbon electrodes, GCE). Further, the influence of vacancy density and ligand interaction was characterized via doping Sm3+ into CNPs in varying dopant fractions (0-15 mol%; oxygen vacancy concentration increases linearly with Sm3+ concentration). From here, ligand@CNP-modified GCEs were assessed for amperometric (via chronoamperometry) and voltametric (via square-wave voltammetry) sensitivity towards catechols, ascorbic acid, and glucose in phosphate buffered saline. Time of response and selectivity (in presence of structural chemical analogues) were also assessed in similar conditions. Relative sensitivities/performances were analyzed and compared in relation to XPS and electroanalysis trends/characters for future design of optimized biosensor platforms.

Butyltin Keggin Ion with a Rare Four-Coordinate Ca Center.

Alkyltin clusters are exploited in nanolithography for the fabrication of microelectronics. The alkyltin Keggin family is unique among Keggin clusters across the periodic table; its members appear to favor the lower-symmetry β and γ isomers rather than the highly symmetrical α and ε isomers. Therefore, the alkyltin Keggin family may provide important fundamental information about the formation and isomerization of Keggin clusters. We have synthesized and structurally characterized a new butyltin Keggin cluster with a tetrahedral Ca2+ center, fully formulated [(BuSn)12(CaO4)(OCH3)12(O)4(OH)8]2+ (β-CaSn12). The synthesis is a simple one-step process. Extensive solution characterization including electrospray ionization mass spectrometry, small-angle X-ray scattering, and multinuclear (1H, 13C, and 119Sn) nuclear magnetic resonance shows β-CaSn12 is essentially phase-pure and stable. This differs from the previously reported Na-centered analogues that always form a mixture of β and γ isomers, with facile interconversion. Therefore, this study has clarified prior confusion over complex spectroscopic and crystallographic characterization of the Na-centered analogues. Density functional theory calculations showed the following stability order: γ-CaSn12 < γ-NaSn12 < β-CaSn12 < β-NaSn12. The β analogue is always more stable than the γ analogue, consistent with experiment. Notable outcomes of this study include a rare tetrahedral Ca coordination, a Na-free alkyltin cluster (important for microelectronics manufacturing), and a better understanding of Keggin families built of different metal cations.

Kinetics of aromatics hydrogenation on HBEA

Zeolite HBEA catalyzes hydrogenation of aromatic hydrocarbons—methyl-substituted benzenes (benzene and toluene), alkenyl-substituted benzenes (styrene), and polycyclics (naphthalene)—in presence of excess H2 at high-temperatures (573–748 K) with rates that depend linearly on aromatic and H2 pressures. The observed kinetic behavior can be rationalized based on a sequence of elementary steps where the first hydrogenation step of the adsorbed benzenic intermediate is rate-determining while subsequent hydrogenation and desorption steps are quasi-equilibrated and H+ is the most abundant surface species. Styrene hydrogenation exhibits the highest rates among the aromatics considered and results exclusively in ethylbenzene synthesis; in contrast, benzene/toluene and naphthalene hydrogenation results in formation of their triply-hydrogenated five-membered ring and doubly-hydrogenated ring open analogs, respectively. Based on independent studies involving co-reaction of cyclohexene and 1-methyl-1-cyclopentene with H2, we infer their facile interconversion and hydrogenation to methylcyclopentane implying that conversion of benzene to methylcyclopentane likely occurs via intervening formation of both five- and six-membered ring intermediates. Taken together, these studies demonstrate feasibility of aromatics hydrogenation and propensity of benzenic rings in these hydrocarbons to undergo ring reduction or ring opening during their activation with H2 on Brønsted acid zeolites.

An Adaptable N-Heterocyclic Carbene Macrocycle Hosting Copper in Three Oxidation States.

A neutral hybrid macrocycle with two trans‐positioned N‐heterocyclic carbenes (NHCs) and two pyridine donors hosts copper in three oxidation states (+I–+III) in a series of structurally characterized complexes (1–3). Redox interconversion of [LCu]+/2+/3+ is electrochemically (quasi)reversible and occurs at moderate potentials (E 1/2=−0.45 V and +0.82 V (vs. Fc/Fc+)). A linear CNHC‐Cu‐CNHC arrangement and hemilability of the two pyridine donors allows the ligand to adapt to the different stereoelectronic and coordination requirements of CuI versus CuII/CuIII. Analytical methods such as NMR, UV/Vis, IR, electron paramagnetic resonance, and Cu Kβ high‐energy‐resolution fluorescence detection X‐ray absorption spectroscopies, as well as DFT calculations, give insight into the geometric and electronic structures of the complexes. The XAS signatures of 1–3 are textbook examples for CuI, CuII, and CuIII species. Facile 2‐electron interconversion combined with the exposure of two basic pyridine N sites in the reduced CuI form suggest that [LCu]+/2+/3+ may operate in catalysis via coupled 2 e−/2 H+ transfer.

Superoxide dismutase mimic activity of spinel ferrite $${\hbox {MFe}}_{2} {\hbox {O}}_{4}$$ MFe 2 O 4 ( $$\hbox {M} = \hbox {Mn}$$ M = Mn , Co and Cu) nanoparticles

In the present study, superoxide dismutase (SOD) mimic activity of ferrite nanoparticles (NPs), having a formula \({\hbox {MFe}}_{2} {\hbox {O}}_{4}\) (\(\hbox {M} = \hbox {Mn}\), Co and Cu) was investigated. Spinel ferrite NPs were synthesized by employing sol–gel methodology and characterized using scanning electron microscopy, X-ray diffraction, BET analysis and Fourier transform infrared spectroscopy techniques. BET analysis revealed that the surface area of ferrite NPs ranged from \(0.43{-}23.49 \, {\hbox {m}}^{2} \, {\hbox {g}}^{-1}\). Enzyme mimic activity was compared using SOD as a model enzyme. \({\hbox {CuFe}}_{2} {\hbox {O}}_{4}\, \hbox {NPs}\) exhibited a maximum activity followed by \({\hbox {CoFe}}_{2} {\hbox {O}}_{4}\) and \({\hbox {MnFe}}_{2} {\hbox {O}}_{4}\, \hbox {NPs}\). The results were correlated with a facile interconversion of the oxidation state leading to a stable electronic configuration in \({\hbox {CuFe}}_{2} {\hbox {O}}_{4}\, \hbox {NPs}\). Optimum pH and contact time was 1 and 3 min respectively. Kinetic studies were performed under optimum conditions and data were analysed using the Michaelis Menten equation. The values of \(V_{\mathrm{max}} \, (0.77 \, {\hbox {s}}^{-1})\) and \(K_{\mathrm{m}}\) (4.20 mM) proved \({\hbox {CuFe}}_{2} {\hbox {O}}_{4}\, \hbox {NPs}\) as potential SOD mimic for a wide range of applications.

Toward Phase and Catalysis Control: Tracking the Formation of Intermetallic Nanoparticles at Atomic Scale

Summary Intermetallic nanoparticles (iNPs) have yielded enormous successes in catalytic applications by the formation of ordered phases. However, atomic-level understanding of the alloying mechanism, which plays a pivotal role in controlling intermetallic phases and tailoring their catalytic properties, is still elusive. In this study, we discovered a consecutive formation of ordered Pt3Sn and PtSn phases during the growth of Pt-Sn iNP inside a well-defined nano-reactor at elevated temperature by using in situ scanning transmission electron microscopy. We found that the surface-mediated diffusion of Sn controls overall dynamics of the reaction, while the unique coherent interfacial structure is determinative for the PtSn transformation. We then further controlled the phase selection of Pt-Sn iNPs and demonstrated their distinguishable catalytic behaviors. Our findings not only provide detailed experimental evidence on the alloying mechanism in intermetallic nanoscale systems but also pave the way for mechanistic control of synthesis and catalytic properties of iNPs.

The α-cell in diabetes mellitus.

Findings from the past 10 years have placed the glucagon-secreting pancreatic α-cell centre stage in the development of diabetes mellitus, a disease affecting almost one in every ten adults worldwide. Glucagon secretion is reduced in patients with type 1 diabetes mellitus, increasing the risk of insulin-induced hypoglycaemia, but is enhanced in type 2 diabetes mellitus, exacerbating the effects of diminished insulin release and action on blood levels of glucose. Abetter understanding of the mechanisms underlying these changes is therefore an important goal. RNA sequencing reveals that, despite their opposing roles in the control of blood levels of glucose, α-cells and β-cells have remarkably similar patterns of gene expression. This similarity might explain the fairly facile interconversion between these cells and the ability of the α-cell compartment to serve as a source of new β-cells in models of extreme β-cell loss that mimic type 1 diabetes mellitus. Emerging data suggest that GABA might facilitate this interconversion, whereas the amino acid glutamine serves as a liver-derived factor to promote α-cell replication and maintenance of α-cell mass. Here, we survey these developments and their therapeutic implications for patients with diabetes mellitus.

X-ray crystallographic, spectroscopic and electrochemical properties of a bi-stable di-2-thienyl ketone 2,4-dinitrophenyl hydrazone (dtkdnph)

Di-2-thienyl ketone 2,4-dinitrophenyl hydrazone (dtkdnph), obtained from the acid-catalyzed condensation of di-2-thienyl ketone (dtk) with 2,4-dinitrophenylhydrazine, exhibits rich phyisco-chemical properties. X-ray structural analysis on a single crystal of dtkdnph grown from a dmso solution confirmed its identity, revealed non-coplanar thienyl rings, and a web of non-covalent interactions. Spectroscopic measurements in protophilic solvents, hydrogen bond acceptors, such as dmso or dmf, disclosed high sensitivity of dtkdnph to its surrounding, established an equilibrium between dtkdnph and dtkdnph.S (S = solvent) and showed substrates in concentrations as low as 1 × 10−9 M can be detected using protophilic solutions of dtkdnph. Variable temperature studies confirmed the facile inter-conversion between dtkdnph and dtkdnph.S and changes in enthalpy (ΔHø) of −11.77 ± 0.66, 13.55 ± 0.66 kJmol−1, entropy (ΔSø) of −37.21 ± 2.00 and 33.55 ± 2.00 JK−1mol−1 and free energy (ΔGø) of −0.68 and 3.5 kJmol−1 were calculated in dmf and dmso, respectively. Electrochemical measurements divulged solvent dependence, and electrochemical decomposition following the first electron transfer.