Temperature-dependent 1H Research Articles

СТРУКТУРА И ВНУТРИМОЛЕКУЛЯРНАЯ ПОДВИЖНОСТЬ НЕКОТОРЫХ ПРОИЗВОДНЫХ БИС(ТИО)ФОСФОРИЛИРОВАННЫХ АМИДОВ В РАСТВОРАХ CCl4, CD2Cl2 И CD3CN

The structure and intramolecular mobility of some derivatives of bis(thio)phosphorylated amides in CCl4, CD2Cl2, and CD3CN solutions were examined by 1H and 31P NMR spectroscopy. A comparative analysis of the temperature-dependent 1H and 31P NMR spectra of the studied compounds with symmetric and asymmetric substitution at phosphorus atoms was carried out. Various intramolecular processes were identified – rotation around C-N bonds, conformational transformations of molecules, tautomerism, and phosphorylotropic rearrangement with the formation of various conformational forms. It was shown that a dynamic equilibrium of several forms is reached, with the amide (phosphazo-) form having a clear advantage.

Ligand Coverage and Exciton Delocalization Control Chiral Imprinting in Perovskite Nanoplatelets

Chiral perovskites have recently generated significant interest, yet little is known about how their chiro-optical properties arise. In this study, chiral methylammonium lead halide perovskite nanoplatelets (NPLs) with varied halide and ligand compositions are prepared by using direct synthetic methods. Circular dichroism (CD) and 1H NMR studies find a nonlinear relationship between the chiroptical properties and the ratio of chiral phenylethylammonium (PEA) to achiral octylamine (OA) ligands on the NPL surface. We use density functional theory (DFT) computations and a chiral imprinted particle-in-a-box model to rationalize the experimentally observed CD spectra, and we find that the saturation of the induced chirality depends on the size of the perovskite exciton relative to the size of the ligand moleclues. Temperature-dependent CD and 1H NMR studies, combined with DFT analysis, show that both the CD intensity and sign depend strongly on the structure and orientation of the ligands. This work reveals the complex nature of chiral imprinting in perovskite nanostructures and establishes a simple physical model for ligand-induced chiral imprinting to guide the further development of chiral materials.

Solution behavior of half sandwich ruthenium(II) complexes ligated by sym N,N'-diarylthiourea: Structural aspects and temperature dependent NMR

The bridge-splitting reaction of [(η6-C10H14)RuCl(μ-Cl)]2 (η6-C10H14 = η6-p-cymene) with sym N,N′-diarylthiourea (2 equiv.), (ArNH)2C=S in toluene at room temperature afforded [(η6-C10H14)RuCl2{(S)C(NHAr)2}]⋅xH2O (sym = symmetrical; Ar = C6H5 (1), 2-MeC6H4 (2), 2,4-Me2C6H3 (3), 2,5-Me2C6H3 (4), 2,6-Me2C6H3 (5), and 2,6-iPr2C6H3 (6); x = none (1–2, and 4–6) and 1 (3)) in 86%−95% yields. However, the aforementioned reaction afforded [(η6-C10H14)RuCl{(S)C(NHAr)2}2]+[(ArNH)2C(S)⋅Cl]–⋅toluene (Ar = 2,6-Me2C6H3; 7) in 90% yield when carried out with four equiv of (ArNH)2C=S. The mode of coordination in all the Ru(II) complexes was confirmed by spectroscopic methods and X-ray crystallography. In solution, complexes 2 and 7 exhibited two isomers in about 2:1 and 1:0.15 ratios respectively and confirmed by a temperature dependent 1H NMR spectral titration. The spectral pattern was attributed to the rotation through C−N(H)Ar single bond of thiourea in 2 and sulfur inversion of one of the coordinated thiourea in 7. Various reasons that are responsible for the presence of two isomers for 2 and 7 in solution have been discussed.

The heterospin cobalt complexes: peculiarities of high-resolution NMR spectra

The high-resolution 1H and 13C NMR spectra (CHCl3 solution) of sterically non-rigid heterospin complexes CoL2, CoL2-dipy, and CoL2-phen (where L is 4-(3′,3′,3′-trifluoro-2′-oxopropylidene)-2,2,5,5-tetramethyl-3-imidazolidine-1-oxyl) have been studied. The specific of the NMR phenomenon in paramagnetic systems is briefly analyzed. It is shown that the NMR spectra modified by hyperfine coupling can be successfully employed for investigation of the complexation processes. In accordance with the common protocols, the 1H and 13C NMR signals are assigned using the information on 13С – 1Н spin-spin coupling. In addition, the preliminarily recorded 1H and 13C NMR spectra of radical L are also used in the work.The temperature dependences of 1H and 13C paramagnetic shifts in the complexes under study have been obtained. A fundamental feature of these dependences is that they obey to the Curie law in a fairly wide temperature range (up to 100 °C). This observation can be used to control intramolecular processes of sterically nonrigid heterosystems in solutions.

Stereostructure Dependence Phenomenon on the Self-Assembly of Ala-Ala-Ala Lipotripeptides.

A series of lipotripeptide stereoisomers based on alanine were synthesized, and their self-assembling behaviors were studied by means of circular dichroism spectra, ATR-IR, temperature-dependent 1H NMR, and X-ray diffraction patterns. In the mixed solvent of hexafluoroisopropanol/H2O (1/9, v/v), eight lipotripeptides were able to self-assembled into nanoflakes or nanoribbons driven by the hydrophobic association of alkyl chains, intermolecular hydrogen bonding among carboxyl groups at C-terminal and amide groups of alanine moieties in the peptide segment. It was found that the stacking chirality of carbonyl groups was determined by the chirality of alanine residue at C-terminal (i.e., "C-terminal determination" rule). Moreover, our research also highlighted the intermolecular hydrogen bonding on amide groups of each alanine residue, terminal carboxyl as well as the molecular packing structures can be subtly manipulated by changing the stereochemical sequence of peptide segment.

Front Cover: Interconversion of tetrahedral [(M)4∩{Mg4(L1)6}]/[In4(L2)4] and cyclic [In6Cl6(L3)6]. Enantiotopization of diastereotopic protons monitored by means of VT 1H NMR spectroscopy (Eur. J. Inorg. Chem. 4/2022)

The Front Cover shows the enantiotopization of diastereotopic groups via enantiomerization using isopropyl-COT as an example. This fundamental phenomenon is the common thread running through the manuscript. Impressively, this is also shown by the dynamic temperature dependent (VT) 1H NMR spectrum for the diastereotopic methylene protons (green) of meso-[In4(L)4)] 1. Because of the helitopic ligands (L)3−, all signals are triplicated. Due to mesomerization (Bailar twist/helitopization) of the identical twins (2Δ,2Λ)(2P,2 M)-1 ⇌ (2Λ,2Δ)(2 M,2P)-1′ all signals coalesce. More information can be found in the Minireview by R. W. Saalfrank and co-workers.

Reversible mechanochromic studies on AIE-inspired smart materials and their applications in HCHO sensing.

Smart fluorescent materials that respond to external stimuli have received more and more attention because of their excellent optical properties in the field of anti-counterfeiting, information security and fluorescence sensing. Herein, we reported a new stimulus-responsive material, {[Zn4(TCPE)(HTCPE)(DMA)3(OH)(H2O)2]·2DMA·2H2O}n (HPU-21), which showed a series of fluorescence changes under the influence of temperature, pressure and solvents. Combined with the temperature-dependent fluorescence, 1H NMR and 13C NMR spectra, TEM and powder X-ray diffraction results, the fluorescence transformation was mainly attributed to the changes in the twisted ethyl core and the multiple rotational phenyl rings, as well as the aggregation degree. Based on these findings, we designed an adjustable formaldehyde probe with excellent performance. The detection limit of formaldehyde in aqueous solutions is calculated as 35 ppb, which is much lower than the concentration that is harmful to health (20 ppm). The extremely high sensitivity to formaldehyde makes it have potential application prospects in practical formaldehyde detection.

Aqueous Synthesis of Upper Critical Solution Temperature and Lower Critical Solution Temperature Copolymers through Combination of Hydrogen-Donors and Hydrogen-Acceptors.

The synthesis of thermo-responsive polymers from non-responsive and water-soluble monomers has great practical advantages but significant challenges. Herein, the authors report a novel aqueous copolymerization strategy to prepare polymers with tunable upper critical solution temperature (UCST) or lower critical solution temperature (LCST) from non-responsive monomers. Acrylic acid (AAc), N-vinylpyrrolidone (NVP), and acrylamide (AAm) are copolymerized in water, yielding copolymers with UCST behavior. Interestingly, by simply replacing AAm with its methylated homologue, dimethyl acrylamide (DMA), the thermo-responsiveness of the copolymers is converted into LCST-type. The cloud points of the copolymers can be tuned rationally with their monomer ratios and the condition of the solvent. The UCST property of the poly(AAc-NVP-AAm) comes from the AAc-AAm and AAc-NVP hydrogen-bonds, while the LCST property of poly(AAc-NVP-DMA) originates from the hydrophobic aggregation of AAc-NVP complex and DMA, as indicated by temperature-dependent 1 H NMR and dynamic light scattering.

Stimuli-Responsive Zwitterionic Core–Shell Microgels for Antifouling Surface Coatings

Fouling on filtration membranes is induced by the nonspecific interactions between the membrane surface and the foulants, and effectively hinders their efficient use in various applications. Here, we established a facile method for the coating of membrane surface with a dual stimuli-responsive antifouling microgel system enriched with a high polyzwitterion content. Different poly(sulfobetaine) (PSB) zwitterionic polymers with defined molecular weights and narrow dispersities were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization and integrated onto poly(N-vinylcaprolactam) (PVCL) microgels via a controlled dosage of a cross-linker, adapting a precipitation polymerization technique to obtain a core-shell microstructure. Increasing the PSB macro-RAFT concentration resulted in a shift of both upper critical solution temperature and lower critical solution temperature toward higher temperatures. Cryogenic transmission electron microscopy at different temperatures suggested the formation of a core-shell morphology with a PVCL-rich core and a PSB-rich shell. On the other hand, the significant variations of different characteristic proton signals and reversible phase transitions of the microgel constituents were confirmed by temperature-dependent 1H NMR studies. Utilizing a quartz crystal microbalance with dissipation monitoring, we have been able to observe and quantitatively describe the antipolyelectrolyte behavior of the zwitterionic microgels. The oscillation frequency of the sensor proved to change reversibly according to the variations of the NaCl concentration, showing, in fact, the effect of the interaction between the salt and the opposite charges present in the microgel deposited on the sensor. Poly(ethersulfone) membranes, chosen as the model surface, when functionalized with zwitterionic microgel coatings, displayed protein-repelling property, stimulated by different transition temperatures, and showed even better performances at increasing NaCl concentration. These kinds of stimuli-responsive zwitterionic microgel can act as temperature-triggered drug delivery systems and as potential coating materials to prevent bioadhesion and biofouling as well.

Green Synthesis of Full-Color Fluorescent Carbon Nanoparticles from Eucalyptus Twigs for Sensing the Synthetic Food Colorant and Bioimaging.

Full-color fluorescent carbon nanoparticles (CNPs) are produced by a facile and green hydrothermal method followed by the differential washing technique. Eucalyptus twigs are used as a precursor to synthesize multiemissive light blue, blue, green, and red CNPs. Brilliant Blue FCF (BB) is a widely used synthetic food colorant, which is toxic for the human body, when consumed beyond the permitted limit. Herein, we demonstrate light blue CNPs as a sensor for selective and sensitive detection of BB via a fluorescence quenching mechanism with a limit of detection of 200 nM. Temperature-dependent fluorescence and 1H NMR studies confirmed the mechanism as combined dynamic and static quenching. To demonstrate the practical efficacy of the sensor, BB is effectively detected and estimated in selected food samples procured from the market. Moreover, the biocompatibility of light blue and blue CNPs is examined and confirmed by performing a cytotoxicity assay on MDA-MB-231 cell lines. Subsequently, the cellular imaging study is also carried out to explore the internalization process of the CNPs as a function of concentration. To the best of our knowledge, this is the first time that Eucalyptus twigs, a natural source of high abundance, are used as raw materials and valorized for sensing artificial food color and bioimaging purposes.

Impact of 5-formylcytosine on the melting kinetics of DNA by 1H NMR chemical exchange.

5-Formylcytosine (5fC) is a chemically edited, naturally occurring nucleobase which appears in the context of modified DNA strands. The understanding of the impact of 5fC on dsDNA physical properties is to date limited. In this work, we applied temperature-dependent 1H Chemical Exchange Saturation Transfer (CEST) NMR experiments to non-invasively and site-specifically measure the thermodynamic and kinetic influence of formylated cytosine nucleobase on the melting process involving dsDNA. Incorporation of 5fC within symmetrically positioned CpG sites destabilizes the whole dsDNA structure—as witnessed from the ∼2°C decrease in the melting temperature and 5–10 kJ mol−1 decrease in ΔG°—and affects the kinetic rates of association and dissociation. We observed an up to ∼5-fold enhancement of the dsDNA dissociation and an up to ∼3-fold reduction in ssDNA association rate constants, over multiple temperatures and for several proton reporters. Eyring and van’t Hoff analysis proved that the destabilization is not localized, instead all base-pairs are affected and the transition states resembles the single-stranded conformation. These results advance our knowledge about the role of 5fC as a semi-permanent epigenetic modification and assist in the understanding of its interactions with reader proteins.

Mixed-ligand platinum(II) complexes containing 2-(2′-pyridyl)phenyl and 8-quinolylphosphines: Synthesis and molecular structures in the crystals and in solution

A series of cyclometalated {2-(2′-pyridyl)phenyl}platinum(II) complexes having 8-quinolylphosphines, 8-(dimethylphosphino)quinoline (L1), 8-(diphenylphosphino)quinoline (L2), 2-methyl-8-(diphenylphosphino)quinoline (L3), and 2-phenyl-8-(diphenylphosphino)quinoline (L4), were prepared and their molecular structures and spectroscopic properties were investigated. The single-crystal X-ray analysis and the 31P{1H} NMR spectra of the products, [Pt(ppy)(Ln)](BF4 or OTf) {Cn; n = 1–4, ppy− = 2-(2′-pyridyl)phenyl, OTf− = trifluoromethanesulfonate} revealed the cis(P,C) configuration of the complex cations, although the square-planar PtII coordination geometry was considerably distorted. In particular, in the complexes C3 and C4 bearing sterically demanding 8-quinolylphosphines (L3 and L4), not only the tetrahedral distortion of the PtII coordination sphere but also a deviation of the PtII center from the planar chelate ring, i.e., an envelope-type distortion of the chelating quinolylphosphine coordination was observed. All complexes were stable in solution toward the addition of halide anions. However, a fluxional behavior of complexes C3 and C4, owing to the restricted inversion of the distorted coordination sphere, was observed in the temperature-dependent 1H NMR spectra.

Thermal perturbation of NMR properties in small polar and non-polar molecules

Water is an important constituent in an abundant number of chemical systems; however, its presence complicates the analysis of in situ1H MAS NMR investigations due to water’s ease of solidification and vaporization, the large changes in mobility, affinity for hydrogen bonding interactions, etc., that are reflected by dramatic changes in temperature-dependent chemical shielding. To understand the evolution of the signatures of water and other small molecules in complex environments, this work explores the thermally-perturbed NMR properties of water in detail by in situ MAS NMR over a wide temperature range. Our results substantially extend the previously published temperature-dependent 1H and 17O chemical shifts, linewidths, and spin-lattice relaxation times over a much wider range of temperatures and with significantly enhanced thermal resolution. The following major results are obtained: Hydrogen bonding is clearly shown to weaken at elevated temperatures in both 1H and 17O spectra, reflected by an increase in chemical shielding. At low temperatures, transient tetrahedral domains of H-bonding networks are evidenced and the observation of the transition between solid ice and liquid is made with quantitative considerations to the phase change. The 1H chemical shift properties in other small polar and non-polar molecules have also been described over a range of temperatures, showing the dramatic effect hydrogen bonding perturbation on polar species. Gas phase species are observed and chemical exchange between gas and liquid phases is shown to play an important role on the observed NMR shifts. The results disclosed herein lay the foundation for a clear interpretation of complex systems during the increasingly popular in situ NMR characterization at elevated temperatures and pressures for studying chemical systems.

A study on the synthesis, characterization, structural optimization, and conformational behaviors of bromo-substituted pyromelliticdiimide-based [2+2] macrocycle as structural units of covalently linked molecular tubes

Synthesis and structural, photo physical, and conformational behaviors at variable temperature and structural optimization of the pyromelliticdiimide-based bromo-substituted [2 + 2] macrocycles are described. Cyclization of the diamine (3) with dianhydride (4) in THF, followed by dehydration of the resultant amic acids resulted in the isolation of the bromo-substituted [2 + 2] macrocycle 1 (4.5%). The dynamic temperature-dependent 1H NMR spectra and MO calculations revealed the presence of two possible conformers for the [2 + 2] macrocycle 1. The UV/Vis spectrum of 1 reveals the presence of a weak intramolecular CT interaction of electron-withdrawing pyromelliticdiimide moiety with the electron-donating hexyloxy-substituted xylyl moiety. The cyclic voltammetric measurement shows two two-electron reversible reduction processes.

Influence of Glycoluril Molecular Clip Isomerization on the Mechanisms of Resorcinol Molecule Complexation

Supramolecular motifs showing chemoresponsive properties toward organic molecules are sought after. Their selectivity, however, may depend even on a small structural change. Here, we demonstrate the influence of isomerization of glycoluril molecular clips, equipped with N-(4-methoxyphenyl)isonicotinamide sidewalls, on the complexation of resorcinol. Concentration- and temperature-dependent 1H NMR and 1H–1H ROESY NMR experiments along with theoretical studies were employed to determine the detailed mechanisms and thermodynamic parameters of complexation for both isomers with resorcinol. This study shows that clip 1, equipped with N-(4-methoxyphenyl)isonicotinamide moieties oppositely directed along the glycoluril frame, is able to associate one resorcinol molecule within its cleft according to the “inner” mechanism with the equilibrium constant, K283K = 2340 M–1. Within the clip cleft, resorcinol forms hydrogen bonds via OH groups with oxygen atoms of clip’s urea moieties and interacts with clip aromatic sidewalls via π–π stacking. Clip 2, the isomer whose N-(4-methoxyphenyl)isonicotinamide moieties are oriented in the same direction along the glycoluril core, possesses two binding sites and complexes resorcinol according to 1:2 stoichiometry. One of the binding sites is located in the clip cleft analogous to clip 1, whereas the second one is created by the mutual arrangement of pyridinyl moieties. The distance between nitrogen groups of individual pyridine moieties matches the distance of resorcinol hydroxyl groups facilitating the formation of two hydrogen bonds according to the “outer” mechanism. Both mechanisms are spontaneous (ΔG11 and ΔG12 < 0); however, the association constant differs, that is, K11 = 2520 M–1 and K12 = 650 M–1 at 283 K. Both mechanisms are exothermic; however, the “outer” mechanism is more sensitive to the increase of temperature, as ΔH11 = −8.9 kcal/mol and ΔH12 = −19.8 kcal/mol. Clip 2 is a first unique example of the glycoluril clip, which is able to complex two resorcinol molecules, as generally, glycoluril clips interact with dihydroxyaromatics according to 1:1 stoichiometry.

Non-conventional low-molecular-weight organogelators with superhydrophobicity based on fluorescent β-diketone-boron difluorides

A series of β-diketone-boron difluoride derivatives bearing different methyl-substituted phenyl groups were designed and synthesized, and two of these boron-difluorides could form stable organogels in non-polar solvents, demonstrating that the methyl substituents have a significant effect on their gelation ability. Through temperature-dependent 1H NMR and photophysical properties analysis, we deemed that intermolecular non-covalent interactions facilitate the one-dimensional packing. Moreover, superhydrophobic surfaces, characterized by water contact angles around 150° could be obtained by means of the gelation of these boron-difluoride dyes. Thus, our work provided a unique example for designing non-conventional organogelators with superhydrophobic surfaces by introducing methyl-substituted phenyl groups into β-diketone-boron difluoride skeleton.

Optoelectronic properties and aggregation effects on the performance of planar versus contorted pyrene-cored perylenediimide dimers for organic solar cells

In this work, we present a new strategy to develop small molecules based on perylenediimde (PDI) with fused and contorted conjugated backbones as electron acceptors for fullerene-free organic solar cells. The two new electron acceptors, 27-Py-PDI and 49-Py-PDI, containing binary PDI units fused with pyrene at different positions were structurally isomers, which were investigated systematically. Theoretical calculations indicated that the two positional isomers exhibit distinct molecular geometries (planar for 27-Py-PDIvs contorted for 49-Py-PDI), which lead to huge differences on their synthetic methods, aggregation effects and their optoelectronic properties. The effects of structural isomerism on the molecular geometry, optical spectra, energy levels, charge carrier mobility and the morphology discrepancies as well as the corresponding photovoltaic performance were fully investigated. Temperature-dependent 1H NMR and the film UV–vis spectroscopy were used to study the molecular aggregation behaviors. Calculations of nuclear independent chemical shifts (NICS) indicate significant difference of the aromaticity between the isomers. Blended with donor materials of PTB7-Th to fabricate the inverted solar cells, an encouraging PCE of 4.53% along with an impressive open-circuit voltage (VOC) of 1.0 V (higher than the other acceptors based on PDIs and the PC71BM) were achieved by using 49-Py-PDI, which were superior to those of its isomer 27-Py-PDI (2.51%). The work suggests that introducing rigid and contorted features into fully fused acceptors based on PDI motifs can enhance the interface energy gap (ΔEDA), extend the π-delocalization and decrease the conformational disorder resulting into improved VOC without sacrificing JSC in OPV devices. This design strategy by introducing rigid and steric hindrance to increase intermolecular strain to construct fully ring fused contorted acceptors is an effective approach for the development of novel NFAs.

Comprehensive Picture of Water Dynamics in Nafion Membranes at Different Levels of Hydration.

1H NMR spectroscopy is employed to study the long-range (diffusion) and short-range (relaxation) motions of water in the hydrophilic channels of Nafion at different stages of hydration, λwater. From Bloembergen, Purcell, and Pound analysis of the temperature-dependent 1H spin-lattice relaxation rates, the coexistence of two motional modes for λwater < 9 was observed, which can be attributed to the nonfreezing behavior of water molecules. At higher hydration levels, a clear transition between two different motional modes was detected associated with the freezing of bulk water. The hydration-level-dependent diffusion 1H NMR studies showed a steep increase in diffusion coefficients at 6 ≤ λwater ≤ 9 followed by a linear increase with the increasing hydration level (λwater ≥ 12). Taken together the correlation of long- and short-range motion studies allowed us to establish a comprehensive picture of the hydration shell formation for the sulfonic acid groups in Nafion dependent on λwater that can be divided into three characteristic regions. These include the formation of the first hydration shell at λwater ≈ 3 (region I), the second hydration shell at λwater ≈ 8 (region II), and finally (iii) the presence of bulk water above λwater ≥ 10 (region III).

Hybrid Poly(hydroxy urethane)s: Folded-Sheet Morphology and Thermoreversible Adhesion.

Hybrid poly(hydroxy urethane)s (PHUs) are synthesized by copolymerizing aromatic/alicyclic cyclic carbonates with a polyether amine via addition polymerization. They result into polymers with an average molecular weight of 10 kDa and exhibit solubility in common organic solvents. The hybrid PHUs display Tg up to 18 °C. PHUs are enriched with multiple H-bonded interactions and they are assessed using temperature-dependent 1H NMR and Fourier-transform infrared studies. PHUs possess folded-sheet morphology with nanogap between folds and nanowidth between chains. The secondary interactions bestow thermoreversible property to PHUs, and they display good adhesion to both polar (Al–Al) and nonpolar (HDPE–HDPE) substrates. Hybrid PHUs show improved optical transparency compared to homo PHUs. The PHUs are thermally stable up to 250 °C.

Investigating the Internal Processes of Thermo-Electrochemical Cells Using in-Situ Magnetic Resonance Imaging

Thermo-electrochemical cells are emerging as a promising and efficient method to convert waste heat to electricity. In addition to developing novel redox electrolyte materials to increase the energy densities, it is crucial for future developments to understand the internal chemical and thermodynamical processes happening inside the thermo-electrochemical cell while it is under operating conditions. Although the temperature and concentration distributions between the electrodes and the variations of the convection currents with cell orientation have been modelled mathematically, it has been a challenge to study these internal processes using experimental techniques. Magnetic resonance imaging (MRI) is a non-invasive and well-established diagnosis technique in medical research to investigate physiology, but it also has the capability to study spatial properties of materials, chemical and thermodynamic processes in energy storage devices using different image contrast options including spin density, relaxation time and velocity [1]. The goals of this study are to develop an MRI method to study the internal chemical and thermodynamic processes within a functioning thermo-electrochemical cell, and understanding how these are affected by the electrolyte, the cell geometry and the orientation of the thermal gradient. A cobalt redox couple based electrolyte, which has been shown to be a promising candidate for thermo-electrochemical cells [2], was used for the in-situ experiments inside specialised cells custom built for MRI experiments, and temperature and concentration dependent 1H nuclear magnetic resonance spin-lattice relaxation time (T1) measurements were used to interpret the 1H T1 weighted MRI images of the working cells.