Pub Date : 2025-05-14DOI: 10.1016/j.jmro.2025.100203
Kelsey Anne Marr, Alexej Jerschow
Radiation damping is a well-known phenomenon in the context of NMR spectroscopy. Several strategies exist for minimizing the effects of radiation damping, which have mostly been focused on limiting the effects of one resonance (frequently the water resonance). When samples with many resonances are examined at high concentration, such approaches often cannot be used. One category of systems where the broadband nature of radiation damping leads to complications are deep eutectic solvents (DESs). DESs are considered innovative solvent systems that have several advantages such as tunability and environmental friendliness, with important applications ranging from catalysis to drug delivery. It is of interest to examine the intermolecular effects via NMR spectroscopy in these systems. Here we show that broadband radiation effects are very strong in these systems and identify simple strategies specifically for 2D NOESY NMR spectroscopy to regain the ability to quantify intermolecular interactions in these systems.
{"title":"Avoiding broadband radiation damping effects in NOESY spectra","authors":"Kelsey Anne Marr, Alexej Jerschow","doi":"10.1016/j.jmro.2025.100203","DOIUrl":"10.1016/j.jmro.2025.100203","url":null,"abstract":"<div><div>Radiation damping is a well-known phenomenon in the context of NMR spectroscopy. Several strategies exist for minimizing the effects of radiation damping, which have mostly been focused on limiting the effects of one resonance (frequently the water resonance). When samples with many resonances are examined at high concentration, such approaches often cannot be used. One category of systems where the broadband nature of radiation damping leads to complications are deep eutectic solvents (DESs). DESs are considered innovative solvent systems that have several advantages such as tunability and environmental friendliness, with important applications ranging from catalysis to drug delivery. It is of interest to examine the intermolecular effects via NMR spectroscopy in these systems. Here we show that broadband radiation effects are very strong in these systems and identify simple strategies specifically for 2D NOESY NMR spectroscopy to regain the ability to quantify intermolecular interactions in these systems.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100203"},"PeriodicalIF":2.624,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-21DOI: 10.1016/j.jmro.2025.100200
Ligang Xu , Yuqi Li , Yongchao shi , Yachao Yan , Wengui Yu , Huajie Luo , Jipeng Fu , Haiyan Zheng , Mingxue Tang
The rise of the new energy market has driven the rapid development of solid-state batteries (SSBs). Polymer electrolytes, due to their excellent interfacial compatibility and high safety, have brought new opportunities to SSBs. We report a polymer side-chain design strategy that combines ionic liquids and low-molecular-weight ether-based molecules into a copolymer electrolyte (CPE). Using nuclear magnetic resonance (NMR) techniques, we investigated the spatial distribution of lithium ions (Li+) and the correlations between anions of different conformations in the CPE. This study found that the introduced ionic liquids and high-freedom ether groups enable rapid ion migration, resulting in an ion conductivity of 1.44 × 10–4 S cm-1 at 25 °C. The dual lithium symmetric battery based on CPE can cycle more than1000 h at a current density of 0.3 mA cm-2, while the LFP|CPE|Li full battery presents high retention after 120 cycles even at ultra-high loading (12.9 mg cm-2) and a high current density of 1 C.
新能源市场的兴起带动了固态电池的快速发展。聚合物电解质以其良好的界面相容性和较高的安全性为固态固体材料的研究带来了新的机遇。我们报告了一种聚合物侧链设计策略，将离子液体和低分子量醚基分子结合成共聚物电解质（CPE）。利用核磁共振（NMR）技术，研究了锂离子（Li+）在CPE中的空间分布以及不同构象阴离子之间的相关性。本研究发现，引入的离子液体和高自由度醚基团使离子快速迁移，在25°C时离子电导率为1.44 × 10-4 S cm-1。基于CPE的双锂对称电池在0.3 mA cm-2的电流密度下可以循环1000 h以上，而LFP|CPE|Li全电池在超高负载（12.9 mg cm-2）和1 C的高电流密度下也能在120次循环后保持较高的电量。
{"title":"Understanding the correlation between ion transport and side chains in polymer electrolyte","authors":"Ligang Xu , Yuqi Li , Yongchao shi , Yachao Yan , Wengui Yu , Huajie Luo , Jipeng Fu , Haiyan Zheng , Mingxue Tang","doi":"10.1016/j.jmro.2025.100200","DOIUrl":"10.1016/j.jmro.2025.100200","url":null,"abstract":"<div><div>The rise of the new energy market has driven the rapid development of solid-state batteries (SSBs). Polymer electrolytes, due to their excellent interfacial compatibility and high safety, have brought new opportunities to SSBs. We report a polymer side-chain design strategy that combines ionic liquids and low-molecular-weight ether-based molecules into a copolymer electrolyte (CPE). Using nuclear magnetic resonance (NMR) techniques, we investigated the spatial distribution of lithium ions (Li<sup>+</sup>) and the correlations between anions of different conformations in the CPE. This study found that the introduced ionic liquids and high-freedom ether groups enable rapid ion migration, resulting in an ion conductivity of 1.44 × 10<sup>–4</sup> S cm<sup>-1</sup> at 25 °C. The dual lithium symmetric battery based on CPE can cycle more than1000 h at a current density of 0.3 mA cm<sup>-2</sup>, while the LFP|CPE|Li full battery presents high retention after 120 cycles even at ultra-high loading (12.9 mg cm<sup>-2</sup>) and a high current density of 1 C.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100200"},"PeriodicalIF":2.624,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-16DOI: 10.1016/j.jmro.2025.100199
Qian Li , Junfeng Xiang
With the rapid advancement of NMR magnet and probe technology, high-field NMR spectrometers equipped with high-resolution and high-sensitivity probes will find broader applications in the field of chemical research. The spectral resolution of NMR increases proportionally with the magnetic field strength (B0). Higher magnetic fields of NMR increase the separation between different resonant frequencies of nuclei, leading to better spectral resolution. Besides spectral resolution, the signal-to-noise ratio (SNR) is proportional to the magnetic field strength raised to the power of three-halves. Advancements in probe technology over the past few decades have led to the widespread adoption of probeheads equipped with coils and preamplifiers that are cryogenically cooled by cold helium or nitrogen. This significantly reduces system noise, thereby improving SNR in detection. A series of typical applications of high-field nuclear magnetic resonance (NMR) in chemical research has been introduced. By utilizing the broadband direct observe cryoprobe (DOCP), a wide range of nuclei can be detected with high sensitivity, enabling the efficient characterization of numerous chemical systems at natural abundance, without the need for time-consuming and costly isotope labeling processes. High-field, high-sensitivity, and high-resolution NMR techniques provide promising tools that are likely to play an increasingly important role in future chemical investigations.
{"title":"Applications of high-field nuclear magnetic resonance (NMR) in chemical research","authors":"Qian Li , Junfeng Xiang","doi":"10.1016/j.jmro.2025.100199","DOIUrl":"10.1016/j.jmro.2025.100199","url":null,"abstract":"<div><div>With the rapid advancement of NMR magnet and probe technology, high-field NMR spectrometers equipped with high-resolution and high-sensitivity probes will find broader applications in the field of chemical research. The spectral resolution of NMR increases proportionally with the magnetic field strength (B0). Higher magnetic fields of NMR increase the separation between different resonant frequencies of nuclei, leading to better spectral resolution. Besides spectral resolution, the signal-to-noise ratio (SNR) is proportional to the magnetic field strength raised to the power of three-halves. Advancements in probe technology over the past few decades have led to the widespread adoption of probeheads equipped with coils and preamplifiers that are cryogenically cooled by cold helium or nitrogen. This significantly reduces system noise, thereby improving SNR in detection. A series of typical applications of high-field nuclear magnetic resonance (NMR) in chemical research has been introduced. By utilizing the broadband direct observe cryoprobe (DOCP), a wide range of nuclei can be detected with high sensitivity, enabling the efficient characterization of numerous chemical systems at natural abundance, without the need for time-consuming and costly isotope labeling processes. High-field, high-sensitivity, and high-resolution NMR techniques provide promising tools that are likely to play an increasingly important role in future chemical investigations.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100199"},"PeriodicalIF":2.624,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-03DOI: 10.1016/j.jmro.2025.100196
Uršulė Tarvydytė , Vidmantas Kalendra , Gediminas Usevičius , James O’Sullivan , Adam Brookfield , Alice M. Bowen , Jūras Banys , John J.L. Morton , Mantas Šimėnas
We present a new design of an X-band EPR cryoprobe based on a fast microwave switch and a cryogenic low-noise microwave amplifier that are placed close to the sample in the same cryostat. The probehead supports high-power (100 W) pulsed EPR experiments and is compatible with standard EPR resonators and samples. In contrast to the directional coupler design of the EPR cryoprobe reported previously, the fast microwave switch fully isolates the microwave amplifier from input thermal noise without microwave power suppression allowing us to approach the sensitivity limit of cryoprobes for pulsed EPR experiments. We benchmark the performance of our cryoprobe setup against a standard commercial EPR instrument revealing a significant sensitivity improvement, which reduces the measurement time by a factor of about at 6 K sample temperature. We also show that the sensitivity of our new X-band cryoprobe design matches that of a standard Q-band setup for double electron–electron resonance experiments.
{"title":"Pushing the sensitivity boundaries of X-band EPR cryoprobe using a fast microwave switch","authors":"Uršulė Tarvydytė , Vidmantas Kalendra , Gediminas Usevičius , James O’Sullivan , Adam Brookfield , Alice M. Bowen , Jūras Banys , John J.L. Morton , Mantas Šimėnas","doi":"10.1016/j.jmro.2025.100196","DOIUrl":"10.1016/j.jmro.2025.100196","url":null,"abstract":"<div><div>We present a new design of an X-band EPR cryoprobe based on a fast microwave switch and a cryogenic low-noise microwave amplifier that are placed close to the sample in the same cryostat. The probehead supports high-power (100 W) pulsed EPR experiments and is compatible with standard EPR resonators and samples. In contrast to the directional coupler design of the EPR cryoprobe reported previously, the fast microwave switch fully isolates the microwave amplifier from input thermal noise without microwave power suppression allowing us to approach the sensitivity limit of cryoprobes for pulsed EPR experiments. We benchmark the performance of our cryoprobe setup against a standard commercial EPR instrument revealing a significant sensitivity improvement, which reduces the measurement time by a factor of about <span><math><mrow><mn>250</mn><mo>×</mo></mrow></math></span> at 6 K sample temperature. We also show that the sensitivity of our new X-band cryoprobe design matches that of a standard Q-band setup for double electron–electron resonance experiments.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100196"},"PeriodicalIF":2.624,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-02DOI: 10.1016/j.jmro.2025.100198
Nick J. Hol , Ismail Myouri , Claire Chassagne , Leo Pel
This study presents a method to determine surface relaxivity in soft sediments by combining one-dimensional Nuclear Magnetic Resonance (NMR) imaging with particle size and shape estimates. In order to determine the surface relaxivity up to now often methods like Mercury Intrusion Porosimetry or Brunauer–Emmett–Teller (BET) are used which where drying steps are involved which can alter material properties during analysis, particularly in highly deformable materials, making these techniques unreliable for soft soils. By combining NMR relaxometry and estimates of particle sizes and shapes of a soft soil, this new approach provides accurate, non-invasive surface relaxivity measurements. This method is demonstrated on kaolinite, glass beads, and natural soils, showing that this method supports detailed assessment of pore size distributions in soft sediments, benefiting geotechnical and environmental research where soil stability is critical.
{"title":"Determination of the surface relaxivity of soft sediment using particle size and shape","authors":"Nick J. Hol , Ismail Myouri , Claire Chassagne , Leo Pel","doi":"10.1016/j.jmro.2025.100198","DOIUrl":"10.1016/j.jmro.2025.100198","url":null,"abstract":"<div><div>This study presents a method to determine surface relaxivity in soft sediments by combining one-dimensional Nuclear Magnetic Resonance (NMR) imaging with particle size and shape estimates. In order to determine the surface relaxivity up to now often methods like Mercury Intrusion Porosimetry or Brunauer–Emmett–Teller (BET) are used which where drying steps are involved which can alter material properties during analysis, particularly in highly deformable materials, making these techniques unreliable for soft soils. By combining NMR relaxometry and estimates of particle sizes and shapes of a soft soil, this new approach provides accurate, non-invasive surface relaxivity measurements. This method is demonstrated on kaolinite, glass beads, and natural soils, showing that this method supports detailed assessment of pore size distributions in soft sediments, benefiting geotechnical and environmental research where soil stability is critical.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100198"},"PeriodicalIF":2.624,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-28DOI: 10.1016/j.jmro.2025.100197
Yue Dou , Qing Wang , Hengxing Ji , Haiming Liu
The spatial dynamics of cations have a significant impact on the photodynamic behavior of excited states in high-performance hybrid organic-inorganic perovskites. Multinuclear (1H, 2H, and 14N) solid-state NMR (SSNMR) spectroscopy has traditionally been utilized to study the motion of methylammonium (MA) cations in methylammonium lead (II) halides MAPbX3 (X = I, Br, Cl). NMR methods based on spin-lattice relaxation or quadrupolar line shape analysis over a limited temperature range demonstrate rapid MA reorientation, but the cation dynamics in a wider temperature range covering phase transition of all major crystallographic phases is lacking. Due to its low sensitivity, 13C NMR is rarely used to assess MA dynamics in these perovskites. Herein, we adopte variable-temperature (VT) 13C MAS NMR at very high resolution and dipolar-coupled transverse relaxation analysis as a new tool for dynamical characterization without isotopic enrichment, and systematically investigated MA dynamics in MAPbX3 across phase transitions. This new approach enables retrieval of activation energy of MA reorientation and assessment of motion regimes. We propose a generalized “Camel model” that describes the common trend of cation dynamics for MAPbX3, suggesting possible complicated reorientation modes. Furthermore, we discover the evolution of multiple MA sites in orthorhombic MAPbCl3, consistent with X-ray crystallography, demonstrating its unique advantage in resolving and characterizing multi-cation dynamics. The VT 13C SSNMR effectively probes organic ion motions and phase transitions in hybrid perovskites, helpful for further elucidating the structure-property relationship in photovoltaic conversion mechanisms.
阳离子的空间动力学对高性能有机-无机杂化钙钛矿中激发态的光动力学行为有重要影响。多核（1H， 2H和14N）固态核磁共振（SSNMR）光谱传统上被用于研究甲基铵铅（II）卤化物MAPbX3 （X = I, Br, Cl）中甲基铵（MA）阳离子的运动。基于自旋晶格弛豫或四极线形分析的核磁共振方法在有限的温度范围内显示出快速的MA重定向，但缺乏涵盖所有主要晶体相相变的更宽温度范围内的阳离子动力学。由于其低灵敏度，13C核磁共振很少用于评估这些钙钛矿中的MA动力学。本文采用超高分辨率的变温13C MAS NMR和偶极耦合横向弛豫分析作为不富集同位素的动力学表征新工具，系统地研究了MAPbX3在不同相变中的MA动力学。这种新方法可以检索MA重新定向的激活能和评估运动状态。我们提出了一个广义的“骆驼模型”，描述了MAPbX3阳离子动力学的共同趋势，提出了可能的复杂重定向模式。此外，我们发现了正交MAPbCl3中多个MA位点的演化，与x射线晶体学一致，证明了其在解析和表征多阳离子动力学方面的独特优势。VT 13C SSNMR有效地探测了杂化钙钛矿中有机离子的运动和相变，有助于进一步阐明光伏转换机制中的结构-性能关系。
{"title":"Probing cation dynamics and phase transition in hybrid organic-inorganic perovskites by 13C solid-state NMR spectroscopy at very high resolution","authors":"Yue Dou , Qing Wang , Hengxing Ji , Haiming Liu","doi":"10.1016/j.jmro.2025.100197","DOIUrl":"10.1016/j.jmro.2025.100197","url":null,"abstract":"<div><div>The spatial dynamics of cations have a significant impact on the photodynamic behavior of excited states in high-performance hybrid organic-inorganic perovskites. Multinuclear (<sup>1</sup>H, <sup>2</sup>H, and <sup>14</sup>N) solid-state NMR (SSNMR) spectroscopy has traditionally been utilized to study the motion of methylammonium (MA) cations in methylammonium lead (II) halides MAPbX<sub>3</sub> (X = I, Br, Cl). NMR methods based on spin-lattice relaxation or quadrupolar line shape analysis over a limited temperature range demonstrate rapid MA reorientation, but the cation dynamics in a wider temperature range covering phase transition of all major crystallographic phases is lacking. Due to its low sensitivity, <sup>13</sup>C NMR is rarely used to assess MA dynamics in these perovskites. Herein, we adopte variable-temperature (VT) <sup>13</sup>C MAS NMR at very high resolution and dipolar-coupled transverse relaxation analysis as a new tool for dynamical characterization without isotopic enrichment, and systematically investigated MA dynamics in MAPbX<sub>3</sub> across phase transitions. This new approach enables retrieval of activation energy of MA reorientation and assessment of motion regimes. We propose a generalized “Camel model” that describes the common trend of cation dynamics for MAPbX<sub>3</sub>, suggesting possible complicated reorientation modes. Furthermore, we discover the evolution of multiple MA sites in orthorhombic MAPbCl<sub>3</sub>, consistent with X-ray crystallography, demonstrating its unique advantage in resolving and characterizing multi-cation dynamics. The VT <sup>13</sup>C SSNMR effectively probes organic ion motions and phase transitions in hybrid perovskites, helpful for further elucidating the structure-property relationship in photovoltaic conversion mechanisms.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100197"},"PeriodicalIF":2.624,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-12DOI: 10.1016/j.jmro.2025.100193
W.Th. Wenckebach
Paramagnetic relaxation in solids is a vast subject, about as vast as the range of manifestations of electron spin in matter. It is a complex subject as well: it is the interface between paramagnetic centres – be it transition metal ions, radicals or defects – and quantized vibrations: phonons. So it requires an understanding of both these phonons and those paramagnetic centres. Moreover, contrary to the case of integer spin, for half-integer spin the coupling between electron spins and phonons is indirect. Two interactions are needed, the spin–orbit interaction between the spin and the orbits of the paramagnetic centre and the orbit–phonon interaction between the latter and the phonons.
The present article is an effort to navigate the theory of this extensive subject for spin and aims to derive the main properties of the two most important mechanisms: direct and red Raman relaxation. It tries to do so from first principles, that is, it includes a generalized, but fundamental description of the vibrational states, the orbital and spin states on the one hand, and the orbit–phonon and spin–orbit interaction on the other. Based on these descriptions it derives the transition matrix elements responsible for paramagnetic relaxation, following the original approach of Van Vleck for paramagnetic centres with spin , a relatively weak spin–orbit interaction and embedded in an insulating, diamagnetic solid. Subsequently phonon statistics are included to derive the paramagnetic relaxation rates. No effort is done to review the vast body of experimental work on the subject.
{"title":"Paramagnetic relaxation: Direct and Raman relaxation of spin S=12","authors":"W.Th. Wenckebach","doi":"10.1016/j.jmro.2025.100193","DOIUrl":"10.1016/j.jmro.2025.100193","url":null,"abstract":"<div><div>Paramagnetic relaxation in solids is a vast subject, about as vast as the range of manifestations of electron spin in matter. It is a complex subject as well: it is the interface between paramagnetic centres – be it transition metal ions, radicals or defects – and quantized vibrations: phonons. So it requires an understanding of both these phonons and those paramagnetic centres. Moreover, contrary to the case of integer spin, for half-integer spin the coupling between electron spins and phonons is indirect. Two interactions are needed, the spin–orbit interaction between the spin and the orbits of the paramagnetic centre and the orbit–phonon interaction between the latter and the phonons.</div><div>The present article is an effort to navigate the theory of this extensive subject for spin <span><math><mrow><mi>S</mi><mo>=</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></math></span> and aims to derive the main properties of the two most important mechanisms: direct and red Raman relaxation. It tries to do so from first principles, that is, it includes a generalized, but fundamental description of the vibrational states, the orbital and spin states on the one hand, and the orbit–phonon and spin–orbit interaction on the other. Based on these descriptions it derives the transition matrix elements responsible for paramagnetic relaxation, following the original approach of Van Vleck for paramagnetic centres with spin <span><math><mrow><mi>S</mi><mo>=</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></math></span>, a relatively weak spin–orbit interaction and embedded in an insulating, diamagnetic solid. Subsequently phonon statistics are included to derive the paramagnetic relaxation rates. No effort is done to review the vast body of experimental work on the subject.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100193"},"PeriodicalIF":2.624,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-10DOI: 10.1016/j.jmro.2025.100195
Joris Mandral , Johnnie Phuong , Jonathan Farjon , Patrick Giraudeau , Kerstin Münnemann , Jean-Nicolas Dumez
Benchtop Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful analytical technique for the monitoring of reactions and processes due to its accessibility and lower cost compared to high-field NMR. However, benchtop NMR spectroscopy often suffers from limited sensitivity and resolution. In this work, we have combined ultrafast (UF) 2D NMR with Overhauser Dynamic Nuclear Polarization (ODNP) to tackle both problems. Compared to thermally polarized 1D NMR, UF 2D NMR provides improved spectral resolution in a single scan whereas ODNP boosts the NMR sensitivity. To demonstrate the possibility of combining UF 2D NMR with ODNP for process monitoring applications, experiments were carried out at different flow conditions. Our results show that ODNP at least compensated for the losses in sensitivity of UF 2D NMR that are normally induced by high flow velocities. Moreover, under certain flow conditions, ODNP brings additional sensitivity to UF 2D NMR spectra, with SNR increased by a factor of >3 compared to thermal equilibrium acquisitions. The methods developed in this article are expected to be beneficial for more informative and sensitive acquisitions in the context of process monitoring.
{"title":"Ultrafast 2D benchtop NMR spectroscopy enhanced by flow Overhauser dynamic nuclear polarization","authors":"Joris Mandral , Johnnie Phuong , Jonathan Farjon , Patrick Giraudeau , Kerstin Münnemann , Jean-Nicolas Dumez","doi":"10.1016/j.jmro.2025.100195","DOIUrl":"10.1016/j.jmro.2025.100195","url":null,"abstract":"<div><div>Benchtop Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful analytical technique for the monitoring of reactions and processes due to its accessibility and lower cost compared to high-field NMR. However, benchtop NMR spectroscopy often suffers from limited sensitivity and resolution. In this work, we have combined ultrafast (UF) 2D NMR with Overhauser Dynamic Nuclear Polarization (ODNP) to tackle both problems. Compared to thermally polarized 1D NMR, UF 2D NMR provides improved spectral resolution in a single scan whereas ODNP boosts the NMR sensitivity. To demonstrate the possibility of combining UF 2D NMR with ODNP for process monitoring applications, experiments were carried out at different flow conditions. Our results show that ODNP at least compensated for the losses in sensitivity of UF 2D NMR that are normally induced by high flow velocities. Moreover, under certain flow conditions, ODNP brings additional sensitivity to UF 2D NMR spectra, with SNR increased by a factor of >3 compared to thermal equilibrium acquisitions. The methods developed in this article are expected to be beneficial for more informative and sensitive acquisitions in the context of process monitoring.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100195"},"PeriodicalIF":2.624,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143641918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1016/j.jmro.2025.100192
Bintian Lu , Weiyu Wang , Shuangqin Zeng , Xiuzhi Gao , Jun Xu , Feng Deng
Selective butadiene hydrogenation to butene is a crucial process in the petrochemical industry, however, a comprehensive understanding of the underlying structure-activity relationships remains elusive. This study explores the influence of supported metal nanoparticle proximity on butadiene hydrogenation using parahydrogen-induced polarization NMR spectroscopy. A sol-immobilization method was employed to systematically control the spacing between PdAu nanoparticles on Pd-Au/TiO2 catalysts, while preserving their overall physicochemical properties. Experimental results demonstrate that denser PdAu nanoparticle arrangements lead to enhanced catalytic activity. This improved activity is coupled with accelerated isomerization of the semi-hydrogenated butene and over-hydrogenation to butane, facilitated by enhanced butene adsorption and subsequent conversion. Furthermore, increasing the hydrogen content significantly boosts butadiene conversion and butane formation, while having a less impact on butene isomerization. The addition of an inert support material, altering the spatial distribution of catalyst particles, positively affects both catalytic activity and butene selectivity. These findings highlight the critical role of nanoparticle proximity in controlling reaction pathways in butadiene hydrogenation.
{"title":"Probing nanoparticle proximity effects on selective butadiene hydrogenation over Pd-Au/TiO2 with parahydrogen-induced polarization NMR","authors":"Bintian Lu , Weiyu Wang , Shuangqin Zeng , Xiuzhi Gao , Jun Xu , Feng Deng","doi":"10.1016/j.jmro.2025.100192","DOIUrl":"10.1016/j.jmro.2025.100192","url":null,"abstract":"<div><div>Selective butadiene hydrogenation to butene is a crucial process in the petrochemical industry, however, a comprehensive understanding of the underlying structure-activity relationships remains elusive. This study explores the influence of supported metal nanoparticle proximity on butadiene hydrogenation using parahydrogen-induced polarization NMR spectroscopy. A sol-immobilization method was employed to systematically control the spacing between PdAu nanoparticles on Pd-Au/TiO<sub>2</sub> catalysts, while preserving their overall physicochemical properties. Experimental results demonstrate that denser PdAu nanoparticle arrangements lead to enhanced catalytic activity. This improved activity is coupled with accelerated isomerization of the semi-hydrogenated butene and over-hydrogenation to butane, facilitated by enhanced butene adsorption and subsequent conversion. Furthermore, increasing the hydrogen content significantly boosts butadiene conversion and butane formation, while having a less impact on butene isomerization. The addition of an inert support material, altering the spatial distribution of catalyst particles, positively affects both catalytic activity and butene selectivity. These findings highlight the critical role of nanoparticle proximity in controlling reaction pathways in butadiene hydrogenation.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100192"},"PeriodicalIF":2.624,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1016/j.jmro.2025.100194
Kirill Sheberstov , Erik Van Dyke , Jingyan Xu , Raphael Kircher , Liubov Chuchkova , Yinan Hu , Sulaiman Alvi , Dmitry Budker , Danila A. Barskiy
Optimization of nuclear spin hyperpolarization experiments often require varying one system parameter at a time (or several parameters in a nontrivial manner) as well as multiple repetitions of signal measurements. Use of automated robotic systems can significantly streamline this optimization process, accelerating data acquisition and improving reproducibility in the long term. In this work we show an exemplary system built on open-source components and demonstrate several benchtop and ultralow-field NMR experiments employing photo-CIDNP and SABRE-derived hyperpolarization. This work illustrates that open-source platforms employing benchtop NMR and robotic systems built in a modular manner with remote operation allow the implementation of various unconventional experiments in a reproducible manner.
{"title":"Robotic arms for hyperpolarization-enhanced NMR","authors":"Kirill Sheberstov , Erik Van Dyke , Jingyan Xu , Raphael Kircher , Liubov Chuchkova , Yinan Hu , Sulaiman Alvi , Dmitry Budker , Danila A. Barskiy","doi":"10.1016/j.jmro.2025.100194","DOIUrl":"10.1016/j.jmro.2025.100194","url":null,"abstract":"<div><div>Optimization of nuclear spin hyperpolarization experiments often require varying one system parameter at a time (or several parameters in a nontrivial manner) as well as multiple repetitions of signal measurements. Use of automated robotic systems can significantly streamline this optimization process, accelerating data acquisition and improving reproducibility in the long term. In this work we show an exemplary system built on open-source components and demonstrate several benchtop and ultralow-field NMR experiments employing photo-CIDNP and SABRE-derived hyperpolarization. This work illustrates that open-source platforms employing benchtop NMR and robotic systems built in a modular manner with remote operation allow the implementation of various unconventional experiments in a reproducible manner.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100194"},"PeriodicalIF":2.624,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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