Article
Chemistry, Multidisciplinary
David S. Rivera Rocabado, Tomohiro G. Noguchi, Shio Hayashi, Nobutaka Maeda, Miho Yamauchi, Takayoshi Ishimoto
Summary: Research uncovered the adsorption states of N-2 and H-2 on MgO-supported Ru nanoparticles under conditions close to ammonia synthesis, showing that N-2 molecules migrated from top sites to bridge sites, horizontally adsorbed N-2 molecules were activated, and H-2 molecules rapidly dissociated.
Article
Energy & Fuels
Shuangshuang Zuo, Guoyan Chen, Anchao Zhang, Haoxin Deng, Xiaoping Wen, Fahui Wang
Summary: Ammonia, as a clean energy source, has potential applications in gas turbine power production. The presence of N2 at high temperatures affects the combustion characteristics of ammonia. This study investigated the combustion characteristics of NH3/H2/air flame under different N2 dilution ratios and equivalent ratios using a constant-pressure spherical flame method. The experimental results showed that N2 dilution decreased the laminar burning velocities of the mixture and inhibited the flame propagation. The presence of diluent N2 reduced the major branching reactions and enhanced the inhibition of radical pool and primitive reactions.
Article
Engineering, Environmental
Yan Xie, Tao Zheng, Yu-Jie Zhu, Jin-Rong Zhong, Jing-Chun Feng, Chang-Yu Sun, Guang-Jin Chen
Summary: This study investigated the effects of H-2 and N-2 gases on the growth of CO2 hydrate films using microscopy and Raman spectroscopy. The results showed that H-2 gas significantly influenced the morphology and compactness of CO2 hydrate films, while N-2 gas had a similar effect but led to adaptive changes in film growth.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Physics, Fluids & Plasmas
Xin Yang, Elijah Jans, Caleb Richards, Sai Raskar, Dirk van den Bekerom, Kai Wu, Igor Adamovich
Summary: This study examines the role of the electronic excited states of N-2(A(3)Sigma(+)(u)) molecules in the dissociation of N2 in plasmas. It is found that energy pooling in collisions between N-2(A(3)Sigma(+)(u)) molecules plays a major role in N2 dissociation. Additionally, the rapid quenching by H atoms leads to a significant reduction in N-2(A(3)Sigma(+)(u)) populations and the rate of N atom generation.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Samiul Hasan, Mohi Uddin Jewel, Stavros G. Karakalos, Mikhail Gaevski, Iftikhar Ahmad
Summary: A comparative spectroscopic study was conducted on thin films of epitaxial aluminum nitride (AlN) grown in different gas environments. The study found that AlN films grown in a N-2 environment have less stress but higher carbon and oxygen impurity content compared to films grown in a H-2 environment.
Article
Chemistry, Physical
Jingyan Wang, Yuntao Liang, Zhenzhen Zhao
Summary: In this study, the explosion behaviors of H-2-LPG-air mixtures were experimentally investigated under the action of N-2 and CO2. The addition of N-2 and CO2 reduces the maximum explosion pressure and maximum rate of pressure rise, and postpones the arrival of explosion peak. CO2 demonstrates a better inhibitory effect on the H-2-LPG-air mixture explosion compared to N-2. The addition of CO2 not only inhibits explosion by its physical properties, but also participates in chemical reactions, consuming free radicals and reducing their concentration.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Physics, Multidisciplinary
Shengzhe Pan, Zhaohan Zhang, Liang Xu, Wenbin Zhang, Peifen Lu, Qinying Ji, Kang Lin, Lianrong Zhou, Chenxu Lu, Hongcheng Ni, Camilo Ruiz, Kiyoshi Ueda, Feng He, Jian Wu
Summary: We show that dissociative ionization of H2 can be manipulated by a polarization-skewed laser pulse. The leading and falling edges of the pulse trigger parallel and perpendicular transitions of stretching H2 molecules, resulting in counterintuitive proton ejections. The reaction pathways can be controlled through fine-tuning the time-dependent polarization of the pulse. This research highlights the potential of polarization-skewed laser pulses as powerful tweezers for complex laser-molecule interactions.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Andre Ricard, Yunfei Wang, Yoon Sang Lee, Jean-Philippe Sarrette, Ansoon Kim, Yu Kwon Kim
Summary: Analysis of radiative states in N-2/H-2 and N-2/CH4 microwave afterglows at reduced gas pressures revealed that introduction of small percentages of H-2 or CH4 led to size reduction of the early afterglow region, affecting the densities of active species and the incorporation characteristics of N atoms into TiO2 films. These findings are important for process development in nitrogen or carbon doping for thin functional films in photovoltaic and photocatalytic applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Physics, Multidisciplinary
N. Schwegler, D. Holzapfel, M. Stadler, A. Mitjans, I. Sergachev, J. P. Home, D. Kienzler
Summary: This research demonstrates the co-trapping and sideband cooling of a H+2 - 9Be+ ion pair in a cryogenic Paul trap. The chemical lifetime of H+2 is studied in relation to the apparatus temperature, achieving lifetimes of up to 11+6 -3 h at 10 K. Cooling of two translational motion modes is also demonstrated, with an average phonon number corresponding to temperatures of 22(1) and 55(3) mu K, respectively. These results provide a basis for quantum logic spectroscopy experiments of H+2 and other light ions.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Lan Lan, Helen Daly, Rehana Sung, Floriana Tuna, Nathan Skillen, Peter K. J. Robertson, Christopher Hardacre, Xiaolei Fan
Summary: This study investigated the mechanistic details of glucose photoreforming over TiO2 and Pt/m-TiO2 catalysts. The alpha-scission mechanism of glucose oxidation was confirmed by the formation of arabinose and formic acid in the initial oxidation step. The selectivity to sugar products and formic acid differed over Pt/TiO2 and TiO2, with Pt/TiO2 showing lower selectivity to formic acid due to enhanced adsorption/conversion. In situ ATR-IR spectroscopy revealed the presence of molecular formic acid and formate on the surface of both catalysts, suggesting the dominance of formic acid oxidation in glucose photoreforming.
Article
Engineering, Environmental
Yanet Pina-Perez, Enrique Samaniego-Benitez, Jhon Harrison Sierra-Uribe, Federico Gonzalez, Francisco Tzompantzi, Luis Lartundo-Rojas, Angeles Mantilla
Summary: This study demonstrates the synthesis and photocatalytic performance of ZnS-ZnO composites with different compositions of ZnS-c, ZnS-h, and ZnO phases for H2 production. The solvothermal method was used to partially sulfide ZnO at different temperatures (150°C, 200°C, and 250°C) using mono ethylene glycol and thiourea as solvent and sulfur source, respectively. The material characterization involved X-ray diffraction, electron microscopy, UV-visible spectroscopy, X-ray photoelectron microscopy, N2 adsorption-desorption isotherms, and photoelectrochemical techniques. The highest photoactive material was synthesized at 200°C, showing an H2 production rate of 580 µmol h-1 g-1, attributed to the optimized interfacial properties between ZnS-c/ZnS-h and ZnO in the coupled photocatalytic system.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Physical
Qianqian Li, Chen Song, Zhiyu Yan, Xun Cao, Jinhua Wang, Zuohua Huang
Summary: This study investigated the effects of NH3/H-2/N-2 addition on the morphology and nanostructure of soot in ethylene flames. NH3 addition was found to effectively suppress soot formation with smaller particle size and fewer aggregates, while H-2 addition promoted soot formation. The nanostructure of soot particles sampled from NH3-enriched flames was more disordered, while that from H-2-enriched flames was more ordered.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Green & Sustainable Science & Technology
Zhuoheng Tu, Ping Zhang, Mingzhen Shi, Xiaomin Zhang, Youting Wu, Xingbang Hu
Summary: Selective and simultaneous separation of CO and H-2 from N-2 using protic chlorocuprate ionic liquids (PCILs)-based membranes is reported in this study. The selectivity of CO/H-2 can be tuned drastically by varying the Cu(I) content and operating temperature. This work offers a new strategy for designing IL-based membranes for CO and H-2 capture.
Article
Chemistry, Multidisciplinary
Martin Andreas Robert George, Otto Dopfer
Summary: This study investigates the structure, energy, and intermolecular interaction of clusters of the amantadine radical cation with solvent molecules. Three isomers of the radical cation are identified, and the strength of NH ionic H-bonds is measured by solvation-induced red-shifts. The effect of solvation on the energetics is consistent with the observed relative abundance of the isomers. Substituting H with the electron-donating NH2 group substantially lowers the barriers for isomerization reactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Rongxue Shang, Zixuan Zhuang, Yue Yang, Gang Li
Summary: This study systematically investigates the laminar flame speeds of H-2/CH4/air mixtures with CO2 and N-2 dilution through experimental and numerical methods. The results show that the combustion transition from methane dominated to hydrogen inhibited occurs with increasing H-2 fractions, and CO2 has a stronger dilution effect on flame speeds compared to N-2. The experimental data is well-predicted by a semiempirical correlation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Multidisciplinary
Papri Chakraborty, Sami Malola, Marco Neumaier, Patrick Weis, Hannu Hakkinen, Manfred M. Kappes
Summary: The fragmentation dynamics of ligated coinage metal clusters provides insights into their structural and bonding properties. However, the challenges in methodology have limited the investigation of fragment structures. In this study, we used trapped ion mobility mass spectrometry to determine the geometric structures of the primary fragments of [Ag29L12](3-) and compared them to density functional theory calculations. We also observed a new dissociation channel in the further dissociation of [Ag19L6](-), indicating a competition between retaining electronic stability and increasing steric strain of ligands and staples. These findings have potential implications for studying the catalytic behavior of Ag clusters on supports through soft-landing deposition.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Raphael I. I. Petrikat, Sophie T. T. Steiger, Elham Barani, Pit J. J. Boden, Maximilian E. E. Huber, Mark R. R. Ringenberg, Gereon Niedner-Schatteburg, Karin Fink, Sabine Becker
Summary: In this report, the structure of the dinuclear copper(II) dimethylglyoxime complex is presented, which undergoes a cooperativity-driven hydrolysis. The Lewis acidity of the copper centers increases the electrophilicity of the carbon atom in the bridging group of dimethylglyoxime, facilitating nucleophilic attack by water. Depending on the solvent, different oxidation and reduction reactions occur, leading to the formation of different products. Synthetic, theoretical, spectroscopic, and spectrometric methods were used to establish the reaction pathway of this solvent-dependent reaction.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Vanitha R. Naina, Akhil K. Singh, Pascal Rauthe, Sergei Lebedkin, Michael T. Gamer, Manfred M. Kappes, Andreas-Neil Unterreiner, Peter W. Roesky
Summary: In this study, a coumarin functionalized aminodiphosphine was used as a bidentate ligand to synthesize mono-, di-, and trimetallic copper and silver complexes. The ligand exhibited rich luminescence properties, including blue fluorescence and green phosphorescence. Red phosphorescence was observed in the trinuclear complexes at low temperatures. The excited states in these compounds were investigated using femtosecond transient absorption spectroscopy and quantum chemical calculations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Jason E. Colley, Nathan J. Dynak, John R. C. Blais, Michael A. Duncan
Summary: Tunable laser photodissociation spectroscopy measurements and photofragment imaging experiments were conducted to study the dissociation energy of the Fe+(benzene) ion-molecule complex. Additional spectroscopy measurements determined the dissociation energy of Fe+(benzene)2. The dissociation energies of Fe+(benzene) determined from different methods were in agreement with each other, but lower than values obtained from computational chemistry.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Jason E. Colley, Dylan S. Orr, Michael A. Duncan
Summary: Gas-phase ion-molecule complexes of silver cation with benzene or toluene are generated and photodissociated via laser vaporization. The photodissociation process produces the organic cation as the only fragment via a metal-to-ligand charge transfer process. The electronic spectra of the charge-transfer process and other transitions are examined using tunable UV-visible lasers.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Biochemical Research Methods
Papri Chakraborty, Marco Neumaier, Patrick Weis, Manfred M. Kappes
Summary: Cyclodextrin (CD) macrocycles are used to create various supramolecular architectures for applications including gas adsorption, drug delivery, and catalysis. However, predicting their assemblies and identifying possible isomers in CD oligomers has been challenging due to their dynamic nature. In this study, CD oligomers linked by Cu2+ metal ions were created and characterized using mass spectrometry and trapped ion mobility spectrometry, allowing the separation and estimation of isomers. The isomeric heterogeneity reflects the size-specific packing patterns of individual CDs, and the existence of kinetically trapped structures was also observed.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2023)
Article
Chemistry, Physical
Sreekanta Debnath, Alexander Schaefer, Karolina A. Haupa, Dmitry Strelnikov, Jana Roithova, Juraj Jasik, Sergei Lebedkin, Manfred M. Kappes
Summary: Helium tagging photodissociation action spectroscopy and laser-induced fluorescence spectroscopy in neon matrix were used to study the photophysics of electrosprayed rhodamine B cation at low temperatures. The experiments were conducted using He-TAG apparatus for helium tagging and Depo-II machine for LIF measurements. The resulting electronic spectra provide benchmarks for theoretical description of this organic dye.
Article
Chemistry, Inorganic & Nuclear
Verena Hoehn, Wolfram Feuerstein, Florian R. Rehak, Max Kehry, Sergei Lebedkin, Manfred M. Kappes, Wim Klopper, Frank Breher
Summary: The synthesis of C-C-P pre-ligands based on a dicyclohexylphosphine-substituted biphenyl framework has been reported. The pre-ligands can form non-palindromic pincer complexes of Pt-II and PdII through double oxidative addition and subsequent comproportionation or C-H activation. These complexes exhibit similar green phosphorescence in both the solid state and solution, with a more pronounced vibronic pattern observed in the solid samples at cryogenic temperatures.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Tobias Bens, Daniel Marhoefer, Pit Boden, Sophie T. Steiger, Lisa Suntrup, Gereon Niedner-Schatteburg, Biprajit Sarkar
Summary: This study explores the influence of constitutional isomers of pyridyl-1,2,3-triazolylidene mesoionic carbene (MIC) ligands on the photophysical and photochemical properties of tetracarbonyl group 6 metal complexes (M = Cr, Mo, W). The results show that the increased electron density induced by the C-C linked pyridyl-MIC ligand leads to an increased kinetic rate constant for the reformation of the starting species and lower photodissociation quantum yields.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Daniela V. Fries, Matthias P. Klein, Annika Strassner, Maximilian E. Huber, Gereon Niedner-Schatteburg
Summary: In this study, the researchers conducted an IR-PD investigation of tantalum cluster adsorbate complexes. They observed an increase in spectral complexity and redward inhomogeneous broadening during the loading of N-2 molecules. The larger tantalum clusters showed a lack of spontaneous cleavage of N-2, in contrast to the smaller clusters. The study also found that the adsorption capacity of the tantalum clusters remained constant within a certain range of cluster sizes.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Daniela V. Fries, Matthias P. Klein, Annika Strassner, Maximilian E. Huber, Maximilian Luczak, Christopher Wiehn, Gereon Niedner-Schatteburg
Summary: This study investigates the ability of small tantalum clusters to spontaneously cleave N-2 adsorption under cryogenic conditions. Experimental and quantum chemical simulations reveal that all tantalum clusters can efficiently cleave N-2. The study of the tantalum trimer Ta-3 uncovers the reaction paths for cleaving the first and activating the second and third N-2 molecules, and identifies the intermediates involved. The study of the tantalum tetramer Ta-4 elucidates different N-2 coordination modes, adsorption limits, and the formation and desorption of nitrides.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Anna G. Batchelor, Joshua H. Marks, Timothy B. Ward, Michael A. Duncan
Summary: Platinum cation complexes with multiple acetylene molecules were studied using mass spectrometry and infrared laser spectroscopy. Platinum forms cation-π complexes with up to three acetylene molecules, resulting in an asymmetric structure for the three-ligand complex. The formation of reacted structures, such as benzene, is energetically favorable but inhibited by large activation barriers under the experimental conditions.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Jason E. Colley, Nathan J. Dynak, John R. C. Blais, Michael A. Duncan
Summary: Tunable laser photodissociation spectroscopy and photofragment imaging experiments were used to study the Fe+(acetylene) ion-molecule complex. Dissociation occurred above a threshold at 679 nm, with continuous dissociation throughout the visible wavelength region. The complex was found to have a quartet ground state according to time-dependent density functional theory (TD-DFT) predictions. Dissociation energies determined from spectroscopy and photofragment imaging experiments agreed with values obtained from collision-induced dissociation.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Sreekanta Debnath, Alexander Schaefer, Shun Ito, Dmitry Strelnikov, Rabea Schneider, Karolina A. Haupa, Manfred M. Kappes
Summary: By comparing the photophysical properties of a cation and its neutral radical, it was found that the cation exhibited efficient visible photoluminescence while the neutral species showed no emission. Additionally, electronic preresonance Raman spectra were observed for the cation, indicating a significant efficiency factor. These characteristics of the cation/neutral pair may have implications in the field of in vivo bioimaging microscopy and stimulated Raman spectroscopy.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
