Low Temperature Physics最新文献

Propyne confinement in solid parahydrogen: Methyl rotation and site effects 固态对氢中的丙炔约束：甲基旋转和位点效应

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028174

F. Lorin, Anh H. M. Nguyen, A. Gutiérrez-Quintanilla, A. I. Strom, J. Ceponkus, D. T. Anderson, C. Crépin

引用次数: 0

Characterization of H–π and CH–O structures of the 1:1 methanol-benzene complex using matrix isolation infrared spectroscopy 利用基质分离红外光谱鉴定 1:1 甲醇-苯复合物的 H-π 和 CH-O 结构

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028186

Jay C. Amicangelo, Natalie C. Romano, Geoffrey R. Demay, Ian E. Campbell, Joshua D. Wilkins

{"title":"Characterization of H–π and CH–O structures of the 1:1 methanol-benzene complex using matrix isolation infrared spectroscopy","authors":"Jay C. Amicangelo, Natalie C. Romano, Geoffrey R. Demay, Ian E. Campbell, Joshua D. Wilkins","doi":"10.1063/10.0028186","DOIUrl":"https://doi.org/10.1063/10.0028186","url":null,"abstract":"Matrix isolation infrared spectroscopy was used to characterize a 1:1 complex of methanol (CH3OH) and benzene (C6H6). Co-deposition experiments with CH3OH and C6H6 were performed at 17–20 K using nitrogen and argon as the matrix gases. Several new infrared peaks in the co-deposition spectra were observed near the fundamental absorptions of the CH3OH and C6H6 parent molecules and these new peaks have been attributed to CH3OH–C6H6 complexe. Experiments were also performed with isotopic CD3OD and C6D6 and the corresponding infrared peaks of the isotopologue complexes have also been observed. Theoretical calculations were performed for the CH3OH–C6H6 complex using the M06-2X, ωB97X-D, MP2, and CCSD(T) methods with the aug-cc-pVDZ and aug-cc-pVTZ basis sets. Full geometry optimizations followed by vibrational frequency calculations were performed for several initial starting geometries and three stable minima were found for the CH3OH–C6H6 complex. The first has the CH3OH above the C6H6 ring with the OH hydrogen interacting with the π cloud of the ring (H–π complex), the second has the CH3OH above the C6H6 ring with the OH oxygen interacting with one or two of the C–H bonds of the ring (CH–O 1 complex), and the third has the CH3OH towards the side of the C6H6 ring with the OH oxygen interacting with two of the C–H bonds of the ring (CH–O 2 complex). The H–π complex structure is predicted to be the lower energy structure by ∼8 kJ/mol compared to the two CH–O structures. Comparing the theoretically predicted infrared spectra for the optimized CH3OH–C6H6 complex structures to the experimentally observed infrared peaks in argon and nitrogen matrices, it is concluded that in the argon matrices only the H–π complex structure is being observed, whereas in the nitrogen matrices the H–π complex and CH–O 1 complex structures are being observed.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"3 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-resolution electronic spectroscopy of buffer-gas-cooled metal-phthalocyanines 缓冲气冷却金属酞菁的高分辨率电子光谱学

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028188

Yuki Miyamoto, Masaaki Baba, Katsunari Enomoto, Ayami Hiramoto, Kana Iwakuni, Susumu Kuma

引用次数: 0

Photochemistry of cyanoacetylene in solid argon revisited 固态氩中氰乙炔的光化学再研究

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028163

Thomas G. Custer, Claudine Crépin, Marcin Gronowski, Arun-Libertsen Lawzer, Robert Kołos

引用次数: 0

Enhanced luminescence of oxygen atoms in solid molecular nitrogen nanoclusters 固态分子氮纳米团簇中氧原子的发光增强

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028138

O. Korostyshevskyi, C. K. Wetzel, D. M. Lee, V. V. Khmelenko

{"title":"Enhanced luminescence of oxygen atoms in solid molecular nitrogen nanoclusters","authors":"O. Korostyshevskyi, C. K. Wetzel, D. M. Lee, V. V. Khmelenko","doi":"10.1063/10.0028138","DOIUrl":"https://doi.org/10.1063/10.0028138","url":null,"abstract":"We studied luminescence accompanied an injection of the nitrogen-helium gas mixture after passing discharge into dense cold helium gas. Initially, when the experimental beaker was filled with superfluid helium and the nitrogen-helium gas was injected into bulk superfluid helium at T ≈ 1.5 K, the dominant band in the emission spectra was the α-group of nitrogen atoms. At these conditions, the nanoclusters of molecular nitrogen with high concentrations of stabilized nitrogen atoms were formed. When superfluid helium was evaporated from the beaker and the temperature at the bottom of the beaker was increased to T ≈ 20 K, we observed a drastic change in the luminescence spectra. The β-group of oxygen atoms was dominated in the luminescence spectra, and the emission of the α-group became small. At high temperatures (T ≈ 20 K), most of the nitrogen atoms recombine on the surface of N2 nanoclusters with the formation of excited nitrogen molecules. We explained the effect of the enhancement of β-group emission by effective energy transfer from excited nitrogen molecules to the stabilized impurity oxygen atom inside N2 nanoclusters.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"19 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Direct UV absorption spectra of CO2+ in solid neon 固态氖中 CO2+ 的直接紫外吸收光谱

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028139

Wen-Jian Huang, Sheng-Lung Chou, Shu-Yu Lin, Hui-Fen Chen, Yu-Jong Wu

引用次数: 0

Helium 1s photoemission and photon stimulated desorption of He+ ions by double excitations from adsorbed helium layers: Zero-point motion and matrix effects 氦 1s 光发射和 He+ 离子受吸附氦层双激发的光子刺激解吸：零点运动和矩阵效应

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028136

S. J. Riepl, S. Kossler, J. Braun, J. Minár, J. V. Barth, P. Feulner

引用次数: 0

Revisiting structural, vibrational, and photochemical data of matrix-isolated simple hydantoins — Common features and substituent effects 重新审视基质分离简单海因的结构、振动和光化学数据 - 共同特征和取代基效应

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028129

Rui Fausto, Gulce O. Ildiz, Bernardo A. Nogueira

{"title":"Revisiting structural, vibrational, and photochemical data of matrix-isolated simple hydantoins — Common features and substituent effects","authors":"Rui Fausto, Gulce O. Ildiz, Bernardo A. Nogueira","doi":"10.1063/10.0028129","DOIUrl":"https://doi.org/10.1063/10.0028129","url":null,"abstract":"Characteristic features of the structure (geometries, electronic structures), vibrational spectra (infrared), and photochemistry of a series of simple hydantoins (parent hydantoin, 1-methylhydantoin, 5-methylhydantoin, and 5-acetic acid hydantoin), and effects of substituent on these properties, are reviewed in a comparative comprehensive perspective taken as a basis the low-temperature matrix isolation infrared spectroscopy and electronic structure quantum chemistry data we have reported before for the individual compounds. It is shown that the hydantoin moiety shows a general tendency towards planarity (or quasi-planarity), mostly determined by the π-electron delocalization in the system, in which the two nitrogen atoms are extensively involved and, in the molecules studied, also counts with the involvement of the π-type orbitals of the –C5H2– or –C5HR– (with R ˭ CH3 or CH2COOH in 5-methylhydantoin and 5-acetic acid hydantoin, respectively) fragment (hyperconjugation). The geometries and charge density analyses of the compounds also show that the main electronic effects in the hydantoin ring are the N-to-(C ˭ O) π-electron donation, and the σ system back-donation from the σ-lone electron pairs of the oxygen atoms to the ring. The frequencies of the bands observed in the matrix-isolation infrared spectra (Ar; 10 K) of the different compounds that are assigned to the carbonyl and amine fragments are discussed comparatively, and substituent effects are assessed. Finally, the UV-induced (λ = 320 nm) photochemistry of the hydantoins is shown to share a common pattern, leading to the concerted extrusion of isocyanic acid and carbon monoxide, accompanied by an imine derivative that depends upon the specific hydantoin reactant. An additional photofragmentation pathway, most probably involving nitrene intermediacy, also takes place for 1-methylhydantoin, indicating a specific effect of the substitution at position 1 of the hydantoin ring on the photofragmentation of hydantoins.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"60 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unveiling the conformational diversity of succinic acid: Insights from IR spectroscopy and quantum chemical calculations 揭开琥珀酸构象多样性的面纱：红外光谱和量子化学计算的启示

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028183

Lucas Da Silva Sa, Ander Camiruaga, Katia Le Barbu-Debus, Jordan A. Claus, Manuel Goubet, Rodolphe Pollet, Wutharath Chin

引用次数: 0

Size distribution of helium droplets in the condensation regime of a pulsed beam 脉冲光束凝结状态下氦液滴的尺寸分布

IF 0.8 4区物理与天体物理

Low Temperature Physics Pub Date : 2024-09-04 DOI: 10.1063/10.0028187

A. Iguchi, A. Hirota, S. Menk, T. Yamaguchi, H. Tanuma, J. R. Harries, S. Kuma, T. Azuma

引用次数: 0