scholarly journals Photochemical R2PI study of chirality and intermolecular forces in supersonic beam

2001 ◽  
Vol 3 (4) ◽  
pp. 223-227 ◽  
Author(s):  
A. Giardini Guidoni ◽  
S. Piccirillo ◽  
D. Scuderi ◽  
M. Satta ◽  
T. M. Di Palma ◽  
...  
Keyword(s):  
Excited States ◽  
Molecular Beam ◽  
Intermolecular Forces ◽  
Excitation Spectra ◽  
Supersonic Molecular Beam ◽  
Spectral Shifts ◽  
Band Origin ◽  
Solvent Molecules ◽  
The One ◽  
Diastereomeric Complexes

One and two-color, mass selected R2PI spectra of theS1←S0transitions in the bare(+)-(R)- 1-phenyl-1-ethanol(ER) and its complexes with different solvent molecules (solv) (-)-(R)-2-butanol(BR) or(+)-(S)-2-butanol(BS), (—)-(R)-2-pentanol (TR) or(+)-(S)-2-pentanol(TS) and(-)-(R)-2-butylamine(AR) or(+)-(S)-2-butylamine(AS), have been recorded after a supersonic molecular beam expansion. The one-color R2PI excitation spectra of the diastereomeric complexes are characterized by significant shifts of their band origin relative to that of bareER. The extent and the direction of these spectral shifts are found to depend upon the structure and the configuration ofsolvand are attributed to different short-range interactions in the ground and excited states of the complexes. In analogy with other diastereomeric complexes, the phenomenological binding energy of the homochiral cluster is found to be greater than that of the heterochiral one. Preliminary measurements of excitation spectrum of(+)-(R)-1-Indanol(IR) is also reported.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

Observation of Edge Filamentary Structure Motion during Supersonic Molecular-Beam Injection Using a Fast Camera in Heliotron J

2013 ◽  
Vol 8 (0) ◽  
pp. 1402066-1402066 ◽  
Author(s):  
Linge ZANG ◽  
Nobuhiro NISHINO ◽  
Tohru MIZUUCHI ◽  
Shinsuke OHSHIMA ◽  
Masaki TAKEUCHI ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Filamentary Structure ◽  
Supersonic Molecular Beam ◽  
Beam Injection

Supersonic molecular beam and static gas phase spectroscopy of intermolecular hot bands associated with ν116O12C---1H19F

1988 ◽  
Vol 152 (1) ◽  
pp. 87-93 ◽  
Author(s):  
K. McMillan ◽  
D. Bender ◽  
M. Eliades ◽  
D. Danzeiser ◽  
B.A. Wofford ◽  
...  
Keyword(s):  
Gas Phase ◽  
Molecular Beam ◽  
Supersonic Molecular Beam ◽  
Gas Phase Spectroscopy

scholarly journals Influence of TOPO and TOPO-CdSe/ZnS Quantum Dots on Luminescence Photodynamics of InP/InAsP/InPHeterostructure Nanowires

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 640
Author(s):  
Artem I. Khrebtov ◽  
Vladimir V. Danilov ◽  
Anastasia S. Kulagina ◽  
Rodion R. Reznik ◽  
Ivan D. Skurlov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Excited States ◽  
Molecular Beam ◽  
Surface Passivation ◽  
Low Energy ◽  
Trioctylphosphine Oxide ◽  
Reverse Transfer ◽  
Semiconductor Heterostructure ◽  
Ligand Type

The passivation influence by ligands coverage with trioctylphosphine oxide (TOPO) and TOPO including colloidal CdSe/ZnS quantum dots (QDs) on optical properties of the semiconductor heterostructure, namely an array of InP nanowires (NWs) with InAsP nanoinsertion grown by Au-assisted molecular beam epitaxy on Si (111) substrates, was investigated. A significant dependence of the photoluminescence (PL) dynamics of the InAsP insertions on the ligand type was shown, which was associated with the changes in the excitation translation channels in the heterostructure. This change was caused by a different interaction of the ligand shells with the surface of InP NWs, which led to the formation of different interfacial low-energy states at the NW-ligand boundary, such as surface-localized antibonding orbitals and hybridized states that were energetically close to the radiating state and participate in the transfer of excitation. It was shown that the quenching of excited states associated with the capture of excitation to interfacial low-energy traps was compensated by the increasing role of the “reverse transfer” mechanism. As a result, the effectiveness of TOPO-CdSe/ZnS QDs as a novel surface passivation coating was demonstrated.

scholarly journals Investigation of Solubility Behavior of Canagliflozin Hydrate Crystals Combining Crystallographic and Hirshfeld Surface Calculations

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 298
Author(s):  
Yefen Zhu ◽  
Yanlei Kang ◽  
Ling Zhu ◽  
Kaxi Yu ◽  
Shuai Chen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Intermolecular Forces ◽  
Hirshfeld Surface ◽  
Reversible Inhibitor ◽  
Solubility Behavior ◽  
Hydrogen Bond Networks ◽  
Solvent Molecules ◽  
First Time ◽  
Better Than

Canagliflozin (CG) was a highly effective, selective and reversible inhibitor of sodium-dependent glucose co-transporter 2 developed for the treatment of type 2 diabetes mellitus. The crystal structure of CG monohydrate (CG-H2O) was reported for the first time while CG hemihydrate (CG-Hemi) had been reported in our previous research. Solubility and dissolution rate results showed that the solubility of CG-Hemi was 1.4 times higher than that of CG-H2O in water and hydrochloric acid solution, and the dissolution rates of CG-Hemi were more than 3 folds than CG-H2O in both solutions. Hirshfeld surface analysis showed that CG-H2O had stronger intermolecular forces than CG-Hemi, and water molecules in CG-H2O participated three hydrogen bonds, forming hydrogen bond networks. These crystal structure features might make it more difficult for solvent molecules to dissolve CG-H2O than CG-Hemi. All these analyses might explain why the dissolution performance of CG-Hemi was better than CG-H2O. This work provided an approach to predict the dissolution performance of the drug based on its crystal structure.

Flow visualization and density measurement of the supersonic molecular beam for fusion plasma fueling

2021 ◽  
Vol 92 (4) ◽  
pp. 043539
Author(s):  
Guoliang Xiao ◽  
Jiao Yin ◽  
Chengyuan Chen ◽  
Beibin Feng ◽  
Wulyu Zhong ◽  
...  
Keyword(s):  
Flow Visualization ◽  
Molecular Beam ◽  
Density Measurement ◽  
Fusion Plasma ◽  
Supersonic Molecular Beam ◽  
Plasma Fueling

scholarly journals Synthesis of single layer graphene on Cu(111) by C60 supersonic molecular beam epitaxy

RSC Advances ◽  
2016 ◽  
Vol 6 (44) ◽  
pp. 37982-37993 ◽  
Author(s):  
Roberta Tatti ◽  
Lucrezia Aversa ◽  
Roberto Verucchi ◽  
Emanuele Cavaliere ◽  
Giovanni Garberoglio ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Molecular Beam ◽  
Materials Science ◽  
Single Layer ◽  
Molecular Beams ◽  
Single Layer Graphene ◽  
Physical Processes ◽  
Supersonic Molecular Beam ◽  
Layer Graphene ◽  
High Kinetic Energy

High kinetic energy impacts between inorganic surfaces and molecular beams seeded by organics represent a fundamental tool in materials science, particularly when they activate chemical–physical processes leading to nanocrystals' growth.

Comparison of the Optical Properties of Er3+ Doped Gallium Nitride Prepared by Metalorganic Molecular Beam Epitaxy (MOMBE) and Solid Source Molecular Beam Epitaxy (SSMBE)

1999 ◽  
Vol 595 ◽  
Author(s):  
U. Hömmerich ◽  
J. T. Seo ◽  
J. D. MacKenzie ◽  
C. R. Abernathy ◽  
R. Birkhahn ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Excited States ◽  
Room Temperature ◽  
Molecular Beam ◽  
Average Lifetime ◽  
Green Luminescence ◽  
Si Substrates ◽  
Lifetime Analysis ◽  
Metalorganic Molecular Beam Epitaxy ◽  
Er Doped

AbstractWe report on the luminescence properties of Er doped GaN grown prepared by metalorganic molecular beam epitaxy (MOMBE) and solid-source molecular beam epitaxy (SSMBE) on Si substrates. Both types of samples emitted characteristic 1.54 µm PL resulting from the intra-4f Er3+ transition 4I13/2→4I15/2. Under below-gap excitation the samples exhibited very similar 1.54 µm PL intensities. On the contrary, under above-gap excitation GaN: Er (SSMBE) showed ∼80 times more intense 1.54 µm PL than GaN: Er (MOMBE). In addition, GaN: Er (SSMBE) also emitted intense green luminescence at 537 nm and 558 nm, which was not observed from GaN: Er (MOMBE). The average lifetime of the green PL was determined to be 10.8 µs at 15 K and 5.5 µs at room temperature. A preliminary lifetime analysis suggests that the decrease in lifetime is mainly due to the strong thermalization between the 2H11/2 and 4S3/2 excited states. Nonradiative decay processes are expected to only weakly affect the green luminescence.

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