scholarly journals Optomechanical switching of adsorption configurations of polar organic molecules by UV radiation pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kowsalya Arumugam ◽  
Abhishake Goyal ◽  
Hong-Ming Chen ◽  
Jing-Huan Dai ◽  
Mau-Fu Gao ◽  
...  
Keyword(s):  
Radiation Pressure ◽  
Organic Molecule ◽  
Organic Molecules ◽  
Photon Flux ◽  
Photoemission Spectroscopy ◽  
Molecular Plane ◽  
Vacuum Level ◽  
Line Shapes ◽  
Cl Atoms ◽  
Cl Atom

AbstractUsing photoemission spectroscopy (PES), we have systematically investigated the behavior of polar organic molecule, chloroaluminum phthalocyanine (ClAlPc), adsorbed in the Cl-down configuration on the Ag(111) substrate at low temperature − 195 °C under UV irradiation with a range of different photon fluxes. Judging from the evolution of photoemission spectral line shapes of molecular energy states, we discovered that the Cl atoms are so robustly anchored at Ag(111) that the impinging photons cannot flip the ClAlPc molecules, but instead they crouch them down due to radiation pressure; we observe that the phthalocyanine (Pc) lobes bend down to interact with Ag atoms on the substrate and induce charge transfer from them. As photon flux is increased, radiation pressure on the Pc plane initiates tunneling of the Cl atom through the molecular plane to turn the adsorption configuration of ClAlPc from Cl-down to an upheld Cl-up configuration, elucidating an optomechanical way of manipulating the dipole direction of polar molecules. Finally, work function measurements provide a distinct signature of the resulting upheld Cl-up configuration as it leads to a large increase in vacuum level (VL), ~ 0.4 eV higher than that of a typical flat-on Cl-up configuration driven by thermal annealing.

UV Photoemission Study of Interfaces Related to Organic EL Devices

1997 ◽  
Vol 488 ◽  
Author(s):  
Kiyoshi Sugiyama ◽  
Kazuhiko Seki ◽  
Eisuke Ito ◽  
Yukio Ouchi ◽  
Hisao ISHII
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Electronic Structures ◽  
Organic Molecule ◽  
Negative Charge ◽  
Photoemission Spectroscopy ◽  
Level Shift ◽  
Vacuum Level ◽  
Organic Electroluminescent ◽  
Photoemission Study

AbstractInterfacial electronic structures related to organic electroluminescent (EL) devices were studied by UV photoemission spectroscopy (UPS). The two classes of interfaces studied were: (1) interfaces in a typical multilayer device AI/AIq3TPD/ITO, where Alq3 is tris(8-hydroxyquinolino)- aluminum, TPD is N,N×-diphenyl-NN×-(3-methylphenyl)- 1, 1‘-biphenyl-4,4’-diamine, and ITO is indium tin oxide, and (2) TTN/metals and TCNQ/metals interfaces, where TTN is tetrathianaphthacene and TCNQ is tetracyanoquinodimethane. The UPS studies of the specimen formed by the successive deposition of TPD, Alq3, and Al on ITO revealed interfacial energy diagrams, with the vacuum level shift of - 0.25 eV (downward) and - 0.1 eV (downward) at the TPD / ITO and the Alq3 / TPD interfaces, respectively. The deposition of TTN and TCNQ on metals showed opposite direction of the shift of the vacuum level, with the positive and negative charge at the vacuum side. This can be explained by considering the chargetransfer between the metal and the organic molecule, with these directions being consistent with the electron donating and accepting ability of these molecules.

Perchlorophenalenyl radical, C13Cl9: a modulated structure with nine threefold-symmetric molecules in the asymmetric unit

2001 ◽  
Vol 57 (5) ◽  
pp. 680-691 ◽  
Author(s):  
P. A. Koutentis ◽  
R. C. Haddon ◽  
R. T. Oakley ◽  
A. W. Cordes ◽  
C. P. Brock
Keyword(s):  
Density Functional ◽  
Rotational Symmetry ◽  
Structural Complexity ◽  
Asymmetric Unit ◽  
Functional Theory ◽  
Modulated Structure ◽  
Molecular Plane ◽  
Rotation Axes ◽  
Cl Atoms ◽  
Cl Atom

The odd-alternant perchlorophenalenyl radical, C13Cl9, forms molecular stacks centered on crystallographic threefold rotation axes, but the spacing within the stacks (3.78 Å) is too large to allow good overlap of the orbitals in which the spin density is localized. The radical is ruffled because of the intramolecular repulsions between α Cl atoms (the Cl...Cl peri interactions); the average displacement of an α Cl atom from the molecular plane is ∼0.7 Å. The deviations from molecular planarity do not, however, determine the spacing within the stacks, which is determined instead by interactions between stacks. The modulations found in the P3c1 superstructure are a response to the short interstack contacts that would occur in the average pseudocell structure (R\bar 3m, c′ = c/6). The primary modulation is a pattern of enantiomeric alternation; a secondary modulation involves small rotations of the molecules around their threefold axes. The number (9) of independent molecules in the true cell is exceptionally large because of the conflict between the preference within the molecular stacks for threefold rotational symmetry and the preference in directions perpendicular to the stack axes for twofold alternation of enantiomers. The structural complexity reduces the precision of the distances and angles determined, but the average values found are in excellent agreement with those calculated by density functional theory.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

The Bond N -Cl. A Spectroscopic (35Cl-NQR, IR) Investigation

1994 ◽  
Vol 49 (6) ◽  
pp. 695-702 ◽  
Author(s):  
B. Thimme Gowda ◽  
Alarich Weiss
Keyword(s):  
Phenyl Ring ◽  
Electron Distribution ◽  
Inductive Effect ◽  
Aqueous Media ◽  
Phenyl Group ◽  
Vibration Frequencies ◽  
Resonance Frequencies ◽  
35Cl Nqr ◽  
Cl Atoms ◽  
Cl Atom

Abstract Chlorine bound to nitrogen is an interesting oxidizing agent in aqueous, partial aqueous and non-aqueous media. One can assume that the oxidizing action of the chlorine depends on the polarization of the Cl atom in the bond N -Cl which will depend on the electron distribution in the ligands R and R″ of the configuration R -NCl -CO -R″. 17 compounds were synthesized with R = substituted phenyl radical C6H5-y Xy, X = Cl, NO2, R″ = CH2Cl. The 35Cl NQR frequencies are observed in the range 52 to 54 MHz (T = 77 K) for the Cl(N) 34 to 37 MHz for the phenyl chlorines and the CH2Cl group. Their temperature dependence was followed up to 300 K. Therefrom the assignment of the resonance to certain Cl-atoms in the molecules is possible. Generally, the substitution of a negative substituent X (Cl, NO2) in the phenyl ring raises the resonance frequencies; the influence of the CH2Cl group on the N -Cl bond is weak. Strong is the influence of the carbonyl group on the N -C l bond. The IR group frequencies ν(C = O) are found in the range 1680 ≤ ν (C = O)/ cm−1≤ 1717, shifted up by ≤ 20 cm−1 compared to the corresponding acetamide R ⎯ NH ⎯CO ⎯ R″. Influence of the phenyl ring substitution on ν (C = O) does not follow a simple law of inductive effect. Also a correlation between the vibration frequencies of the N ⎯ Cl group and the phenyl group substitution is not found.

Die Reaktionen chlorierter Äthylene mit hydratisierten Elektronen und OH-Radikalen in wäßriger Lösung / The Reaction of Chlorinated Ethylenes with Hydrated Electrons and OH-Radicals in Aqueous Solution

1971 ◽  
Vol 26 (11) ◽  
pp. 1108-1116 ◽  
Author(s):  
R. Köster ◽  
K.-D. Asmus
Keyword(s):  
Rate Constant ◽  
Oh Radicals ◽  
Capture Process ◽  
Chlorinated Ethylenes ◽  
Diffusion Controlled ◽  
Hydrated Electrons ◽  
Cl Atoms ◽  
Type Radical ◽  
Cl Atom ◽  
Steric Hinderance

The reactions of chlorinated ethylenes with hydrated electrons and OH radicals have been investigated by using the method of pulse radiolysis. In addition γ-ray experiments were carried out. The reduction of the solutes occurs via a dissoziation electron capture process. The rate constant for the reaction of eaq⊖ with the more chlorinated compounds is essentially diffusion controlled (k= (1 - 2×1010 l-mole-1 sec-1). Vinylchloride and 1,2-trans-dichloroethylene react more slowly. This can be related to the higher stability of the C-Cl bond in these compounds.Hydroxyl radicals add to the C=C double bond of the chlorinated ethylenes. The rate constant for the reaction with vinylchloride was determined to 7.1 × 109 1 · mole-1 sec-1, and decreases with increasing degree of chlorination of the ethylenes. This effect is explained by the decreasing electron density on the C-atoms and steric hinderance. The hydroxyl radical always adds to the C-atom carrying the smallest number of Cl-atoms. In its reaction with 1,2-dichloro-, trichloro- and tetrachloroethylene a radical is produced with an OH group and a Cl-atom on the same C-atom. It eliminates HCl to form a C=O bond with k>7 × 105 sec-1. The type radical produced in this reaction has an optical absorption in the near UV (ε265 nm = (1-3)×103 1 · mole-1 cm-1).The OH radical addition products of vinylchloride and 1,1-dichloroethylene do not eliminate HCl and have no absorption in the visible and near UV.

scholarly journals Organic Molecule Detection Based on SERS in Microfluidics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xin Zhang ◽  
Haiyan Zhang ◽  
Sheng Yan ◽  
Zugang Zeng ◽  
Anshou Huang ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
Ag Nanoparticles ◽  
Organic Molecule ◽  
Organic Molecules ◽  
Chemical Reduction ◽  
Fdtd Method ◽  
Great Influence ◽  
High Sensitivity ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate

AbstractSensitive in situ detection of organic molecules is highly demanded in environmental monitoring. In this work, the surface enhanced Raman spectroscopy (SERS) is adopted in microfluidics to detect the organic molecules with high accuracy and high sensitivity. Here the SERS substrate in microchannel consists of Ag nanoparticles synthesized by chemical reduction. The data indicates the fabrication conditions have great influence on the sizes and distributions of Ag nanoparticles, which play an important role on the SERS enhancement. This result is further confirmed by the simulation of electromagnetic field distributions based on finite difference time domain (FDTD) method. Furthermore, the SERS spectra of organic molecule (methylene blue) obtained in this plasmonic microfluidic system exhibit good reproducibility with high sensitivity. By a combination of SERS and microfluidics, our work not only explores the research field of plasmonics but also has broad application prospects in environmental monitoring.

Reductive dechlorination pathways of chloro organics under anaerobic conditions

1996 ◽  
Vol 34 (5-6) ◽  
pp. 489-494 ◽  
Author(s):  
Sridhar Susarla ◽  
Shigeki Masunaga ◽  
Yoshitaka Yonezawa
Keyword(s):  
Reductive Dechlorination ◽  
Organic Chemicals ◽  
Anaerobic Conditions ◽  
Sediment Slurry ◽  
Transformation Pathways ◽  
Lag Period ◽  
Cl Atoms ◽  
Cl Atom

The transformation pathways of chloroanilines (CAs), chlorobenzenes (CBs) and chlorophenols (CPs) were examined in anaerobic sediment collected from the Tsurumi river, Japan. The sediment was pre-exposed to various organic chemicals from the surrounding industries and appears to be sulfidogenic. Experiments were carried out for each compound in the sediment slurry, which was spiked at a desired concentration. The transformation of the parent substrate and the appearance of its metabolites were monitored for a year. All the compounds transformed without any lag period. For CBs, the preferential Cl removal was in the order: two Cl atoms on adjacent carbon atoms > one Cl atom on adjacent carbon > no adjacent Cl atom on the carbon. In case of CPs, ortho dechlorination was the preferred pathway, while for CAs, sequential removal of ortho and para positions was observed.

scholarly journals Tropospheric OH and Cl levels deduced from non-methane hydrocarbon measurements in a marine site

2007 ◽  
Vol 7 (17) ◽  
pp. 4661-4673 ◽  
Author(s):  
C. Arsene ◽  
A. Bougiatioti ◽  
M. Kanakidou ◽  
B. Bonsang ◽  
N. Mihalopoulos
Keyword(s):  
Eastern Mediterranean ◽  
Regional Scale ◽  
Oh Radicals ◽  
Atom Concentration ◽  
Diel Variations ◽  
Marine Site ◽  
Cl Atoms ◽  
Cl Atom ◽  
Good Agreement

Abstract. In situ continuous hourly measurements of C2–C8 non-methane hydrocarbons (NMHCS) have been performed from March to October 2006 at two coastal locations (natural and rural) on the island of Crete, in the Eastern Mediterranean. Well defined diel variations were observed for several short lived NMHCS (including ethene, propene, n-butane, n-pentane, n-hexane, 2-methyl-pentane). The daytime concentration of hydroxyl (OH) radicals estimated from these experimental data varied from 1.3×106 to ~4.0×106 radical cm−3, in good agreement with box-model simulations. In addition the relative variability of various hydrocarbon pairs (at least 7) was used to derive the tropospheric levels of Cl atoms. The Cl atom concentration has been estimated to range between 0.6×104 and 4.7×104 atom cm−3, in good agreement with gaseous hydrochloric acid (HCl) observations in the area. Such levels of Cl atoms can be of considerable importance for the oxidation capacity of the troposphere on a regional scale.

Sign in / Sign up

Export Citation Format

Share Document