scholarly journals Resonance-Enhanced Raman Spectroscopy on Explosives Vapor at Standoff Distances

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Anneli Ehlerding ◽  
Ida Johansson ◽  
Sara Wallin ◽  
Henric Östmark
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Wavelength Range ◽  
Vapor Phase ◽  
Cross Sections ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Resonance Enhancement ◽  
Enhancement Factors ◽  
532 Nm

Resonance-enhanced Raman spectroscopy has been used to perform standoff measurements on nitromethane (NM), 2,4-DNT, and 2,4,6-TNT in vapor phase. The Raman cross sections for NM, DNT, and TNT in vapor phase have been measured in the wavelength range 210–300 nm under laboratory conditions, in order to estimate how large resonance enhancement factors can be achieved for these explosives. The results show that the signal is enhanced up to 250,000 times for 2,4-DNT and up to 60,000 times for 2,4,6-TNT compared to the nonresonant signal at 532 nm. Realistic outdoor measurements on NM in vapor phase at 13 m distance were also performed, which indicate a potential for resonance Raman spectroscopy as a standoff technique for detection of vapor phase explosives. In addition, the Raman spectra of acetone, ethanol, and methanol were measured at the same wavelengths, and their influence on the spectrum from NM was investigated.

scholarly journals Short-Time Photodissociation Dynamics of 1-Chloro-2-Iodoethane From Resonance Raman Spectroscopy

1999 ◽  
Vol 19 (1-4) ◽  
pp. 71-74 ◽  
Author(s):  
Xuming Zheng ◽  
David Lee Phillips
Keyword(s):  
Raman Spectroscopy ◽  
Absorption Spectrum ◽  
Raman Spectra ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Time Dependent ◽  
Internal Excitation ◽  
Band Absorption ◽  
Resonance Raman Spectra ◽  
Short Time

We have obtained A-band absorption resonance Raman spectra of 1-chloro-2- iodoethane in cyclohexane solution. We have done preliminary time-dependent wavepacket calculations to simulate the resonance Raman intensities and absorption spectrum in order to learn more about the short-time photodissociation dynamics. We compare our preliminary results for 1-chloro-2-iodoethane with previous resonance Raman results for iodoethane and find that there appears to be more motion along non- C—I stretch modes for 1-chloro-2-iodoethane than for iodoethane. This is consistent with results of TOF photofragment spectroscopy experiments which indicate much more internal excitation of the photoproducts from 1-chloro-2-iodoethane photodissociation than the photoproducts from iodoethane photodissociation.

scholarly journals Non-invasive analysis of stored red blood cells using diffuse resonance Raman spectroscopy

The Analyst ◽  
2018 ◽  
Vol 143 (24) ◽  
pp. 5950-5958 ◽  
Author(s):  
Rekha Gautam ◽  
Joo-Yeun Oh ◽  
Rakesh P. Patel ◽  
Richard A. Dluhy
Keyword(s):  
Raman Spectroscopy ◽  
Red Blood Cells ◽  
Raman Spectra ◽  
Blood Cells ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Non Invasive

A method to acquire the Raman spectra of sub-surface components using diffusely focused radiation in a microscope sampling configuration is described.

Adsorption of benzidines and anilines on Cu- and Fe-montmorillonites studied by resonance Raman spectroscopy

Clay Minerals ◽  
1988 ◽  
Vol 23 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Y. Soma ◽  
M. Soma
Keyword(s):  
Raman Spectroscopy ◽  
Double Bond ◽  
Raman Spectra ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Vapour Phase ◽  
Acid Sites ◽  
Type Structure ◽  
Cation Radicals

AbstractResonance Raman spectroscopy has been used to observe the formation of cation radicals in the adsorption of N,N,N',N'-tetramethylbenzidine (TMBD), benzidine, N,Ndimethylaniline (DMA) and aniline on Na-, Cu- and Fe-montmorillonites. Cation radicals of benzidine and TMBD, and their dications were formed at acid sites on the montmorillonite surface, or through the reduction of Cu or Fe interlayer ions, and were adsorbed in the interlayer. Their structures are represented by biphenoquinone type structure, where the inter-ring CC bond and the ring C-N bond have double bond characters. It was demonstrated from Raman spectra that DMA and aniline adsorbed on Cu-montmorillonite from the vapour phase dimerize to form TMBD and benzidine dications.

Resonant Raman scattering study of BexZn1−xO thin films grown on sapphire by molecular beam epitaxy

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744067 ◽  
Author(s):  
Yu-Chao Wang ◽  
Long-Xing Su ◽  
Yu Zhao ◽  
Jian-Feng Liu ◽  
Zheng-Chuan Shen ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Phonon Mode ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Mode Frequency ◽  
Wave Number ◽  
Mode Vibration ◽  
Scattering Study ◽  
The Stability

Resonance Raman spectra of Be[Formula: see text]Zn[Formula: see text]O alloy materials were studied using 325 nm Laser. The research showed that the Raman spectra of Be[Formula: see text]Zn[Formula: see text]O alloys presents a dual-mode vibration. Compare Be[Formula: see text]Zn[Formula: see text]O alloy with ZnO single crystal, the A1 (LO) phonon vibration mode of Be[Formula: see text]Zn[Formula: see text]O alloy moved to the larger wave number direction. The position of A1 (LO) phonon vibration modes of Be[Formula: see text]Zn[Formula: see text]O and Be[Formula: see text]Zn[Formula: see text]O was 580 cm[Formula: see text] and 582 cm[Formula: see text], respectively. In addition, the temperature-dependent Raman spectroscopy was employed for Be[Formula: see text]Zn[Formula: see text]O, and the phonon mode frequency shift with temperature was studied in detail. Finally, the stability of the polar and nonpolar Be[Formula: see text]Zn[Formula: see text]O alloy materials was studied using resonance Raman spectroscopy. The results showed that the A1 (LO) phonon mode frequency of polar Be[Formula: see text]Zn[Formula: see text]O alloy remained in the same position, while the nonpolar Be[Formula: see text]Zn[Formula: see text]O alloys moved nearly 3.5 cm[Formula: see text] to larger direction after being placed in the air for two years. The reason may be that the stability of the nonpolar Be[Formula: see text]Zn[Formula: see text]O alloy is relatively poor upon interaction with molecule such as H2O, O2 in the air.

scholarly journals Mesoporous Silica Functionalized by Nickel-Cyclam Molecules: Preparation and Resonance Raman Study

2012 ◽  
Vol 35 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Magdalena Laskowska ◽  
Łukasz Laskowski ◽  
Kazimierz Dzilinski
Keyword(s):  
Raman Spectroscopy ◽  
Mesoporous Silica ◽  
Raman Spectra ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Nickel Ions ◽  
Methods Of Synthesis ◽  
Raman Study ◽  
Resonance Raman Spectra ◽  
And Shifts

Abstract Mesoporous silica SBA-15 functionalized by (1,4,8,11-tetraazacyclotetradecane) cyclam groups containing nickel ions (Ni-cyclam) was synthesized by two different approaches, and investigated by resonance Raman spectroscopy. Vibrational features of organometallic moleculess are analyzed for (Ni-cyclam) groups grafted in the silica pores. An assignment of bands in resonance Raman spectra was done to monitor the structure and properties of the mesoporous silica material with regard to the methods of synthesis used in this study. It was shown, that Raman scattering can be useful for probing of functionalization's efficiency of mesoporous silica. On the base of the resonance investigation: Raman and EPR spectroscopy, distribution of the functional groups inside pores can be determined. In the present article the Raman spectroscopy is treat as a complementary research to EPR investigation. It was shown that a clustering of the active groups alter significantly the resonance Raman spectra through broadening and shifts of the corresponding bands in comparison with separated molecules. Results obtained from the analysis of the resonance Raman spectra indicate significant differences between the samples prepared by the two procedures. The discussion of the Raman results was referred to EPR results, and on the base of this authors concluded about correct achievement of the functionalization.

Electronic and Resonance Raman Spectra of the Linear Chain Mixed Valence Compound Pt(NH3)2(SCN)2I

1980 ◽  
Vol 35 (10) ◽  
pp. 1272-1273 ◽  
Author(s):  
Robin J. H. Clark ◽  
Mohamedally Kurmoo ◽  
K. D. Buse ◽  
H. J. Keller
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Resonance Raman Spectroscopy ◽  
Linear Chain ◽  
Mixed Valence ◽  
Resonance Raman ◽  
Mixed Valence Compound ◽  
Resonance Raman Spectra

Abstract The partially oxidized cis-Pt(NH3)2(SCN)2I has been studied by resonance Raman spectroscopy. A progression in the symmetric I-PtIV-I vibration (v1 = 120.1 cm-1), reaching as far as 8 v1, has been observed. The compound Pt(NH3)2(SCN)2I could be identified as a mixed valence solid with neutral, linear PtII···I-PtIV chains.

Resonance Raman Spectra and Structure of Partially Oxidized Magnus' Salt

1979 ◽  
Vol 34 (7) ◽  
pp. 986-988 ◽  
Author(s):  
G. C. Papavassiliou ◽  
T. Theophanides
Keyword(s):  
Raman Spectroscopy ◽  
Quantum Number ◽  
Raman Spectra ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Chain Polymer ◽  
Resonance Raman Spectra

Abstract The partially oxidized form of Magnus' salt has been studied by resonance Raman spectroscopy (RRS) and it has been established that the oxidized form is a chlorine bridged chain polymer. The spectra show intense progressions, υν, where ν, is the symmetric ···X-Pt(IV)-X··· stretching mode, and v the quantum number

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