Matrix isolation study of the photochemically induced reaction of ozone with dibromochloromethane and bromodichloromethane in solid argon at 14 K. FT-IR spectra of the complexes C(O)HCl  · · ·  BrX, C(O)HBr  · · ·  XCl, C(O)BrCl  · · ·  HX, (OC)(HCl)(Br2), (OC)(HBr)(Cl2), and (OC)(BrCl)(HX) (where X = Br or Cl)

1999 ◽  
pp. 73-78 ◽  
Author(s):  
Robin J. H. Clark ◽  
Jonathan R. Dann ◽  
Loraine J. Foley
Keyword(s):  
Ir Spectra ◽  
Matrix Isolation ◽  
Ft Ir ◽  
Solid Argon ◽  
Induced Reaction

2-Chloroallyl Cation. Structure, FT-IR Spectra, and Matrix Isolation

1999 ◽  
Vol 64 (13) ◽  
pp. 4931-4934 ◽  
Author(s):  
Davor Kiđemet ◽  
Zlatko Mihalić ◽  
Igor Novak ◽  
Hrvoj Vančik
Keyword(s):  
Ir Spectra ◽  
Matrix Isolation ◽  
Ft Ir

scholarly journals Matrix-isolation FT-IR spectra and theoretical study of dimethyl sulfate

2005 ◽  
Vol 61 (7) ◽  
pp. 1461-1470 ◽  
Author(s):  
Ana Borba ◽  
Andrea Gómez-Zavaglia ◽  
Pedro N.N.L. Simões ◽  
Rui Fausto
Keyword(s):  
Ir Spectra ◽  
Theoretical Study ◽  
Matrix Isolation ◽  
Dimethyl Sulfate ◽  
Ft Ir

Examinations of the Matrix Isolation Infrared Spectra of Organic Compounds: PART XIII

1989 ◽  
Vol 43 (2) ◽  
pp. 305-310 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon
Keyword(s):  
Ir Spectra ◽  
Organic Compounds ◽  
Matrix Isolation ◽  
Intramolecular Hydrogen Bonding ◽  
Double Bond Position ◽  
Absorption Bands ◽  
The Matrix ◽  
Carbon Substitution ◽  
Ft Ir ◽  
Intramolecular Hydrogen

Matrix isolation Fourier transform infrared (MI/FT-IR) spectra have been collected on a series of internal alkenes, a series of hydroxy-substituted ketones, and a series of hydroxy-substituted esters. Assignments of double bond position and geometry are possible in the alkenes, due to the resolution of absorption bands of very similar energies. The location of the absorption bands for the alkenes was found to be very similar to the values found for the vapor-phase and condensed-phase spectra. Multiple carbonyl absorptions have been found in the MI/FT-IR spectra of the hydroxy ketones and hydroxy esters. Trends in the multiplicity of the carbonyl absorption patterns for these compounds as a function of ring size and hydroxyl carbon substitution have been used to document the presence of extensive intramolecular hydrogen bonding. The argon matrix as a phase for the study of stable organic compounds has, again, with this information, been shown to be unique.

Examinations of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part XII

1989 ◽  
Vol 43 (2) ◽  
pp. 298-304 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon ◽  
Brian M. Lawrence
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Infrared Spectra ◽  
Matrix Isolation ◽  
Fourier Transform Infrared ◽  
Fourier Transform Infrared Spectra ◽  
The Matrix ◽  
Ft Ir ◽  
Nanogram Level ◽  
C Nmr

Matrix isolation Fourier transform infrared spectra (MI/FT-IR), mass spectra (MS), carbon-13 Nuclear Magnetic Resonance (13C-NMR) spectra, condensed-phase infrared spectra, and vapor-phase infrared (IR) spectra are presented for a series of terpene compounds. Subtle differences in positional and configurational isomers commonly found with terpenes could be easily detected by the MI/FT-IR spectra. The results are comparable in some aspects to those obtainable from 13C-NMR and thin-film IR; however, most importantly, they are acquired at the low nanogram level for MI/FT-IR, as compared to the milligram level for the other techniques. These results represent an advance in the technology available for the analysis of complex mixtures such as essential oils containing terpene-like molecules.

Light- or Dark-Colored, L-DOPA-Based Melanins

2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Margaret M. Whalen
Keyword(s):  
Human Physiology ◽  
Ir Spectra ◽  
Immune Cells ◽  
Chemical Properties ◽  
Chemical Signature ◽  
Ft Ir

<p>This report is a continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub> </sub>oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.</p>

scholarly journals Spectroscopy as a useful tool for the identification of changes with time in post-mortem vitreous humor for forensic toxicology purposes

2021 ◽  
Author(s):  
Anna Wójtowicz ◽  
Agata Mitura ◽  
Renata Wietecha-Posłuszny ◽  
Rafał Kurczab ◽  
Marcin Zawadzki
Keyword(s):  
Ir Spectra ◽  
Forensic Toxicology ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Vitreous Humor ◽  
Attenuated Total Reflection ◽  
Glass Slides ◽  
Added Benefit ◽  
Ft Ir ◽  
Non Destructive

AbstractVitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3. Graphic abstract

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