Infrared Spectroscopy of Solvation and Isomers in Fe+(H2O)1,2Arm Complexes

2004 ◽  
Vol 57 (12) ◽  
pp. 1145 ◽  
Author(s):  
Richard S. Walters ◽  
Michael A. Duncan
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Metal Cation ◽  
Pure Metal ◽  
Laser Vaporization ◽  
Weakly Bound ◽  
A Minor ◽  
Ion Molecule Complexes ◽  
Asymmetric Stretch ◽  
Pulsed Nozzle

Vibrational spectroscopy in the OH-stretching region is reported for the mass-selected ion–molecule complexes Fe+(H2O)Ar2 and Fe+(H2O)2Ar. These species are produced by laser vaporization in a pulsed nozzle cluster source, mass-selected with a reflectron time-of-flight mass spectrometer, and studied with infrared laser photodissociation spectroscopy. To achieve efficient photodissociation, the pure metal–water complexes are ‘tagged’ with weakly bound argon atoms. Such tagging is expected to exert a minor perturbation on the spectroscopy. However, we find that this may not be true depending on the binding site. The symmetric stretch and asymmetric stretch of water in these complexes shifts 30–50 cm−1 to the red as a result of binding to the metal cation, and an additional redshift is found for isomers with argon bound to the OH of water. The relationships between isomers and infrared spectra are discussed.

Infrared photodissociation spectroscopy of Si+(CO2)n and Si+(CO2)nAr complexes — Evidence for unanticipated intracluster reactions

2004 ◽  
Vol 82 (6) ◽  
pp. 934-946 ◽  
Author(s):  
J B Jaeger ◽  
T D Jaeger ◽  
N R Brinkmann ◽  
H F Schaefer ◽  
M A Duncan
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Laser Vaporization ◽  
Functional Theory ◽  
Size Dependent ◽  
Stretch Vibration ◽  
Ion Molecule Complexes ◽  
Small Clusters ◽  
Asymmetric Stretch ◽  
Intracluster Reactions

Si+(CO2)n and Si+(CO2)nAr ion–molecule complexes were produced by laser vaporization in a pulsed supersonic expansion. The ions were mass-selected in a reflectron time-of-flight spectrometer and studied with infrared photodissociation spectroscopy near the asymmetric stretch vibration of CO2. Si+(CO2)n clusters fragment by the loss of CO2 whereas Si+(CO2)nAr complexes fragment by the loss of argon. All clusters have resonances near the CO2 asymmetric stretch, but with shifts in frequency that are size dependent. The patterns seen in the small clusters are consistent with electrostatic bonding, while the larger systems provide evidence for an intracluster reaction forming oxide-carbonyl species. Density functional theory was employed to examine the structures of these clusters, and their calculated vibrational frequencies were compared to the measured values. Ligand assembly in Si+(CO2)n complexes is dominated by the presence of the occupied 3p valence orbital of the silicon cation. Key words: ion–molecule complexes, infrared spectroscopy, photodissociation, density functional theory.

THE INFRARED SPECTRA AND STRUCTURE OF POLYALDEHYDES: IV. THE HIGHER POLYALDEHYDES

1959 ◽  
Vol 37 (10) ◽  
pp. 1718-1721 ◽  
Author(s):  
A. Novak ◽  
E. Whalley
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectra

The polymers of n- and iso-butyraldehyde and n-valeraldehyde, which were made by subjecting the aldehydes to pressures of about 8 kb, have been examined by infrared spectroscopy. They are homologues of polyformaldehyde, having the formula HO(CHR•O)nH.

Fourier-Transform Infrared Spectroscopy of Environmentally Weathered Textile Fabrics for Enhanced Microplastic Identification

2021 ◽  
Author(s):  
Shreyas Patankar ◽  
Ekaterina Vassilenko ◽  
Mathew Watkins ◽  
Anna Posacka ◽  
Peter Ross
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Environmental Fate ◽  
Uv Light ◽  
Natural Fibers ◽  
Fourier Transform Infrared ◽  
Ambient Conditions ◽  
Selection Of

<p>Microplastic pollution in oceans is among the global environmental concerns of our time. Emerging research on ocean environments indicates that microfibers, such as those originating from textiles, are some of the most commonly occurring type of microplastic contaminants. While Fourier-transform infrared spectroscopy (FTIR) is commonly used to identify and characterize pollutant samples obtained from the environment, this identification is challenging because infrared spectra of materials can be modified by exposure to the ocean, air, UV light, and other ambient conditions, in a process referred to as “weathering”. We report preliminary efforts in improving FTIR characterization of microplastics by building a library of infrared spectra of common textile fibers weathered under a selection of ambient conditions. Consumer textile materials including polyester, nylon, cotton, and other, were exposed to a selection of ambient conditions: ocean, air, and wastewater treatment stages, in a controlled weathering experiment. Infrared spectra were monitored for up to 52 weeks, with the resulting data illuminating on the environmental fate and longevity of synthetic and natural fibers. Spectral changes caused by weathering were found to depend strongly on both the composition of the material and the specific ambient conditions. This library of weathered material spectra is useful not only in easier identification of environmental microfibers, but also in helping us estimate the duration and manner of weathering that a given environmental microfiber may have experienced.</p>

scholarly journals Influence of alkyl chain length and fluorine atoms substitution on infrared spectra of chiral liquid crystalline esters

2017 ◽  
Vol 66 (3) ◽  
pp. 63-74
Author(s):  
Anna Drzewicz ◽  
Marzena Tykarska ◽  
Magdalena Żurowska
Keyword(s):  
Molecular Structure ◽  
Infrared Spectroscopy ◽  
Liquid Crystals ◽  
Infrared Spectra ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Rigid Core ◽  
Helicoidal Structure

The infrared spectra were registered for series of three-ring liquid crystalline esters, differing in the structure of alkyl chain, in the substitution of benzene ring by fluorine atoms and in the type of helicoidal structure in the chiral smectic CA phase with antiferroelectric properties. The influence of molecular structure on the shift of signals coming from carbonyl group, located in the rigid core, was observed. Keywords: liquid crystals, helicoidal structure, chiral smectic CA phase, antiferroelectric crystalline phase, infrared spectroscopy

scholarly journals Analysis of infrared spectra of blood serum of patients with multiple myeloma

2021 ◽  
Vol 2103 (1) ◽  
pp. 012052
Author(s):  
D A Chernyshev ◽  
E S Mikhailets ◽  
E A Telnaya ◽  
L V Plotnikova ◽  
A D Garifullin ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Principal Component Analysis ◽  
Infrared Spectroscopy ◽  
Blood Serum ◽  
Infrared Spectra ◽  
Early Stage ◽  
Principal Component ◽  
Healthy Donors ◽  
Components Analysis ◽  
Serious Disease

Abstract Multiple myeloma (MM) is a serious disease that is difficult to diagnose especially at early stage. Infrared spectroscopy is a promising approach for diagnosing MM. The principal component analysis (PCA) allows us to reduce the dimension of the data and keep only the important variables. In this study, we apply principal components analysis to infrared (IR) spectra of blood serum from healthy donors and multiple myeloma patients. As a result of the analysis by PCA, it was possible to visualize the separation of patient’s and donor’s samples into two clusters. The result indicates that this method is potentially applicable for diagnosis of multiple myeloma.

Spectral Interpretation and Qualitative Analysis of Organophosphorus Pesticides Using FT-Raman and FT-Infrared Spectroscopy

1996 ◽  
Vol 50 (5) ◽  
pp. 565-571 ◽  
Author(s):  
Peter A. Tanner ◽  
Kim-Hung Leung
Keyword(s):  
Raman Spectroscopy ◽  
Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Temperature Effects ◽  
Organophosphorus Pesticides ◽  
Spectral Interpretation ◽  
Ft Raman Spectroscopy ◽  
Safe Technique ◽  
Characteristic Group ◽  
Ft Raman

FT-Raman spectroscopy is a selective and safe technique for the qualitative identification of organophosphorus pesticides and is not accompanied by sample photodecomposition. Spectra of 14 target pesticides were recorded, and the phosphorus characteristic group frequencies are discussed. Preliminary investigations of solvent and temperature effects upon the infrared spectra were also carried out.

How many cells are enough for single-cell infrared spectroscopy?

2020 ◽  
Vol 56 (26) ◽  
pp. 3773-3776 ◽  
Author(s):  
Yadi Wang ◽  
Wentao Dai ◽  
Yue Wang ◽  
Jixiang Liu ◽  
Zhixiao Liu ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Single Cell ◽  
Infrared Spectra ◽  
Similarity Distance

The similarity distance among single-cell infrared spectra reveals that at least 15 cells are required to achieve robust results with 95% confidence.

scholarly journals Infrared Spectroscopy of Gas-Phase M+(CO2)n (M = Co, Rh, Ir) Ion–Molecule Complexes

2017 ◽  
Vol 121 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Andreas Iskra ◽  
Alexander S. Gentleman ◽  
Aras Kartouzian ◽  
Michael J. Kent ◽  
Alastair P. Sharp ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Gas Phase ◽  
Ion Molecule Complexes
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