scholarly journals Polymorphism of hydrogen-bonded star mesogens – a combinatorial DFT-D and FT-IR spectroscopy study

RSC Advances ◽  
2019 ◽  
Vol 9 (15) ◽  
pp. 8444-8453 ◽  
Author(s):  
Michael Pfletscher ◽  
Janek Wysoglad ◽  
Jochen S. Gutmann ◽  
Michael Giese
Keyword(s):  
Infrared Spectroscopy ◽  
Ir Spectroscopy ◽  
Quantum Chemistry ◽  
Spectroscopy Study ◽  
Ft Ir ◽  
Ft Ir Spectroscopy ◽  
Hydrogen Bonded

The structure of hydrogen-bonded star mesogens is investigated using modern quantum chemistry methods in combination with infrared spectroscopy.

The Hydrogen-Bonded 2-Pyridone Dimer Model System. 1. Combined NMR and FT-IR Spectroscopy Study

2010 ◽  
Vol 114 (29) ◽  
pp. 7749-7760 ◽  
Author(s):  
Łukasz Szyc ◽  
Jing Guo ◽  
Ming Yang ◽  
Jens Dreyer ◽  
Peter M. Tolstoy ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Model System ◽  
Spectroscopy Study ◽  
Dimer Model ◽  
Ft Ir ◽  
System 1 ◽  
Ft Ir Spectroscopy ◽  
Hydrogen Bonded

Protein secondary structure from FT-IR spectroscopy: correlation with dihedral angles from three-dimensional Ramachandran plots

1991 ◽  
Vol 69 (11) ◽  
pp. 1639-1642 ◽  
Author(s):  
Michael Jackson ◽  
Henry H. Mantsch
Keyword(s):  
Ir Spectroscopy ◽  
Three Dimensional ◽  
Protein Secondary Structure ◽  
Secondary Structures ◽  
Dihedral Angles ◽  
Carbonyl Groups ◽  
Amide Carbonyl ◽  
Ft Ir ◽  
Ft Ir Spectroscopy ◽  
Hydrogen Bonded

The frequency of the so-called "amide I" band (amide C=O stretching vibration, vC=O) of proteins is discussed in terms of the dihedral angles of the various secondary structures present within proteins. We propose that in the case of intra- or intermolecular hydrogen-bonded amide carbonyl groups the frequency of this absorption can be directly related to the [Formula: see text], ψ angles of the amide moieties for the major secondary structures. Amide I bands at frequencies above those found for non-hydrogen bonded amide carbonyl groups are rationalized in terms of a change in the third dihedral angle, ω. Rotation around the amide C—N bond in sterically demanding structures, such as turns where ω deviates from 180°, is expected to cause an increase in the electron density of the amide carbonyl groups and so increase vC=O to frequencies greater than that seen for unperturbed carbonyl groups. Key words: FT-IR spectroscopy, proteins, structure, dihedral angles.

scholarly journals Classification of Five Kinds of Moss Plants with the Use of Fourier Transform Infrared Spectroscopy and Chemometrics

2011 ◽  
Vol 25 (6) ◽  
pp. 271-285 ◽  
Author(s):  
Tao Hu ◽  
Wen-Ying Jin ◽  
Cun-Gui Cheng
Keyword(s):  
Cluster Analysis ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ir Spectroscopy ◽  
Ir Spectra ◽  
Fourier Transform Infrared Spectroscopy ◽  
Moss Species ◽  
Ft Ir ◽  
And Cluster Analysis ◽  
Ft Ir Spectroscopy

Fourier transform infrared spectroscopy (FT-IR) with Horizontal Attenuated Total Reflectance (HATR) techniques is used to obtain the FT-IR spectra of five kinds of mosses, such asPtychomitrium dentatum(Mitt.) Jaeg.,Ptychomitrium polyphylloides(C. Muell.) Par.,Ptychomitrium sinense(Mitt.) Jaeg.,Macromitrium syntrichophyllumTher. Etp. Vard., andMacromitrium ferrieiCard. Sz Ther. Based on the comparison of the above mosses in the FT-IR spectra, the region ranging from 4000 to 650 cm−1was selected as the characteristic spectra for analysis. Principal component analysis (PCA) and cluster analysis are considered to identify the five moss species. Because they belong to the homogeneous plants, and have similar chemical components and close FT-IR spectroscopy, PCA and cluster analysis can only give a rough result of classification among the five moss species, Fourier self-deconvolution (FSD) and discrete wavelet transform (DWT) methods are used to enhance the differences between them. We use these methods for further study. Results show that it is an excellent method to use FT-IR spectroscopy combined with FSD and DWT to classify the different species in the same family. FT-IR spectroscopy combined with chemometrics, such as FSD and DWT, can be used as an effective tool in systematic research of bryophytes.

Temperature-Dependent FT-IR Spectroscopy Study of Silver 1,9-Nonanedithiolate

2001 ◽  
Vol 55 (8) ◽  
pp. 1085-1091 ◽  
Author(s):  
Hyouk Jin Choi ◽  
Sang Woo Han ◽  
Seung Joon Lee ◽  
Kwan Kim
Keyword(s):  
Ir Spectroscopy ◽  
Spectroscopy Study ◽  
Temperature Dependent ◽  
Ft Ir ◽  
Ft Ir Spectroscopy
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