IR spectroscopy as a probe for C–H⋯X hydrogen bonded supramolecular synthons

CrystEngComm ◽  
2015 ◽  
Vol 17 (6) ◽  
pp. 1273-1290 ◽  
Author(s):  
Subhankar Saha ◽  
Lalit Rajput ◽  
Sumy Joseph ◽  
Manish Kumar Mishra ◽  
Somnath Ganguly ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Spectroscopic Method ◽  
Supramolecular Synthons ◽  
Ir Spectroscopic ◽  
Hydrogen Bonded

We describe a five step IR spectroscopic method that identifies supramolecular synthons in weak hydrogen bonded dimer assemblies, bifurcated systems, and π-electron mediated synthons.

AN EASY APPROACH FOR ESTIMATING ABSORPTION LOSS IN ORGANIC THIN SOLID FILMS

1999 ◽  
Vol 08 (04) ◽  
pp. 519-525
Author(s):  
SHEN YUQUAN ◽  
LI ZHAO ◽  
ZHAO YUXIA ◽  
ZHAI JIANFENG ◽  
ZHOU JIAYUN ◽  
...  
Keyword(s):  
Spectroscopic Method ◽  
Optical Loss ◽  
Polymeric Films ◽  
Absorption Loss ◽  
Optical Losses ◽  
Thin Solid Films ◽  
Solid Films ◽  
Near Ir ◽  
Ir Spectroscopic

An UV-VIS-Near-IR spectroscopic method for determination of optical loss in organic/polymeric films has been suggested. The optical losses of two polyimide polymers with push-pull azobenzene chromophore attached were examined by this method and the data were calibrated by conventional optical method.

scholarly journals Differentiation of Salmonella enterica Serovars and Strains in Cultures and Food Using Infrared Spectroscopic and Microspectroscopic Techniques Combined with Soft Independent Modeling of Class Analogy Pattern Recognition Analysis

2008 ◽  
Vol 71 (11) ◽  
pp. 2249-2256 ◽  
Author(s):  
ANNEGRET MÄNNIG ◽  
NATHAN A. BALDAUF ◽  
LUIS A. RODRIGUEZ-ROMO ◽  
AHMED E. YOUSEF ◽  
LUIS E. RODRÍGUEZ-SAONA
Keyword(s):  
Ir Spectroscopy ◽  
Disease Outbreaks ◽  
Cost Effective ◽  
Rapid Identification ◽  
Multivariate Statistical ◽  
Salmonella Serovars ◽  
Bacterial Lipopolysaccharides ◽  
Multiple Strains ◽  
Membrane Components ◽  
Ir Spectroscopic

Detection of pathogenic microorganisms in food is often a tedious and time-consuming exercise. Developing rapid and cost-effective techniques for identifying pathogens to subspecies is critical for tracking causes of foodborne disease outbreaks. The objective of this study was to develop a method for rapid identification and differentiation of Salmonella serovars and strains within these serovars through isolation on hydrophobic grid membrane filters (HGMFs), examination by infrared (IR) spectroscopy and microspectroscopy, and data analysis by multivariate statistical techniques. Salmonella serovars (Anatum, Enteritidis, Heidelberg, Kentucky, Muenchen, and Typhimurium), most of which were represented by multiple strains, were grown in tryptic soy broth (24 h at 42°C), diluted to 102 to 103 CFU/ml, and filtered using HGMFs. The membranes were incubated on Miller-Mallinson agar (24 h at 42°C), and typical Salmonella colonies were sonicated in 50% acetonitrile and centrifuged. Resulting pellets were vacuum dried on a ZnSe crystal and analyzed using IR spectroscopy. Alternatively, the membranes containing Salmonella growth were removed from the agar, vacuum dried, and colonies were analyzed directly by IR microspectroscopy. Soft independent modeling of class analogy (SIMCA) models were developed from spectra. The method was validated by analyzing Salmonella-inoculated tomato juice, eggs, milk, and chicken. Salmonella serovars exhibited distinctive and reproducible spectra in the fingerprint region (1,200 to 900 cm−1) of the IR spectrum. SIMCA permitted distinguishing Salmonella strains from each other through differences in bacterial lipopolysaccharides and other membrane components. The model correctly predicted Salmonella in foods at serovar (100%) and strain (90%) levels. Isolation of Salmonella on HGMF and selective agar followed by IR spectroscopic analysis resulted in rapid and efficient isolation, identification, and differentiation of Salmonella serovars and strains.

Determination of the composition of a copolymer of acrylonitrile with vinylimidazole by an IR-spectroscopic method

1989 ◽  
Vol 31 (9) ◽  
pp. 2211-2213 ◽  
Author(s):  
A.N. Barash ◽  
G.D. Litovchenko ◽  
N.F. Kalyanova ◽  
M.P. Zverev
Keyword(s):  
Spectroscopic Method ◽  
Ir Spectroscopic

Direct Observation of a Hydrogen-Bonded Charge-Transfer State of 4-Dimethylaminobenzonitrile in Methanol by Time-Resolved IR Spectroscopy

2003 ◽  
Vol 42 (16) ◽  
pp. 1826-1830 ◽  
Author(s):  
Wai-Ming Kwok ◽  
Michael W. George ◽  
David C. Grills ◽  
Chensheng Ma ◽  
Pavel Matousek ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Ir Spectroscopy ◽  
Direct Observation ◽  
Charge Transfer State ◽  
Time Resolved ◽  
Transfer State ◽  
Hydrogen Bonded

Acid-base properties of modified aluminas

1982 ◽  
Vol 47 (8) ◽  
pp. 2044-2060 ◽  
Author(s):  
E. A. Paukshtis ◽  
P. I. Soltanov ◽  
E. N. Yurchenko ◽  
Květa Jirátová
Keyword(s):  
Carbon Monoxide ◽  
Ir Spectroscopy ◽  
Relative Proportion ◽  
Total Acidity ◽  
Acid Base ◽  
Pure Alumina ◽  
Oh Groups ◽  
Concentration Of Ions ◽  
Ir Spectroscopic ◽  
Base Properties

Acid-base properties of the pure alumina and aluminas modified by addition of various ions were determined by IR spectroscopic and Benesi method. The quality and concentration of OH groups of alumina samples containing SO42-, F-, Cl-, Na+, Zn2+ and Mg2+ ions were determined by IR spectroscopy, Pyridine, benzonitrile and carbon monoxide were used to determine the concentration and strength of aprotic centres and deuteriochloroform was used to determine the concentration and strength of basic centres. The results allowed to evaluate changes in the above properties caused by changes in the concentration of ions in alumina. It was found that the total acidity of modified aluminas determined by Benesi method correlates well with the relative proportion of acidic OH groups in the total spectrum of OH groups.

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.

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