JSPM’s

Charak College of Pharmacy& Research Gat No. 720/1&2, Wagholi, Pune-Nagar Road, Pune- 412 207.

A Seminar on Chemical Application of Spectroscopic Method

Presented By Guided by Mr. Pradeep V. Kore DR. Rajesh J Oswal

Prof. Sandip Kshirsagar

Department Of Pharmaceutical Chemistry

Introduction: Spectroscopy

• It is the study of the interaction between matter and radiated energy.

• Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism.

• Later the concept was expanded greatly to comprise any interaction with radiative energy as a function of its wavelength or frequency.

• Spectroscopic data is often represented by a spectrum, a plot of the response of interest as a function of wavelength or frequency.

1.Chemical Application of Spectroscopic method in Bioinorganic Chemistry : Blue to Green to Red

.This presentation will summarize the contributions of a range of spectroscopic methods combined with calculations in elucidating the electronic structure of an active site using the blue copper site as an example.

The contribution of electronic structure to electron-transfer reactivity will be considered in terms of anisotropic covalency, electron-transfer pathways, reorganization energy, and protein contributions to the geometric and electronic structures of blue-copper-related active sites.

2. Chromatographic and spectroscopic methods for the determination of solvent properties of room temperature ionic liquids.

Chromatographic and spectroscopic methods afford suitable tools for the study of solvation properties under conditions that approximate infinite dilution.

Gas–liquid chromatography is suitable for the determination of gas–liquid partition coefficients and activity coefficients as well as thermodynamic constants .

The solvation parameter model can be used to define the contribution from individual intermolecular interactions to the gas–liquid partition coefficient.

Application of chemometric procedures to a large database of system constants for ionic liquids indicates their unique solvent properties:

low cohesion for ionic liquids with weakly associated ions compared with non-ionic liquids of similar polarity.

greater hydrogen-bond basicity than typical polar non-ionic solvents.

a range of dipolarity/polarizability that encompasses the same range as occupied by the most polar non-ionic liquids.

3 Application of laser spectroscopic methods for in vivo dignostic in dermatology

The importance of dermatologic non-invasive imaging techniques has increased over the last decades.

Technich provide a preservation of the tissue's physical

structure while being studied in its native state.

Different modalities are currently being used to investigate the skin tissue.

Many of these scanning instruments are still undergoing research for the diagnostic in dermatology

Some imaging techniques:

1.High-resolution ultrasonography,

2.optical coherence tomography

3.Magnetic resonance imaging

4.Spectroscopic methods, find a role in dermatologic diagnosis and disease monitoring.

• 4.Application of Spectroscopic Methods for Structural analysis of chitin & chitosan. Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry.

• Two of the main reasons for this wide range application :

• 1.The unique chemical, physicochemical and biological properties of chitin and chitosan,

• 2.unlimited supply of raw materials for their production.

• These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production.

• The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications.

X-ray spectroscopy for structural analysis of chitin

• X-ray spectroscopy is unarguably the most versatile and widely used means of characterizing materials of all forms .

• There are two general types of structural information that can be studied by X-ray spectroscopy: 1.Electronic structure (focused on valence and core electrons, which control the chemical and physical properties, among others) 2.Geometric structure (which gives information about the locations of all or a set of atoms in a molecule at an atomic resolution).

Infrared spectroscopy for analysis of chitin & chitosan.

• Infrared (IR) spectroscopy is one of the most important and widely used analytical techniques available to scientists working on chitin and chitosan.

• It is based on the vibrations of the atoms of a molecule.

• The infrared spectrum is commonly obtained by passing infrared electromagnetic radiation through a sample that possesses a permanent or induced dipole moment and determining what fraction of the incident radiation is absorbed at a particular energy.

• The energy of each peak in an absorption spectrum corresponds to the frequency of the vibration of a molecule part, thus allowing qualitative identification of certain bond types in the sample.

5.Spectroscopic Methods in Industrial Chemistry 1) The use of spectroscopic techniques

for the bulk-characterization of heterogeneous catalysts:a)    X-ray diffraction (powder method and single-crystal method), for the identification of crystalline phases. Methods for the qualitative and quantitative determination of phases in complex matrixes. Characterization of metal, oxides, salts. In-situ techniques for the study of structural modifications occurring during reaction: thermal cells, environment cells. b)      Raman spectroscopy, and its use for the identification of vibrations characteristic of specific catalysts and compounds. In-situ evolution under conditions simulating those of catalytic application.

c)      Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Force Microscopy, Tunnelling Microscopy and related techniques for the identification of active surface nature, and of components. Use of electronic probes for the quantitative determination of elements.

d)      EXAFS, NEXAS, and related high-energy techniques, for the study of the short-range environment of components.

e)      Mossbauer spectroscopy, X-ray fluorescence, and other techniques of investigation.

2) The use of spectroscopic techniques for the surface-characterization of heterogeneous catalysts.

a)      UV-Vis Diffuse Reflectance Spectroscopy, for the identification of surface active sites, their coordination environment, and their valence state. In-situ techniques for the identification of the nature of active sites under reactive conditions.

b)     FT-IR spectroscopy for the identification of the nature of reactive intermediates, and of the interaction between reactants and catalyst surface. Surface characterization of active sites. In-situ cells for the study of catalytic surfaces under conditions simulating the reaction.

c)      X-ray photoelectron spectroscopy, for the identification of the relative amount and nature of surface active sites.

• 6.surface analysis tech. by spectroscopic methods. In analytical chemistry, the study of that part of a solid that is in contact with a gas or a vacuum.

• When two phases of matter are in contact, they form an interface.

• The term surface is usually reserved for thin interface between a solid and a gas or between a solid and a vacuum; the surface is considered to be that part of the solid that interacts with its environment.

• Other interfaces—those between two solids, two liquids, a solid and a liquid, or a liquid and a gas—are studied separately.

spectroscopic tech for structural analysis

Spectroscopic techniques function through a “beam in, beam out” mechanism.

• A beam of photons, electrons, or ions impinges on a material and penetrates to a depth that is dependent on the beam characteristics.

• A second beam, resulting from the interaction of the first beam with the solid, exits from the surface and is analyzed by a spectrometer.

• The exiting beam carries with it information regarding the composition of the material with which the beam interacted. By varying both the type of particle and the energy of the entering beam, one can generate a large number of surface analytical techniques.

For a surface analytical technique, the information obtained by the spectrometer from the exiting beam should be characteristic of that region of the solid that is defined as the surface. Either the penetration depth of the incident beam, the escape depth of the exiting beam, or both therefore must be limited to the thickness of the surface.

7.Recent Progress in Application of Spectroscopic Methods for Assigning Absolute Configuration of Optically Active Sulfoxides

• In the recent years, in addition to the more traditional methods based on X-ray diffraction and mechanistic considerations, the problem of the configurational assignment of optically active sulfoxides has been approached with spectroscopic methods. • In this review the methods based on the use of NMR spectroscopy and electronic circular dichroism are described, as well as the emerging approaches based on the analysis of vibrational CD spectra, on the ab initio calculation of the optical rotation and on the cholesteric induction in nematic solvents.

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