Facilities: Optical Spectroscopy Instrumentation

 

Infrared Spectroscopy

The amount of energy a molecule contains is not continuously variable but quantized. This means that a molecule can stretch, bend, or rotate only at specific frequencies. For example, a typical C-H bond has an average bond length of 1.10 Angstroms. This length is only an average – vibrating back and forth due to stretching, bending, and rotation (both symmetrically and asymmetrically) are all happening on a moment by moment basis.
 

 
When the molecule is irradiated with electromagnetic radiation, the vibrating bond will absorb energy if the frequencies of the light and the vibration are the same. This absorption phenomena is the principle the IR takes advantage of in the production of spectra that can be easily interpreted by the trained chemist.
 
 

 
The above graph, of an unknown sample, shows specific regions where the vibrations are characterized. The IR is a popular tool used by inorganic, organic, and physical chemists due to the variety of information it conveys in a fast amount of time.
 

 


 
Nicolet iS5 FTIR (2015)
 

 
Nicolet 380 FTIR (2006)
 
Contact Information:
 
Dr. Michael Norton
Dept. of Chemistry
Email: norton@marshall.edu
Phone: (304) 696-3489
 
Dr. Gary Anderson
Dept. of Chemistry
Email: anderson@marshall.edu
Phone: (304) 696-6594
 
Dr. Michael Castellani
Dept. of Chemistry
Email: castella@marshall.edu
Phone: (304) 696-6486

 

 
Nicolet iS50 FTIR with Smart Diffuse Reflectance (2014)
 
Contact Information:
 
Dr. Rosalynn Quinones
Dept. of Chemistry
Email: quinonesr@marshall.edu
Phone: (304) 696-6731

 

 
Matrix Isolation FTIR: Bruker FTIR with pyrolysis unit and cryostat cell (2009)
 
Contact Information:
 
Dr. Laura McCunn
Dept. of Chemistry
Email: mccunn@marshall.edu
Phone: (304) 696-2319

 

 
Bruker Optics Vertex 70 FTIR Spectrometer (2008)
 
Contact Information:
 
Dr. Laura McCunn
Dept. of Chemistry
Email: mccunn@marshall.edu
Phone: (304) 696-2319

 

UV/Vis Spectroscopy

Ultraviolet spectroscopy is applicable solely to conjugated systems. This is because most organic compounds produce no effect whenever the relatively high-energy radiation that constitutes the ultraviolet (200–400 nm) and visible (400–700 nm) portion of the electromagnetic spectrum are presented. Whenever ultraviolet radiation is used, the energy absorbed by a molecule corresponds to the amount necessary to excite electrons from one molecular orbital to another. Typical organic compounds, which mostly contain s bonds, require much higher wavelengths to become excited than what the range of UV will provide. Only those conjugated systems with a number of p bonds are capable of being promoted to higher energy levels by ultraviolet and visible light.

A sample is placed into a cuvette and the spectrum is recorded by irradiating the sample with ultraviolet light of continuously changing wavelength. When the wavelength of light corresponds to the energy level required to excite an electron to a higher energy level, energy is absorbed. This absorption is detected and plotted on the vertical axis as the absorption while the wavelength of the absorbed light is plotted horizontally.


Visit San Diego State University for a primer on UV/Vis Spectroscopy


 

 
2 Cary 50 Bio UV-VIS Spectrophotometers (2006)
 
Contact Information:
 
Dr. Michael Norton
Dept. of Chemistry
Email: norton@marshall.edu
Phone: (304) 696-3489
 
Dr. William Price
Dept. of Chemistry
Email: pricew@marshall.edu
Phone: (304) 696-3156

 

 
GE NanoVue UV/Vis Spectrophotometer (2008)
 
Contact Information:
 
Dr. Bin Wang
Dept. of Chemistry
Email: wangb@marshall.edu
Phone: (304) 696-3456

 

 
Shimadzu UV-1800 UV/Vis Spectrophotometer (2009)
 
Contact Information:
 
Dr. Derrick Kolling
Dept. of Chemistry
Email: kolling@marshall.edu
Phone: (304) 696-2307

 

 
BioTek Epoch Microplate Spectrophotometer (2009)
 
Contact Information:
 
Dr. Kenneth O’Connor
Dept. of Chemistry
Email: oconnor9@marshall.edu
Phone: (304) 696-4358

 

Atomic Absorption Spectroscopy


 
Varian SpectrAA-600 AAS with a GTA-100 Zeeman Graphite Furnace (1994)
 
Contact Information:
 
Dr. Aley El-Shazly
Dept. of Geology
Email: elshazly@marshall.edu
Phone: (304) 696-6756

 

Atomic Emission Spectroscopy


 
Varian Liberty 110 ICP-AES (1994)
 
Contact Information:
 
Dr. Aley El-Shazly
Dept. of Geology
Email: elshazly@marshall.edu
Phone: (304) 696-6756

 

Fluorescence Spectroscopy


 
SPEX Fluorolog III lifetime fluorometer (1998)
 
Contact Information:
 
Dr. Robert Morgan
Dept. of Chemistry
Email: morganr@marshall.edu
Phone: (304) 696-3159

 

 
ISS PC1 Photom Counting Spectrofluorometer (1998)
 
Contact Information:
 
Dr. Michael Norton
Dept. of Chemistry
Email: norton@marshall.edu
Phone: (304) 696-3489

 

 
PerkinElmer LS 55 Fluorescence Spectrometer (2009)
 
Contact Information:
 
Dr. Bin Wang
Dept. of Chemistry
Email: wangb@marshall.edu
Phone: (304) 696-3456

 

 
Photon Systems Instruments FL 3500 Fluorometer (2009)
 
Contact Information:
 
Dr. Derrick Kolling
Dept. of Chemistry
Email: kolling@marshall.edu
Phone: (304) 696-2307

 

Circular Dichroism Spectroscopy

Circular dichroism spectroscopy is used to gain information about the secondary structure of proteins and polypeptides in solution. It is a form of light absorption spectroscopy measuring the differences between matter absorbing right and left-hand circularly polarized light slightly differently. This is especially important when examining proteins because only those proteins with the correct conformation will function properly.
 
The difference in absorbance between right and left-handed molecules is only a few 1/100th of a degree at the far UV wavelengths of 190-170 nm. A major benefit of the CD is it uses a very small amount of the sample (200ul of 0.5 mg/ml solution in standard cells) and is even non-destructive with that portion, so the small biological samples that are either extracted or synthesized can effectively be reused in other tests.
 

 
OLIS DSM-CD Circular Dichroism spectrophotometer w/ dual beam absorption and total fluorescence capabilities (1999)
 
Contact Information:
 
Dr. Michael Norton
Dept. of Chemistry
Email: norton@marshall.edu
Phone: (304) 696-3489
 
Dr. Robert Morgan
Dept. of Chemistry
Email: morganr@marshall.edu
Phone: (304) 696-3159
 
Dr. Leslie Frost
Dept. of Chemistry
Email: frost@marshall.edu
Phone: (304) 696-6774
 
Dr. William Price
Dept. of Chemistry
Email: pricew@marshall.edu
Phone: (304) 696-3156