Experimental and Computation Vibration-Rotation Spectroscopy for Carbon Monoxide Through the Use of High-Resolution Infrared (IR) Spectra
Introduction: The goal of this experiment is to study the most precise way of measuring molecular bond lengths and introduction to computational software used for studying molecular properties. This is of interest in that the instrument to being used, a Fourier-transform infrared (FT-IR) spectrometer, can measure the vibrational and rotational transitions of the fundamental and first overtone of CO. Through this experiment the objective is to collect data from the aforementioned instrument in order to determine vibrational and rotational spectroscopic constants and CO’s bond length, then to compare
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- Example calculation for the determination of values for Be and e.
- Example calculation for the determination of values for e and exe. - Example calculation for the determination of values for Ie, Io, I1, and I2. - Example calculation for the determination of values for re, r0, r1, and r2. - Conversion of units from GHz to cm-1 for Be
- Error analysis obtained through Table Curve was base on the fitting of equation 2040 in their data base ( ), this gave direct values for the vo quantities and De was obtained by taking an average of the “d” constants divided by 4 from the relating equation - Error analysis of Bo, B1, and B2 is also based on values coming from Table Curve will error being the same for all of them. - Error analysis of Be and
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For this reason it is such that very little could be done to correct error within this experiment other than to upgrade and ensure proper maintenance of the equipment and apparatus. For the main part the error comes from the non-ideal behavior of the CO in response to the stretching of its triple bond. As opposed to the situation of the rigid rotor, when an actual molecule is stretched to a certain point the bond disintegrates rather than following the ideal path. It seems that for the most part the calculated values measured up fairly well when compared to those in the literature, in some cases better than the Gaussian 98’ computer program’s values. This is due to the fact that the computer program has values that follow specific criteria, and under real circumstance the behavior of a molecule doesn’t always follow this assumed path. The error determined by the error analysis for B which effected following values was of some concern, however this could be alleviated by choosing a better fitting equation for the data with regards to both sets of data. With this in mind the outcome of the experiment is satisfactory as far as calculated values and gained experience is
The complete experimental procedure is available in the General Chemistry Laboratory Manual for CSU Bakersfield, CHEM 213, pages 20-22, 24-25. Experimental data are recorded on the attached data pages.
Fig 1: Applications of single molecule spectroscopy in solving scientific problems in Physics, Chemistry and Biology
[9] 2009, “CRC Handbook of Chemistry and Physics, 90th edition,” American Chemical Society CNC Press, Boca Raton, pp. 631-637
Michael P. Broadribb, C. (2006). Institution of Chemical Engineers . Retrieved July 26, 2010, from IChemE: http://cms.icheme.org/mainwebsite/resources/document/lpb192pg003.pdf
In infrared (IR) spectroscopy, infrared light interacts with molecules of the substance. The collected data is used to determine the substance. Infrared light is a part of the electromagnetic spectrum and contains longer wavelengths than visible light. In this type of spectroscopy, an IR beam passes through the sample substance. Consequently, the covalent bonds absorbs the beam, thus this causes a change in the vibrations of the dipole moment in the substance. This spectroscopy is primarily used in organic and inorganic chemistry in order to determine the functional groups in the substance, as various functional groups have specific vibrations when absorbing the IR beam.
In this experiment, we computationally predicted the dipole moments of 5 different analyte molecules using the program Spartan. We constructed the molecules online as the program then calculated their dipole moments (polarity). We then experimentally determined the 5 analyte molecules retention factors using the TLC method in the lab. Polarity in organic chemistry refers to a separation of electric charge leading to a molecule having an electric dipole moment1. To determine whether a molecule is polar or nonpolar depends on a molecules structure. This is done by comparing the electronegativity’s of each element in the molecule that are bonded to each other. If a molecules dipole moment eliminates each other due to its symmetrical shape, it is considered to be
Neidig, H. A., and J. N. Spencer. "Precipitating Lead Chromate on a Small Scale." General Chemistry For Engineering And Science. Mason: Cengage Learning, 2012. 83-90. Print. Signature Lab Ser.
Polman, H., Orobio De Castro, B. & Van Aken, M. A.G. (2008). Experimental Study of the
The Cartoon Guide to Chemistry by Larry Gonick and Craig Criddle is a non-fiction book that utilizes visual images and cartoons to cover the basics and intricacies of Chemistry. It consists of two-hundred and fifty-six pages and was published by Collins Reference on May 3, 2005. It covers topics such as chemicals reactions, solutions, acid basis, and chemical thermodynamics in unique fashion that makes chemistry fun and easy to learn as well as understand. The book has no consistent build up or story to it. It simply moves from chemistry subject A to chemistry subject B, explaining the various components that make up the subject of chemistry.
VMD can be useful to a range of audience, molecular structural data obtained from VMD can be integrated with bioinformatics, which will then provide useful information to researchers of biological system, not only individuals involved with the field of biological science, but also theoretical and experimental researchers of chemical science can utilize the information to scrutinize the chemical structure of molecules. It can also be used in educational institutions to display molecules in a very descriptive manner to students, to give them a broader idea of the structural function.
Not knowing how to calculate the molecular formulas, and not even knowing what molecular formulas are for that matter, proved to be a challenging obstacle for Lavoisier to overcome. Once it was proved that compound atoms had fixed and definite compositions, the first molecular formulas emerged. Oddly, it was John Dalton, a physicist, who discovered the first molecular formulas (Salzberg, 209). Dalton did this by calculating atomic weights through selective interatomic repulsions, and from these repulsions he derived the first molecular formulas. Although it is odd that a physicist derived the formulas used in chemistry, this shows how empirical and molecular formulas have always been necessary in all the
" Carbon is used in diamonds, petroleum oil, radiocarbon dating, smoke detectors, kerosine, gasoline, carbon fiber. Alcin is a member of the Council of the United States. Organic chemistry is the study of carbon and its compounds (Alcin). Carbon is less than one percent of all matter. Carbon is part of every living thing (Gangson).
de Beer, FC. du Plessis, MM. Liebenberg, A & Moloi,R. 2005. Only study guide for DVA 202-U. Pretoria: University of South Africa
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
Please choose one of the molecules that we learned about in the readings, and describe it.