Info about the IR spectroscopy instrument

           Different regions of an IR spectrum corresponding with the various bond vibrations, such as the broad peak before the 3000  is an indicative for the O-H stretching. By using the isotopic substitution to determine the at which frequencies, which bond is vibrate. Interchanging one of an atoms participating in bond with its isotope shifts a frequency of bond vibration in a predictable way. Such as In the O-H group of alcohol its isotopes substitute the hydrogen bond, deuterium (D), stretching frequency of this O-D bond will be shifted with respect to an original O-H bond. The reason why these shifts occur has to do with the fact that chemical bonds act like springs.

            A spring oscillates in a harmonic motion as the spring is displaced from its equilibrium position. Therefore, a simple harmonic oscillator that obeys Hooke’s Law can model a bond between two atoms. The exact frequency at which a given vibration occurs is determined by the strengths of the bonds involved and the mass of the component atoms. For a more detailed discussion of these factors. In practice, infrared spectra do not normally display separate absorption signals for each of the 3n-6 fundamental vibrational modes of a molecule.

Experimental Procedure of Info about the IR spectroscopy instrument

            There are lab instruments that produce infrared rays for experimental analysis. A beam of infrared light, of a particular wavelength, is produced, and the light wave is split into two separate beams. One of the beams is passed through the sample for analysis, the other passed through a reference substance, in which is often the solvent substance where the sample is dissolved in. The beams are then both reflected back to a detector, in this step, however, first the beams pass through a splitter that alternates quickly which between the two beams enters the detector. The two signals are compared, and a printout is obtained.

A reference is used for two reasons:

The reference prevents fluctuations in the output of the source affecting the data

It allows the effects of the solvent to be canceled out (a reference is usually a pure form of the solvent the sample is in)

Reagents used:

Acetone

Acetone-d6

Methanol

Methanol

Methanol-d

Methanol-d

Benzene

Benzene-d

DAMSON

DAMSON-d

Acetonic

Acetonic-d3

This experiment will involve the use of liquid phase FT-IR. When handling with the salts plate always use the gloves, along with only clean plates by hexanes or heptane

The spectra were be recorded for:

1) benzene and deuterated benzene

2) acetone and deuterated acetone

3) acetonitrile and deuterated acetonitrile

4) dimethyl sulfoxide (DMSO) and deuterated dimethyl sulfoxide

5) Methanol and deuterated methanol

A few drops of the solvent were placed onto the diamond crystal. The arm was twisted into place until a click was heard, and the IR was run. The procedure was repeated for the deuterated solvent, and the diamond surface was rinsed with acetone after each use.

Results of Info about the IR spectroscopy instrument

Analysis of the Bonds

C=S thiocarbonyl        1050-1200 (str)

S=O sulfoxide             1030-1060 (str)

Sulfone                        1325± 25 (as) & 1140± 20 (s) (both str)

Sulfonic acid               1345 (str)

sulfonyl chloride         1365± 5 (as) & 1180± 10 (s) (both str)

Sulfate                         1350-1450 (str)

O-H (stretch)               3550-3600 cm-1(str)

C=N                            1665± 15

N-O                             945± 15

Aliphatic                     960± 20

Aromatic                     1250± 50

N=O:

Nitroso                        1550± 50 (str)

Nitro                            1530± 20 (as) & 1350± 30 (s)

Stretching frequencies of Info about the IR spectroscopy instrument

C–H stretch from 3000–2850 cm-1

C–H bend or scissoring from 1470-1450 cm-1

C–H rock, methyl from 1370-1350 cm-1

C–H rock, methyl, seen only in long chain alkanes, from 725-720 cm-1

C=C stretch from 1680-1640 cm-1

=C–H stretch from 3100-3000 cm-1

=C–H bend from 1000-650 cm-1

O–H stretch, hydrogen bonded 3500-3200 cm-1

C–O stretch 1260-1050 cm-1

C=O stretch:

aliphatic ketones 1715 cm-1

α, β-unsaturated ketones 1685-1666 cm-1

O–H stretch from 3300-2500 cm-1

C=O stretch from 1760-1690 cm-1

C–O stretch from 1320-1210 cm-1

O–H bend from 1440-1395 and 950-910 cm-1

Acetone D and Acetone P

            The FT-IR method for the isotopes ratio analysis is verified through the acetone D, along with the acetone P. The above graph is between the wavenumber along with absorbance. The spectra of the acetone D recorded from to  by using the scan of . In addition, in the acetone P spectra recorded from to  by using the scan of. In general, the acetone D shows the isotopic shifts about the expected shifts at 1000 to 2000 for the Acetone P. there are few spectra that is recorded by the acetone samples along with the substrate rotated for the 1K to 4K regarding to the axis pre to the IR beam.

Acetonitrile P and Acetonitrile D

The IR spectrum for the Acetonitrile is used in the studied of the IR peaks, where the Acetonitrile brought the interaction between an Acetonitrile molecule as well as ions electrolyte. The above graph of the Acetonitrile P along with the Acetonitrile D is between t

wavenumber as well as transmittances. The IR spectra of Acetonitrile containing the molecules of the P and D Acetonitrile electrolyse. These spectra are obtained from the original data, which is collected and present the Acetonitrile P and D. The bottom trace of Acetonitrile D shows the value of wavenumber  which strongly dominate the spectrum about the absorbance regions

Benzene P & Benzene D \

        In the Benzene P the aromatic C-H absorption at the to the . Where in this graph there are 1 weak overtone among the to the  among the transmittance and the wavenumber. The IR spectrum of the Benzene P as well as Benzene D is the one of the simplest simple which presents the expected of the aromatic C-H of the Benzene P and aromatic d6 C-D for the Benzene D resonances. Whereas the C-H stretches occurs to the  as the troughs along with the C-H around the  Benzene P and Benzene D.

DMSO P&D

            The above graph is the IR spectrum of the DMSO D (DMSO C-H) and the DMSO P. In this most of the organic compound has the features for the C-H vibrations which is not used for the interpreting the routine of the IR spectrum. In the dipole moment with respect to wavenumber for eth C-H stretching that is greater than others, that why the C-H stretch band is not the more intense. Now in the DMSO PD the C-H stretched is between the . And the in the DMSO P there is one peaks shown between the

Methanol P&D

            There is the IR spectrum of the Methanol D and Methanol P. Now the graph is between the transmittance as well as the wavenumber, for the Methanol D and Methanol P. Now in the Methanol D its show the two peaks that where the one peak is very small , and the other peaks start form the  and Methanol P is also start form the  but it has only one peaks . The IR spectrum for the Methanol is used in the studied of the IR peaks, where the Methanol D brought the interaction between a Methanol P molecule as well as ions electrolyte.

Results discussion of Info about the IR spectroscopy instrument

From the observation, the infrared portion of an electromagnetic spectrum of light is divided into three regions;

The near

Mid

Far- infrared

            Named for their relationship with the visible spectrum. The far-infrared is usually approximately 400-10 cm-1 (1000–30 μm), and it lies adjacent to the microwave region. This has low energy and could be useful in rotational spectroscopy. The mid-infrared is approximately 4000-400 cm-1 (30–1.4 μm) this could be used to study fundamental vibrations and the associated rotational-vibrational structures. The concepts of Infrared spectroscopy exploits the theory that molecules, atoms or elements have specific frequencies at which they spin, rotate or vibrate in a manner that corresponds to discrete energy levels. This sounds similar to the orbital spin concept of organic/quantum Chemistry, these resonant frequencies depend on the molecular shape of the potential energy, the masses of the atoms and the associated vibronic coupling. This takes advantage of the dipole concept by bonding atoms.

            Therefore, through the analyzed reagents, the rotation of the atoms in each molecule differs, and this affects the bond. The resonant frequencies across the analyzed molecules can be in a first approach and are also considering the relationship with the strength of the bond, and the total relative atomic mass at either end of it. Thus, the frequencies can be associated to a particular bond type.

References of Info about the IR spectroscopy instrument

Cary, SAS Institute Inc. (2003) Statistical Analysis System, user´s guide. Version 9.2. Statistical Analysis System Institute.

Martin Chaplin. Infrared Spectroscopy.pdf. Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 UK: England & Wales License.2013