Title

Determining the shape of 2-Fluorophenyl Acetylene using Microwave Spectroscopy

School Name

South Carolina Governor's School for Science and Mathematics

Grade Level

12th Grade

Presentation Topic

Chemistry

Presentation Type

Mentored

Abstract

Microwave spectroscopy is a tool used to analyze the rotational spectra of chemicals to determine the shape of a molecule. This is useful because a molecule’s shape determines its function. We measured the microwave spectrum of 2-Fluorophenyl Acetylene (2FPA) using a chirped-pulse Fourier transform microwave spectrometer. We sprayed 2FPA into the spectrometer which measured the rotational frequencies using microwaves with a frequency range of 8,000-18,000 MHz and averaged the data 10,000 times. We also used Gaussian 03W software to predict the rotation constants and the distortion constants of 2FPA. We used the SPCAT/SPFIT software programs to compare the patterns of the spectra from the Gaussian prediction and the data gathered using the spectrometer. We assigned 76 lines in the spectra and determined the rotational constants to be the following: A=2949.419100(92) MHz, B=1495.780700(63) MHz, C=992.230260(36) MHz and the distortion constants to be the following: DJ= 0.00003700(72) MHz, DelJK=0.0005440(26) MHz, DK=0.0004070(50) MHz, dj=0.00001130(36) MHz, dk=0.0003160(39) MHz. From these constants we can determine the shape of the molecule.

Location

HSS 202

Start Date

4-2-2022 10:15 AM

Presentation Format

Oral Only

Group Project

Yes

COinS
 
Apr 2nd, 10:15 AM

Determining the shape of 2-Fluorophenyl Acetylene using Microwave Spectroscopy

HSS 202

Microwave spectroscopy is a tool used to analyze the rotational spectra of chemicals to determine the shape of a molecule. This is useful because a molecule’s shape determines its function. We measured the microwave spectrum of 2-Fluorophenyl Acetylene (2FPA) using a chirped-pulse Fourier transform microwave spectrometer. We sprayed 2FPA into the spectrometer which measured the rotational frequencies using microwaves with a frequency range of 8,000-18,000 MHz and averaged the data 10,000 times. We also used Gaussian 03W software to predict the rotation constants and the distortion constants of 2FPA. We used the SPCAT/SPFIT software programs to compare the patterns of the spectra from the Gaussian prediction and the data gathered using the spectrometer. We assigned 76 lines in the spectra and determined the rotational constants to be the following: A=2949.419100(92) MHz, B=1495.780700(63) MHz, C=992.230260(36) MHz and the distortion constants to be the following: DJ= 0.00003700(72) MHz, DelJK=0.0005440(26) MHz, DK=0.0004070(50) MHz, dj=0.00001130(36) MHz, dk=0.0003160(39) MHz. From these constants we can determine the shape of the molecule.