- About this Journal ·
- Abstracting and Indexing ·
- Aims and Scope ·
- Article Processing Charges ·
- Articles in Press ·
- Author Guidelines ·
- Bibliographic Information ·
- Citations to this Journal ·
- Contact Information ·
- Editorial Board ·
- Editorial Workflow ·
- Free eTOC Alerts ·
- Publication Ethics ·
- Reviewers Acknowledgment ·
- Submit a Manuscript ·
- Subscription Information ·
- Table of Contents
International Journal of Spectroscopy
Volume 2012 (2012), Article ID 474639, 5 pages
Integrated Band Intensities of Ethylene () by Fourier Transform Infrared Spectroscopy
Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616
Received 22 June 2012; Accepted 22 July 2012
Academic Editor: Karol Jackowski
Copyright © 2012 G. B. Lebron and T. L. Tan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The integrated band intensities of ethylene (12C2H4) in the 640–3260 cm−1 region were determined by Fourier transform infrared (FTIR) spectroscopy. The infrared absorbance spectra of the and , , , , , and and bands of ethylene recorded at a resolution of 0.5 cm−1 were measured at an ambient temperature of 296 K at various vapor pressures ranging from to atm to obtain respective Beer-Lambert's law plots. The measured integrated band intensities in cm−1/cm atm were , , , and . In addition, the measured infrared band intensities of the and combination bands of ethylene are reported for the first time: cm−1/cm atm and cm−1/cm atm.
Ethylene (12C2H4), the simplest of all alkenes, is an important hydrocarbon. Terrestrially, it is a known tropospheric pollutant that affects the ozone concentration in the atmosphere . It is produced by plants [2, 3], the incomplete combustion of fossil fuels , forest fires [5–7], volcanic emissions, and natural gas [4, 8]. As such, the measurement of ethylene concentration in the atmosphere is of great interest and importance. Beyond Earth, ethylene has been detected as a trace component of the atmospheres of the outer planets Jupiter, Saturn, Neptune [9–12], and the satellite Titan [13–18]. Ethylene has also been observed in circumstellar clouds IRC+10216  and IRL618 . The 10 μm band system of 12C2H4 which contains the strong band as well as the and bands is of particular interest to spectroscopists and astrophysicists as the region is being used for C2H4 remote measurements in the infrared range [21, 22].
Given the integrated band intensities of ethylene, it is possible to determine spectroscopically the concentration and distribution of ethylene in the atmosphere at any given temperature or pressure. Recent measurements of vibrational band intensities of 12C2H4 include the , , and bands [21–24] while Bach et al.  measured relative line intensities of the , + and bands. New data on the intensities and line positions in the band of 12C2H4 as reported by Rotger et al.  are included in the 2009 edition of the GEISA database  and in the HITRAN 2008 molecular spectroscopic database . Also included in the HITRAN database  are intensities of the , , and bands  of ethylene, and the calculated intensity ratio of the band to the band of ethylene . In this paper, we report the improved results of our laboratory measurements of the integrated band intensities of 12C2H4 between 640 cm−1 and 3260 cm−1 by Fourier transform infrared (FTIR) spectroscopy covering the following ethylene bands: and , , + , + , , and and + . To our knowledge, the measured integrated band intensities of + and + are reported for the first time. This work is part of our FTIR studies of the ethylene molecule and its isotopomers [31–34].
2. Experimental Details
The ethylene gas samples used in the experiments with a stated purity of 99.99% were purchased from Sigma-Aldrich in USA. All unapodized spectra were recorded at a resolution of 0.5 cm−1 in the 640–3260 cm−1 region using a Bruker IFS 125 HR Michelson Fourier transform spectrometer located at the Spectroscopy Laboratory of the National Institute of Education, Nanyang Technological University in Singapore. A globar infrared source together with a high-sensitivity liquid nitrogen cooled Hg-Cd-Te detector and KBr beamsplitter were used for all recordings. The spectra were collected at an ambient temperature of 296 K and at about 30 different vapor pressures in the 3 × 10−5 to 1 × 10−3 atm (0.03–1.00 mb) range as measured by a capacitance pressure gauge. An absorption length of 0.80 m was achieved by adjusting for four passes in the multiple-pass absorption cell with a 20-cm base path. A total of 100 scans were coadded to produce each spectrum of high signal-to-noise ratio. A background spectrum of the evacuated cell was recorded at the same resolution. The ratio of the 12C2H4 spectrum to the background spectrum yielded a transmittance spectrum with relatively smooth baseline. The transmittance spectrum was then converted to absorbance spectrum () and the area for each band in the region was determined at different pressures using the OPUS 6 software.
3. Results and Discussion
The vibrational bands of pure ethylene vapor in the 640–3260 cm−1 wavenumber region are shown in the survey absorbance spectrum in Figure 1. The spectrum was recorded at a resolution of 0.5 cm−1 at a 4.56 × 10−4 atm vapour pressure and at an ambient temperature of 296 K. Figure 1 also shows the overlapping of the and bands at the far right and of the and + bands at the opposite end of the spectrum.
The integrated band intensity, is given by the equation [35, 36]: where is the vapor pressure in the cell, is the path length, and and are the incident and transmitted intensities of light at frequency . To find , the absorbance area of each band in the ethylene spectrum was determined for different pressures. The band area (cm−1) was then plotted against pressure (atm) and the integrated band intensities in cm−1/cm atm were determined from the gradient of each plot. The experimental gas path length () used in the calculation was 0.80 m. The procedure used in the determination of is similar to that of Kagann and Maki . In Figure 2, the Beer-Lambert’s law plots are shown for the and + , , + , and + bands of ethylene. Straight lines passing through the origin were accurately fitted with correlation coefficient ranging from 0.985 to 0.990.
Table 1 presents the results of the present work together with those of previous works [21, 22, 29, 35] for comparison. Previously reported integrated band intensities of the and bands of 12C2H4 were from Golike et al. : = cm−1/cm atm at band center = 3105.5 cm−1 and = cm−1/cm atm at band center = 2985.5 cm−1. A more recent study  included in the HITRAN database  that involves 148 selected measurements in the 3 μm region of 12C2H4 gives the integrated band intensities of the and bands as = cm−1/cm atm at = 3104.885 cm−1 and = cm−1/cm atm at = 3012.436 cm−1. In our work, since the band closely overlaps with the + combination band, we could only determine the combined band intensity of S( and + ) = cm−1/cm atm. The ratio of S( and + ) to calculated as 2.0 was found to be close to the value of 1.8 determined by Bach et al.  in their FTIR rotational analysis. For the isolated band, = cm−1/cm atm at = 2989 cm−1 was determined in our work. These values, and , closely agree with those obtained by Golike et al.  but differ with those reported by Dang-Nhu et al.  (see Table 1). The discrepancy in the values obtained may be explained by the different band center used by Dang-Nhu et al. in their study. Their band center = 3012.436 cm−1 for the band of 12C2H4 is a few wavenumbers off from what Golike et al.  and our work had used which are close to what is reported in recent literature (~2989 cm−1) [25, 37]. For the band, our result of = cm−1/cm atm agrees well with the latest reported value of = cm−1/cm atm  in the updated GEISA  and HITRAN  databases. For the first time, the integrated band intensities of the weak + and strong + combination bands have been measured. Moreover, high accuracy is shown in the values of S( + ) = cm−1/cm atm and S( + ) = cm−1/cm atm. The areas of the overlapping bands, and , and and + , were not separated and the integrated intensities of these bands are reported as combined (see Table 1). As expected, the strong band has the largest band intensity in the region with very small contribution from the overlapping but weak band, = cm−1/cm atm . Overall, our results which show good agreement with those from previous studies are more accurately determined.
The authors thank the National Institute of Education, Singapore for the financial support extended to the project through research grants RS 3/08 TTL and RI 9/09 TTL.
- M. A. Loroño Gonzalez, V. Boudon, M. Loëte et al., “High-resolution spectroscopy and preliminary global analysis of C-H stretching vibrations of C2H4 in the 3000 and 6000 cm−1 regions,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 111, no. 15, pp. 2265–2278, 2010.
- F. B. Abeles, P. W. Morgan, and M. E. J. Saltveit, Ethylene in Plant Biology, Academic Press, London, UK, 1992.
- H. Imaseki, “The biochemistry of ethylene biosynthesis,” in The Plant Hormone Ethylene, A. K. Mattoo and J. C. Suttle, Eds., pp. 1–20, CRC Press, Boca Raton, Fla, USA, 1991.
- S. Sawada and T. Totsuka, “Natural and anthropogenic sources and fate of atmospheric ethylene,” Atmospheric Environment, vol. 20, no. 5, pp. 821–832, 1986.
- C. P. Rinsland, C. Paton-Walsh, N. B. Jones et al., “High spectral resolution solar absorption measurements of ethylene (C2H4) in a forest fire smoke plume using HITRAN parameters: tropospheric vertical profile retrieval,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 96, no. 2, pp. 301–309, 2005.
- R. J. Yokelson, J. G. Goode, D. E. Ward et al., “Emissions of formaldehyde, acetic acid, methanol and other trace gases from biomass fires in North Carolina measured by airborne Fourier transform infared spectroscopy,” Journal Geophysical Research, vol. 104, no. 23, pp. 30109–30125, 1999.
- P. F. Coheur, H. Herbin, C. Clerbaux et al., “ACE-FTS observation of a young biomass burning plume: first reported measurements of C2H4, C3H6O, H2CO and PAN by infrared occultation from space,” Atmospheric Chemistry and Physics, vol. 7, no. 20, pp. 5437–5446, 2007.
- R. E. Stoiber, D. C. Leggett, T. F. Jenkins, R. P. Murrmann, and W. I. J. Rose, “Organic compounds in volcanic gas from Santiaguito Volcano, Guatemala,” Geological Society of America Bulletin, vol. 82, no. 8, pp. 2299–2302, 1971.
- T. Kostiuk, P. Romani, F. Espenak, T. A. Livengood, and J. J. Goldstein, “Temperature and abundances in the Jovian auroral stratosphere 2. Ethylene as a probe of the microbar region,” Journal of Geophysical Research, vol. 98, no. 10, pp. 18823–18830, 1993.
- C. A. Griffith, B. Bézard, T. K. Greathouse, D. M. Kelly, J. H. Lacy, and K. S. Noll, “Thermal infrared imaging spectroscopy of Shoemaker-Levy 9 impact sites: spatial and vertical distributions of NH3, C2H4, and 10-μm dust emission,” Icarus, vol. 128, no. 2, pp. 275–293, 1997.
- B. Bezard, J. L. Moses, J. Lacy, T. Greathouse, M. Richter, and C. Griffith, “Detection of ethylene (C2H4) on Jupiter and Saturn in non-auroral regions,” Bulletin of the American Astronomical Society, vol. 33, p. 1079, 2001.
- B. Schulz, T. Encrenaz, B. Bezard, P. Romani, E. Lellouch, and S. K. Atreya, “Detection of C2H4 in Neptune from ISO/PHT-S observations,” Astronomy & Astrophysics, vol. 350, pp. L13–L17, 1999.
- W. C. Saslaw and R. L. Wildey, “On the chemistry of Jupiter's upper atmosphere,” Icarus, vol. 7, no. 1–3, pp. 85–93, 1967.
- A. Coustenis, R. K. Achterberg, B. J. Conrath et al., “The composition of Titan's stratosphere from Cassini/CIRS mid-infrared spectra,” Icarus, vol. 189, no. 1, pp. 35–62, 2007.
- V. G. Kunde, A. C. Aikin, R. A. Hanel, D. E. Jennings, W. C. Maguire, and R. E. Samuelson, “C4H2, HC3N and C2N2 in Titan's atmosphere,” Nature, vol. 292, no. 5825, pp. 686–688, 1981.
- A. Bar-Nun and M. Podolak, “The photochemistry of hydrocarbons in Titan's atmosphere,” Icarus, vol. 38, no. 1, pp. 115–122, 1979.
- A. Coustenis, A. Salama, B. Schulz et al., “Titan's atmosphere from ISO mid-infrared spectroscopy,” Icarus, vol. 161, no. 2, pp. 383–403, 2003.
- R. J. Vervack Jr., B. R. Sandel, and D. F. Strobel, “New perspectives on Titan's upper atmosphere from a reanalysis of the Voyager 1 UVS solar occultations,” Icarus, vol. 170, no. 1, pp. 91–112, 2004.
- A. L. Betz, “Ethylene in IRC +10216,” The Astrophysical Journal, vol. 244, pp. L103–L105, 1981.
- J. Cernicharo, A. M. Heras, J. R. Pardo et al., “Methylpolyynes and small hydrocarbons in CRL 618,” The Astrophysical Journal Letters, vol. 546, no. 2, pp. L127–L130, 2001.
- M. Rotger, V. Boudon, and J. Vander Auwera, “Line positions and intensities in the band of ethylene near 1450 cm−1: an experimental and theoretical study,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 109, no. 6, pp. 952–962, 2008.
- W. E. Blass, J. J. Hillman, A. Fayt et al., “10 μm ethylene: spectroscopy, intensities and a planetary modeler's atlas,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 71, no. 1, pp. 47–60, 2001.
- D. C. Reuter and J. M. Sirota, “Absolute intensities and foreign gas broadening coefficients of the and lines in the band of C2H4,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 50, no. 5, pp. 477–482, 1993.
- J. Walrand, M. Lengelé, G. Blanquet, and M. Lepère, “Absolute line intensities determination in the band of C2H4,” Spectrochimica Acta A, vol. 59, no. 3, pp. 421–426, 2003.
- M. Bach, R. Georges, M. Hepp, and M. Herman, “Slit-jet Fourier transform infrared spectroscopy in 12C2H4: cold and hot bands near 3000 cm−1,” Chemical Physics Letters, vol. 294, no. 6, pp. 533–537, 1998.
- N. Jacquinet-Husson, L. Crepeau, R. Armante et al., “The 2009 edition of the GEISA spectroscopic database,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 112, no. 15, pp. 2395–2445, 2011.
- L. S. Rothman, I. E. Gordon, A. Barbe et al., “The HITRAN 2008 molecular spectroscopic database,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 110, no. 9-10, pp. 533–572, 2009.
- L. S. Rothman, A. Barbe, D. Chris Benner et al., “The HITRAN molecular spectroscopic database: edition of 2000 including updates through 2001,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 82, pp. 5–44, 2003.
- M. Dang-Nhu, A. S. Pine, A. Fayt, M. D. Vleeschouwer, and C. Lambeau, “Les intensités dans la pentade , , , et de 12C2H4,” Canadian Journal of Physics, vol. 61, no. 3, pp. 514–521, 1983.
- I. Cauuet, J. Walrand, G. Blanquet et al., “Extension to third-order Coriolis terms of the analysis of , , and levels of ethylene on the basis of Fourier transform and diode laser spectra,” Journal of Molecular Spectroscopy, vol. 139, no. 1, pp. 191–214, 1990.
- T. L. Tan, S. Y. Lau, P. P. Ong, K. L. Goh, and H. H. Teo, “High-resolution Fourier transform infrared spectrum of the fundamental band of ethylene (C2H4),” Journal of Molecular Spectroscopy, vol. 203, no. 2, pp. 310–313, 2000.
- G. B. Lebron and T. L. Tan, “High-resolution FTIR measurement and analysis of the band of C2H3D,” Journal of Molecular Spectroscopy, vol. 261, no. 2, pp. 119–123, 2010.
- G. B. Lebron and T. L. Tan, “Improved rovibrational constants for the band of C2H3D,” Journal of Molecular Spectroscopy, vol. 265, no. 1, pp. 55–57, 2011.
- G. B. Lebron and T. L. Tan, “The high-resolution FTIR spectrum of the band of trans-d2-ethylene (trans-C2H2D2),” Journal of Molecular Spectroscopy, vol. 271, no. 1, pp. 44–49, 2012.
- R. C. Golike, I. M. Mills, W. B. Person, and B. Crawford, “Vibrational intensities. VI. Ethylene and its deuteroisotopes,” The Journal of Chemical Physics, vol. 25, no. 6, pp. 1266–1275, 1956.
- R. H. Kagann and A. G. Maki, “Infrared absorption intensities for N2O3,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 31, no. 2, pp. 173–176, 1984.
- R. Georges, M. Bach, and M. Herman, “The vibrational energy pattern in ethylene (12C2H4),” Molecular Physics, vol. 97, no. 1-2, pp. 279–292, 1999.