Ethyne, difluoro-
- Formula: C2F2
- Molecular weight: 62.0182
- IUPAC Standard InChI: InChI=1S/C2F2/c3-1-2-4
- IUPAC Standard InChIKey: BWTZYYGAOGUPFQ-UHFFFAOYSA-N
- CAS Registry Number: 689-99-6
- Chemical structure:
This structure is also available as a 2d Mol file - Other names: Acetylene, difluoro-; Difluoroacetylene; FC≡CF; Difluoroethyne; C2F2
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Options:
Gas phase thermochemistry data
Go To: Top, Vibrational and/or electronic energy levels, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | 5.000 | kcal/mol | Review | Chase, 1998 | Data last reviewed in December, 1967 |
| ΔfH°gas | -45. ± 6. | kcal/mol | Eqk | Ehlert, 1969 | ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 58.332 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1967 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = A + B*t + C*t2 + D*t3 +
E/t2
H° − H°298.15= A*t + B*t2/2 +
C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 −
E/(2*t2) + G
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
View plot Requires a JavaScript / HTML 5 canvas capable browser.
| Temperature (K) | 298. to 1200. | 1200. to 6000. |
|---|---|---|
| A | 9.158210 | 20.42670 |
| B | 21.44080 | 0.234936 |
| C | -15.77190 | -0.046015 |
| D | 4.277971 | 0.003107 |
| E | -0.058355 | -1.628120 |
| F | 1.251560 | -5.152570 |
| G | 63.35660 | 77.34369 |
| H | 5.000010 | 5.000010 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in December, 1967 | Data last reviewed in December, 1967 |
Vibrational and/or electronic energy levels
Go To: Top, Gas phase thermochemistry data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Marilyn E. Jacox
State: X
| Vib. sym. |
No. | Approximate type of mode |
cm-1 | Med. | Method | References | |
|---|---|---|---|---|---|---|---|
| Σg+ | 1 | CC stretch | 2436 | T | gas | IR | Burger, Schneider, et al., 1991 McNaughton and Elmes, 1992 |
| 2 | CF s-stretch | 787 | T | gas | IR | Burger, Schneider, et al., 1991 McNaughton and Elmes, 1992 | |
| Σu+ | 3 | CF a-stretch | 1349.524 | gas | IR | Burger, Schneider, et al., 1991 Burger and Sommer, 1992 McNaughton and Elmes, 1992 | |
| 3 | CF a-stretch | 1346.9 | vs | Ne | IR | Burger, Schneider, et al., 1991 | |
| 3 | CF a-stretch | 1340.7 | vs | Ar | IR | Brahms and Dailey, 1989 Burger, Schneider, et al., 1991 | |
| Πg | 4 | Bend | 270 | T | gas | IR | Burger, Schneider, et al., 1991 McNaughton and Elmes, 1992 |
| Πu | 5 | Bend | 268 | T | gas | IR | McNaughton and Elmes, 1992 |
| 5 | Bend | 286.7 | w | Ar | IR | Burger, Schneider, et al., 1991 | |
| 5 | Bend | 279.3 | w | Ar | IR | Burger, Schneider, et al., 1991 | |
Additional references: Jacox, 1994, page 197
Notes
| w | Weak |
| vs | Very strong |
| T | Tentative assignment or approximate value |
References
Go To: Top, Gas phase thermochemistry data, Vibrational and/or electronic energy levels, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Chase, 1998
Chase, M.W., Jr.,
NIST-JANAF Themochemical Tables, Fourth Edition,
J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]
Ehlert, 1969
Ehlert, T.C.,
Bonding in C1 and C2 fluroides,
J. Phys. Chem., 1969, 73, 949-953. [all data]
Burger, Schneider, et al., 1991
Burger, H.; Schneider, W.; Sommer, S.; Thiel, W.; Willner, H.,
The vibrational spectrum and rotational constants of difluoroethyne FC 3/4 CF. Matrix and high resolution infrared studies and ab initio calculations,
J. Chem. Phys., 1991, 95, 8, 5660, https://doi.org/10.1063/1.461640
. [all data]
McNaughton and Elmes, 1992
McNaughton, D.; Elmes, P.,
Spectrochim. Acta, 1992, 48A, 605. [all data]
Burger and Sommer, 1992
Burger, H.; Sommer, S.,
The high-resolution infrared spectrum of FC«58876»CF: The 1350 and 2150 cm-1 regions,
J. Mol. Spectrosc., 1992, 151, 1, 148, https://doi.org/10.1016/0022-2852(92)90011-C
. [all data]
Brahms and Dailey, 1989
Brahms, J.C.; Dailey, W.P.,
Difluoromaleic anhydride as a source of matrix isolated difluoropropadienone, difluorocyclopropenone and difluoroacetylene,
J. Am. Chem. Soc., 1989, 111, 24, 8940, https://doi.org/10.1021/ja00206a039
. [all data]
Jacox, 1994
Jacox, M.E.,
Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Vibrational and/or electronic energy levels, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.