Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)

Property	Value	Uncertainty	units	Reference	Comment
Hfg(298.15K)	125.52		kJ mol-1	webbook
Hfg(0K)			kJ mol-1	webbook
Entropy (298.15K)	231.61		J K-1 mol-1	webbook

Information can also be found for this species in the NIST Chemistry Webbook

Vibrational levels (cm^-1)

Mode Number	Symmetry	Frequency (cm-1)	Frequency Reference	Intensity (km mol-1)	Int. unc.	Intensity Reference	Comment
1	Σ+	3355	webbook
2	Σ+	2255	webbook
3	Σ+	1055	webbook
4	Π	578	webbook
5	Π	367	webbook

vibrational zero-point energy: 4277.5 cm^-1
Calculated vibrational frequencies for HCCF (Fluoroacetylene).

Rotational Constants (cm^-1)
See section I.F.4 to change rotational constant units

A	B	C	reference	comment
	0.32376	0.32376	1963Tyl/She:2661

Calculated rotational constants for HCCF (Fluoroacetylene).

Product of moments of inertia
52.06771	amu Å2		8.646182E-39	gm cm2

Geometric Data

Point Group C_∞v

Internal coordinates
distances (r) in Å, angles (a) in degrees, dihedrals (d) in degrees

Description	Value	unc.	Connectivity				Reference	Comment
			Atom 1	Atom 2	Atom 3	Atom 4
rCC	1.198	0.003	1	2			1976Hellwege(II/7)
rCF	1.279	0.005	1	3			1976Hellwege(II/7)
rCH	1.053	0.005	2	4			1976Hellwege(II/7)
aCCF	180		2	1	3		1976Hellwege(II/7)
aHCC	180		1	2	4		1976Hellwege(II/7)

Cartesians

Atom	x (Å)	y (Å)	z (Å)
C1	0.0000	0.0000	-0.0942
C2	0.0000	0.0000	-1.2922
F3	0.0000	0.0000	1.1848
H4	0.0000	0.0000	-2.3452

Atom - Atom Distances
Distances in Å

	C1	C2	F3	H4
C1		1.1980	1.2790	2.2510
C2	1.1980		2.4770	1.0530
F3	1.2790	2.4770		3.5300
H4	2.2510	1.0530	3.5300

Calculated geometries for HCCF (Fluoroacetylene).

Experimental Bond Angles (degrees) from cartesians

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	H4	180.000		C2	C1	F3	180.000

Bond descriptions
Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond

Bond Type	Count
C#C	1
C-F	1
C-H	1

Connectivity

Atom 1	Atom 2
C1	C2
C1	F3
C2	H4

Electronic energy levels (cm^-1)

Energy (cm-1)	Degeneracy	reference	description
0	1		1Σ

Ionization Energies (eV)

Ionization Energy	I.E. unc.	vertical I.E.	v.I.E. unc.	Electron Affinity	E.A. unc.	reference
11.260						webbook

Dipole, Quadrupole and Polarizability
Electric dipole moment
Calculated electric dipole moments for HCCF (Fluoroacetylene).
Electric quadrupole moment

Quadrupole (D Å)			Reference	comment
xx	yy	zz
-1.980	-1.980	3.960	1971Fly/Ben:225	3.96 +- 0.14

Calculated electric quadrupole moments for HCCF (Fluoroacetylene).

References
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squib	reference	DOI
1971Fly/Ben:225	WH Flygare, RC Benson "The molecular Zeeman effect in diamagnetic molecules and the determination of molecular magnetic moments (g values), magnetic susceptibilities, and molecular quadrupole moments" Mol. Phys. 1971, 20 (2), 225-250	10.1080/00268977100100221
1976Hellwege(II/7)	Hellwege, KH and AM Hellwege (ed.). Landolt-Bornstein: Group II: Atomic and Molecular Physics Volume 7: Structure Data of Free Polyatomic Molecules. Springer-Verlag. Berlin. 1976.
webbook	NIST Chemistry Webbook (http://webbook.nist.gov/chemistry)

Got a better number? Please email us at cccbdb@nist.gov