CCCBDB listing of experimental data page 2

Other names
Phenylethyne; Ethynylbenzene;

INChI	INChIKey	SMILES	IUPAC name
InChI=1S/C8H6/c1-2-8-6-4-3-5-7-8/h1,3-7H	UEXCJVNBTNXOEH-UHFFFAOYSA-N	C#CC1=CC=CC=C1	Ethynylbenzene

State	Conformation
¹A₁	C2V

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

Property	Value	Uncertainty	units	Reference
Hfg(298.15K)	306.60	1.70	kJ mol^-1	webbook
Hfg(0K)		1.70	kJ mol^-1	webbook
Heat Capacity (298.15K)	114.89		J K^-1 mol^-1	webbook

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

Vibrational levels (cm^-1) vibrations

Mode Number	Symmetry	Frequency			Intensity			Comment	Description
Mode Number	Symmetry	Fundamental(cm^-1)	Harmonic(cm^-1)	Reference	(km mol^-1)	unc.	Reference	Comment	Description

Calculated vibrational frequencies for C₆H₅CCH (phenylacetylene).

Rotational Constants (cm^-1)

See section I.F.4 to change rotational constant units

A	B	C	reference	comment
0.18949	0.05103	0.04019	NISThydrocarbon

Calculated rotational constants for C₆H₅CCH (phenylacetylene).

Product of moments of inertia
1.232704E+07	amu³Å⁶		5.6445180160824E-113	gm³ cm⁶

Geometric Data
picture of phenylacetylene

Point Group C_2v

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

Description	Value	unc.	Connectivity				Reference	Comment
Description	Value	unc.	Atom 1	Atom 2	Atom 3	Atom 4	Reference	Comment
rCC	1.388	0.000	1	4			1987Kuchitsu(II/15)
rCC	1.396	0.001	4	6			1987Kuchitsu(II/15)
rCC	1.398	0.000	6	7			1987Kuchitsu(II/15)
rCC	1.448	0.001	1	2			1987Kuchitsu(II/15)
rCC	1.208	0.000	2	8			1987Kuchitsu(II/15)
rCH	1.055	0.000	8	9			1987Kuchitsu(II/15)
aCCC	120.8	0.4	3	1	4		1987Kuchitsu(II/15)
aCCC	119.8	0.4	1	4	6		1987Kuchitsu(II/15)
aCCC	119.9	0.2	4	6	7		1987Kuchitsu(II/15)

Cartesians

Atom	y (Å)	z (Å)
C1	0.0000	-0.5514
C2	0.0000	-1.9996
C3	-1.2067	0.1344
C4	1.2067	0.1344
C5	-1.2105	1.5299
C6	1.2105	1.5299
C7	0.0000	2.2310
C8	0.0000	-3.2079
H9	0.0000	-4.2631
H10	-2.1396	-0.4102
H11	2.1396	-0.0410
H12	-2.1467	2.0726
H13	2.1467	2.0726
H14	0.0000	3.3106

Atom - Atom Distances bond lengths

Distances in Å

	C1	C2	C3	C4	C5	C6	C7	C8	H9	H10	H11	H12	H13	H14
C1		1.4482	1.3880	1.3880	2.4077	2.4077	2.7824	2.6565	3.7117	2.1443	2.1996	3.3902	3.3902	3.8620
C2	1.4482		2.4515	2.4515	3.7313	3.7313	4.2306	1.2083	2.2635	2.6653	2.9007	4.6034	4.6034	5.3102
C3	1.3880	2.4515		2.4134	1.3955	2.7911	2.4191	3.5535	4.5601	1.0802	3.3509	2.1541	3.8732	3.3977
C4	1.3880	2.4515	2.4134		2.7911	1.3955	2.4191	3.5535	4.5601	3.3903	0.9492	3.8732	2.1541	3.3977
C5	2.4077	3.7313	1.3955	2.7911		2.4210	1.3989	4.8900	5.9181	2.1511	3.7001	1.0821	3.4008	2.1532
C6	2.4077	3.7313	2.7911	1.3955	2.4210		1.3989	4.8900	5.9181	3.8713	1.8251	3.4008	1.0821	2.1532
C7	2.7824	4.2306	2.4191	2.4191	1.3989	1.3989		5.4389	6.4941	3.3991	3.1209	2.1525	2.1525	1.0796
C8	2.6565	1.2083	3.5535	3.5535	4.8900	4.8900	5.4389		1.0552	3.5221	3.8219	5.7002	5.7002	6.5185
H9	3.7117	2.2635	4.5601	4.5601	5.9181	5.9181	6.4941	1.0552		4.4071	4.7333	6.6895	6.6895	7.5737
H10	2.1443	2.6653	1.0802	3.3903	2.1511	3.8713	3.3991	3.5221	4.4071		4.2951	2.4828	4.9534	4.2921
H11	2.1996	2.9007	3.3509	0.9492	3.7001	1.8251	3.1209	3.8219	4.7333	4.2951		4.7791	2.1136	3.9763
H12	3.3902	4.6034	2.1541	3.8732	1.0821	3.4008	2.1525	5.7002	6.6895	2.4828	4.7791		4.2934	2.4781
H13	3.3902	4.6034	3.8732	2.1541	3.4008	1.0821	2.1525	5.7002	6.6895	4.9534	2.1136	4.2934		2.4781
H14	3.8620	5.3102	3.3977	3.3977	2.1532	2.1532	1.0796	6.5185	7.5737	4.2921	3.9763	2.4781	2.4781

Calculated geometries for C₆H₅CCH (phenylacetylene).

Experimental Bond Angles (degrees) from cartesians

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C8	180.000	C1	C3	C5	119.767
C1	C3	H10	120.114	C1	C4	C6	119.767
C1	C4	H11	139.740	C2	C1	C3	119.611
C2	C1	C4	119.611	C2	C8	H9	180.000
C3	C1	C4	120.779	C3	C5	C7	119.923
C3	C5	H12	120.256	C4	C6	C7	119.923
C4	C6	H13	120.256	C5	C3	H10	120.119
C5	C7	C6	119.843	C5	C7	H14	120.079
C6	C4	H11	100.493	C6	C7	H14	120.079
C7	C5	H12	119.821	C7	C6	H13	119.821

Bond descriptions

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

Bond Type	Count
C:C	6
C-C	1
C#C	1
H-C	6

Connectivity

Atom 1	Atom 2
C1	C2
C1	C3
C1	C4
C2	C8
C3	C5
C3	H10
C4	C6
C4	H11
C5	C7
C5	H12
C6	C7
C6	H13
C7	H14
C8	H9

Electronic energy levels (cm^-1)

Energy (cm^-1)	Degeneracy	reference	description
0	1		¹A₁

Ionization Energies (eV)

Ionization Energy	I.E. unc.	vertical I.E.	v.I.E. unc.	reference
8.820	0.020

Dipole, Quadrupole and Polarizability
Electric dipole moment dipole

State	Config	State description	Conf description	Exp. min.	Dipole (Debye)				Reference	comment	Point Group	Components
State	Config	State description	Conf description	Exp. min.	x	y	z	total	Reference	comment	Point Group	dipole	quadrupole
1	1	¹A₁	C_2v	True				0.656	NISThydrocarbon		C_2v	1	2

Experimental dipole measurement abbreviations: MW microwave; DT Dielectric with Temperature variation; DR Indirect (usually an upper limit); MB Molecular beam
Calculated electric dipole moments for C₆H₅CCH (phenylacetylene).
Electric quadrupole moment

State	Config	State description	Conf description	Exp. min.	Quadrupole (D Å)			Reference	comment	Point Group	Components
State	Config	State description	Conf description	Exp. min.	xx	yy	zz	Reference	comment	Point Group	dipole	quadrupole
1	1	¹A₁	C_2v	True						C_2v	1	2

Calculated electric quadrupole moments for C₆H₅CCH (phenylacetylene).

References
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squib	reference	DOI
1987Kuchitsu(II/15)	Kuchitsu (ed.), Landolt-Bornstein: Group II: Atomic and Molecular Physics Volume 15: Structure Data of Free Polyatomic Molecules. Springer-Verlag, Berlin, 1987.
NISThydrocarbon	NIST Hydrocarbon spectral database (http://www.physics.nist.gov/PhysRefData/MolSpec/Hydro/index.html)	10.18434/T4PC70
webbook	NIST Chemistry Webbook (http://webbook.nist.gov/chemistry)	10.18434/T4D303

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Atom 1	Atom 2
C1	C2
C1	C3
C1	C4
C2	C8
C3	C5
C3	H10
C4	C6
C4	H11
C5	C7
C5	H12
C6	C7
C6	H13
C7	H14
C8	H9

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Atom 1	Atom 2
C1	C2
C1	C3
C1	C4
C2	C8
C3	C5
C3	H10
C4	C6
C4	H11
C5	C7
C5	H12
C6	C7
C6	H13
C7	H14
C8	H9

Experimental data for C6H5CCH (phenylacetylene)

Experimental data for C₆H₅CCH (phenylacetylene)

Atom 1	Atom 2
C1	C2
C1	C3
C1	C4
C2	C8
C3	C5
C3	H10
C4	C6
C4	H11
C5	C7
C5	H12
C6	C7
C6	H13
C7	H14
C8	H9