CCCBDB listing of experimental data page 2

Other names
1,3,5,7-Cyclooctatetraene; [8]Annulene; cot; (1Z,3Z,5Z,7Z)-cycloocta-1,3,5,7-tetraene;

INChI	INChIKey	SMILES	IUPAC name
InChI=1S/C8H8/c1-2-4-6-8-7-5-3-1/h1-8H/b2-1-,3-1-,4-2-,5-3-,6-4-,7-5-,8-6-,8-7-	KDUIUFJBNGTBMD-BONZMOEMSA-N	C1=C\C=C/C=C\C=C/1	(1Z,3Z,5Z,7Z)-cycloocta-1,3,5,7-tetraene

State	Conformation
¹A₁	D2D

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)	297.60	1.40	kJ mol^-1	1970COX/PIL
Hfg(0K)		1.40	kJ mol^-1	1970COX/PIL
Entropy (298.15K)	326.80	1.50	J K^-1 mol^-1	webbook
Integrated Heat Capacity (0 to 298.15K)			kJ mol^-1
Heat Capacity (298.15K)	122.60	3.50	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 C₈H₈ (cyclooctatetraene).

Rotational Constants (cm^-1)

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

A	B	C	reference	comment
	0.09041		2008Kum/Lob:9134

Calculated rotational constants for C₈H₈ (cyclooctatetraene).

Product of moments of inertia
	amu³Å⁶		0	gm³ cm⁶

Geometric Data
picture of cyclooctatetraene

Point Group D_2d

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
rCH	1.079	0.001	1	9			2008Kum/Lob:9134	re
rCC	1.337	0.001	1	2			2008Kum/Lob:9134	re
rCC	1.470	0.001	1	5			2008Kum/Lob:9134	re
rCC	2.511	0.030	1	6			1976Hellwege(II/7)	not bonded
rCH	2.091	0.020	1	10			1976Hellwege(II/7)	not bonded
aCCC	126.55	0.01	1	2	6		1976Hellwege(II/7)	ae
aHCC	117.698	0.004	1	2	10		2008Kum/Lob:9134	ae
aHCC	115.613	0.005	1	5	13		2008Kum/Lob:9134	ae

Cartesians

Atom	x (Å)	y (Å)	z (Å)
C1	-0.2627	-1.6663	0.3833
C2	1.0331	-1.3409	0.3827
C3	-1.0297	1.3407	0.3845
C4	0.2630	1.6666	0.3835
C5	-1.3424	-1.0272	-0.3796
C6	1.6770	-0.2635	-0.3837
C7	-1.6841	0.2615	-0.3911
C8	1.3455	1.0312	-0.3823
H9	-0.5690	-2.5492	0.9659
H10	1.7214	-1.9720	0.9656
H11	-1.7184	1.9710	0.9702
H12	0.5706	2.5481	0.9698
H13	-1.9688	-1.7275	-0.9575
H14	2.5603	-0.5678	-0.9650
H15	-2.5689	0.5611	-0.9710
H16	1.9751	1.7236	-0.9613

Atom - Atom Distances bond lengths

Distances in Å

	C1	C2	C3	C4	C5	C6	C7	C8	H9	H10	H11	H12	H13	H14	H15	H16
C1		1.3360	3.1032	3.3740	1.4683	2.5137	2.5172	3.2324	1.1013	2.0903	3.9614	4.3358	2.1707	3.3157	3.4804	4.2787
C2	1.3360		3.3832	3.1045	2.5144	1.4707	3.2481	2.5119	2.0897	1.1008	4.3456	3.9602	3.3101	2.1787	4.2923	3.4764
C3	3.1032	3.3832		1.3331	2.5077	3.2388	1.4814	2.5150	3.9600	4.3451	1.1021	2.0883	3.4780	4.2839	2.1942	3.3146
C4	3.3740	3.1045	1.3331		3.2274	2.5126	2.5230	1.4703	4.3364	3.9629	2.0888	1.1025	4.2777	3.4768	3.3281	2.1778
C5	1.4683	2.5144	2.5077	3.2274		3.1145	1.3333	3.3855	2.1737	3.4770	3.3094	4.2735	1.1031	3.9730	2.0920	4.3487
C6	2.5137	1.4707	3.2388	2.5126	3.1145		3.4019	1.3364	3.4772	2.1775	4.2842	3.3107	3.9705	1.1003	4.3649	2.0907
C7	2.5172	3.2481	1.4814	2.5230	1.3333	3.4019		3.1259	3.3144	4.2927	2.1856	3.4877	2.0876	4.3626	1.0994	3.9816
C8	3.2324	2.5119	2.5150	1.4703	3.3855	1.3364	3.1259		4.2781	3.3132	3.4785	2.1748	4.3503	2.0909	3.9862	1.1005
H9	1.1013	2.0897	3.9600	4.3364	2.1737	3.4772	3.3144	4.2781		2.3621	4.6641	5.2232	2.5168	4.1770	4.1743	5.3333
H10	2.0903	1.1008	4.3451	3.9629	3.4770	2.1775	4.2927	3.3132	2.3621		5.2325	4.6643	4.1684	2.5303	5.3454	4.1755
H11	3.9614	4.3456	1.1021	2.0888	3.3094	4.2842	2.1856	3.4785	4.6641	5.2325		2.3606	4.1782	5.3383	2.5455	4.1754
H12	4.3358	3.9602	2.0883	1.1025	4.2735	3.3107	3.4877	2.1748	5.2232	4.6643	2.3606		5.3332	4.1726	4.1918	2.5261
H13	2.1707	3.3101	3.4780	4.2777	1.1031	3.9705	2.0876	4.3503	2.5168	4.1684	4.1782	5.3332		4.6752	2.3659	5.2407
H14	3.3157	2.1787	4.2839	3.4768	3.9730	1.1003	4.3626	2.0909	4.1770	2.5303	5.3383	4.1726	4.6752		5.2519	2.3649
H15	3.4804	4.2923	2.1942	3.3281	2.0920	4.3649	1.0994	3.9862	4.1743	5.3454	2.5455	4.1918	2.3659	5.2519		4.6904
H16	4.2787	3.4764	3.3146	2.1778	4.3487	2.0907	3.9816	1.1005	5.3333	4.1755	4.1754	2.5261	5.2407	2.3649	4.6904

Calculated geometries for C₈H₈ (cyclooctatetraene).

Experimental Bond Angles (degrees) from cartesians

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C6	127.105	C1	C2	H10	117.820
C1	C5	C7	127.854	C1	C5	H13	114.419
C2	C1	C5	127.370	C2	C1	H9	117.722
C2	C6	C8	126.908	C2	C6	H14	115.099
C3	C4	C8	127.491	C3	C4	H12	117.747
C3	C7	C5	125.898	C3	C7	H15	115.672
C4	C3	C7	127.305	C4	C3	H11	117.810
C4	C8	C6	127.000	C4	C8	H16	115.044
C5	C1	H9	114.792	C5	C7	H15	118.304
C6	C2	H10	114.967	C6	C8	H16	117.842
C7	C3	H11	114.760	C7	C5	H13	117.616
C8	C4	H12	114.654	C8	C6	H14	117.880

Bond descriptions

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

Bond Type	Count
C-C	4
C=C	4
H-C	8

Connectivity

Atom 1	Atom 2
C1	C2
C1	C5
C1	H9
C2	C6
C2	H10
C3	C4
C3	C7
C3	H11
C4	C8
C4	H12
C5	C7
C5	H13
C6	C8
C6	H14
C7	H15
C8	H16

Electronic energy levels (cm^-1)

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

Electron Affinity (eV)

Electron Affinity	unc.	reference
0.550	0.020	2002Rie/Tsc:231

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	D_2d	True							D_2d	0	1

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 C₈H₈ (cyclooctatetraene).
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	D_2d	True						D_2d	0	1

Calculated electric quadrupole moments for C₈H₈ (cyclooctatetraene).

References
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squib	reference	DOI
1970COX/PIL	J.D. Cox, G. Pilcher, "Thermochemistry of Organic and Organometallic Compounds" Academic Press, London, 1970	10.1002/bbpc.19700740727
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.
2002Rie/Tsc:231	JC Rienstra-Kiracofe, GS Tschumper, HF Schaefer III, S Nandi, GB Ellison "Atomic and Molecular Electron Affinities: Photoelectron Experiments and Theoretical Computations" Chemical Reviews 2002, 102, 231-282	10.1021/cr990044u
2008Kum/Lob:9134	DS Kummli, S Lobsiger, H-M Frey, S Leutwyler, JF Stanton, "Accurate Determination of the Structure of Cyclooctatetraene by Femtosecond Rotational Coherence Spectroscopy and ab Initio Calculations" J. Phys. Chem. A 2008, 112, 9134-9143	10.1021/jp803523y
webbook	NIST Chemistry Webbook (http://webbook.nist.gov/chemistry)	10.18434/T4D303

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You are here: Experimental > One molecule all properties

Atom 1	Atom 2
C1	C2
C1	C5
C1	H9
C2	C6
C2	H10
C3	C4
C3	C7
C3	H11
C4	C8
C4	H12
C5	C7
C5	H13
C6	C8
C6	H14
C7	H15
C8	H16

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Atom 1	Atom 2
C1	C2
C1	C5
C1	H9
C2	C6
C2	H10
C3	C4
C3	C7
C3	H11
C4	C8
C4	H12
C5	C7
C5	H13
C6	C8
C6	H14
C7	H15
C8	H16

Experimental data for C8H8 (cyclooctatetraene)

Experimental data for C₈H₈ (cyclooctatetraene)

Atom 1	Atom 2
C1	C2
C1	C5
C1	H9
C2	C6
C2	H10
C3	C4
C3	C7
C3	H11
C4	C8
C4	H12
C5	C7
C5	H13
C6	C8
C6	H14
C7	H15
C8	H16