NIST Hydrocarbon C3H6 tables

C₃H₆ - Propylene

Molecular constants for the ground state of propylene from fitting internal rotation and the A state alone
Parameter	Fit to A and E States Value	Uncertainties	Parameter	Fit to A State Value	Uncertainties
A [MHz]	46 280.33(23)	^a	A″ [MHz]	46 290.523(204)	^b
B [MHz]	9305.238(25)		B″ [MHz]	9305.354(25)
C [MHz]	8134.214(23)		C″ [MHz]	8134.314(21)
Δ_J	0.006 554(83)		τ₁	0.0174(352)
Δ_JK	-0.0264(84)		τ₂	-0.0141(60)
Δ_K	0.479(49)		τ₃	1.037(130)
δ_J	0.001 238(312)		τ_aaaa	-2.794(154)
δ_K	-0.0291(22)		τ_bbbb	-0.0348(23)
I_α (u Å²)	3.16 ^c		τ_cccc	-0.0151(20)
θ	28.84°
V₃ (cm^-1)	687.87(7)

^a Uncertainties 1σ.

^b Uncertainties 2σ.

^c Value fixed.

Dipole Moment and Zeeman constants for propylene
Parameter	Value	Ref.
Electric Dipole Moment
µ_a [C · m] µ_a [D]	1.201(33) x 10^-30 0.360(1)	57015
µ_b [C · m] µ_b [D]	0.167(67) x 10^-30 0.05(2)	57015
Zeeman Parameters
g_aa	-0.0789(6) µ_N	69065
g_bb	-0.0424(4) µ_N
g_cc	+0.0107(5) µ_N
2χ_aa - χ_bb - χ_cc	-0.74(3) x 10^-6 erg/G² · mol
-χ_aa + 2χ_bb - χ_cc	+13.4(5) x 10^-6 erg/G² · mol
Q_aa	0.6(3) x 10^-26 esu · cm²
Q_bb	2.9(5) x 10^-26 esu · cm²
Q_cc	-3.5(7) x 10^-26 esu · cm²

Molecular constants for propylene (CH₃CH=CH₂) in excited torsional states
Parameter	ν = 1 State	ν = 2 State	Ref.
A [MHz]	46280. ^a	46280. ^a	66045
B [MHz]	9293.902	9282.001
C [MHz]	8138.561	8142.708
I_α (u Å²)	3.160 ^a	3.160 ^a
θ	(24.8°)	(24.6°)
λ_a	0.907 62	0.908 98
λ_b	0.419 80	0.416 84
V₃ (cm^-1)	697.48	703.65
s	43.652	44.005
F (cm^-1)	7.1010	7.1063

^a Values fixed in the analysis.

Molecular constants for the deuterated propylene species *trans*-CHDCHCH₃ and H₂CDCH₃ in the ground and excited torsional states
Parameter	t-CHDCHCH₃		CH₂CDCH₃		Ref.
Parameter	ν = 0	ν = 1	ν = 0	ν = 1	Ref.
A [MHz]	45 912.6 ^a	45 912.6 ^a	38 154.2 ^a	38 154.2 ^a	66045
B [MHz]	8548.01	8538.45	9301.81	9290.65
C [MHz]	7542.20	7546.21	7837.18	7839.64
I_α (u Å²)	3.16 ^a	3.16 ^a	3.16 ^a	3.16 ^a
λ_a	0.924	0.913	0.897	0.909
λ_b	0.381	0.408	0.442	0.415
V₃ (cm^-1)	691.	699.1	688.	698.9
s	43.0	43.78	45.6	46.19
F (cm^-1)	7.144	7.096	6.697	6.731

^a Fixed value.

Rotational constants for substituted isotopic forms of propylene
Species	A [GHz]	B [MHz]	C [MHz]	Ref.
¹³CH₂CHCH₃	46.00(20)	9048.33(5)	8430.84(5)	61013
CH₂¹³CHCH₃	45.30(20)	9304.15(5)	8107.14(5)
CH₂CH¹³CH₃	46.17(20)	9047.94(5)	7932.98(5)
c-CHDCHCH₃	40.22(20)	9040.09(5)	7729.65(5)
sym-CH₂CHCH₂D	40.59(20)	9066.99(5)	7765.98(5)
asy-CH₂CHCH₂D	43.26(20)	8659.02(5)	7718.11(5)
sym-CH₂CDCH₂D	34.06	9058.28	7483.72	66044
t-CDHCDCH₃	33.71	9038.74	7451.01
c-CDHCHCH₂D	35.71	8821.61	7397.33
asy-CH₂CDCH₂D	36.18	8654.53	7449.49
c-CHDCDCH₃	37.96	8546.43	7289.36
asy-CH₂CHCD₂H	38.22	8469.44	7395.45
cis-asy-CDHCHCH₂D	38.20	8411.37	7340.45
CD₂CHCH₃	39.82	8347.03	7203.75
t-sym-CHDCHCH₂D	40.36	8324.23	7210.10
sym-CH₂CHCHD₂	39.73	8111.44	7370.87
t-asy-CHDCHCH₂D	43.04	7976.26	7164.02

C₃H₆ - Cyclopropane

Molecular constants for cyclopropane
Parameter		Ref.		Ref.		Ref.
A [MHz]	18835.662(18)	87019		^a		^b
B [MHz]	16370.2703(70)		20093.317(30)		13832.06(60)
C [MHz]	11409.2285(67)		12522.3(90)
Δ_J [MHz]	0.011 246(12)		0.028 985(29)		0.011 48(51)
Δ_JK [MHz]	0.005 087(35)		-0.037 447(87)
Δ_K [MHz]	0.007 06(12)
δ_J [MHz]	0.003 0280(79)
δ_K [MHz]	0.005 561(27)

^a J. Pliva and J.W.C. Johns, Can. J. Phys. 62, 139 (1984).

^b A.H. Nielsen, S.J. Daunt, and G.W. Halsey, J. Mol. Spectrosc. 81, 494 (1980).

NIST Physical Measurement Laboratory