Carbon-13

Properties and data of the isotope ¹³C.

Contents

General Data

Parent Nuclides

NMR Data

Isotones und Isobares

Literature

Carbon-13 - ¹³C or C-13 - is a natural, stable isotope of the chemical element carbon, whose atomic nucleus consists of six protons and seven neutrons. As one of the environmental isotopes, it accounts for about 1.1% of all natural carbon on Earth.

Pure carbon-13 for commercial use - particularly for the chemical synthesis of ¹³ C-labeled compounds - must be enriched due to its natural abundance of approximately one 1%. In principle, various techniques or methods such as thermal diffusion, chemical exchange, gas diffusion as well as laser and cryogenic distillation are available to separate C-13 from the main component C-12 of natural carbon.

At present, however, only the cryogenic distillation of methane or carbon monoxide is an economically viable industrial production technology, although such carbon-13 production facilities represent a significant investment. Cryogenic distillation columns more than 100 meters high are required to separate the compounds containing carbon-12 or carbon-13. The world's largest reported commercial C-13 plant (CIL plant in Ohio) has a production capacity of approximately 420 kg of carbon-13 per year (2019). In this method, natural carbon monoxide (CO) is liquefied at a very low temperature and then distilled through special stainless steel columns several kilometers long. In comparison, a 1969 pilot plant for the cryogenic distillation of carbon monoxide at Los Alamos Scientific Laboratories (USA) was able to produce about 4 kg of carbon-13 annually.

See also: List of individual Carbon isotopes (and general data sources).

General data

Name of the isotope:Carbon-13; C-13Symbol:¹³C or 136CMass number A:13 (= number of nucleons)Atomic number Z:6 (= number of protons)Neutrons N:7Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.1666666666667 (= neutron-proton ratio)Neutron excess (N-Z):1Isotopic mass:13.003354835(2) u (atomic weight of Carbon-13)Nuclide mass:13.0000634 u (calculated nuclear mass without electrons)Mass excess:3.12501 MeVMass defect:0.104249769 u (per nucleus)Nuclear binding energy:97.10803432 MeV (per nucleus)
7.46984879 MeV (average binding energy per nucleon)Separation energy:S_N = 4.94631(0) MeV (first neutron)
S_P = 17.5334(13) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)1/2-Isobaric spin: 1/2Magnetic dipole moment:μ(μ_N) = + 0.702369(4)Charge radius:2.4614(34) femtometer fmMatter radius:3.324 femtometer fmMirror nucleus:Nitrogen-13Year of discovery:1929

Parent Nuclides

Direct parent isotopes are: ¹³B, ¹³N.

Occurrence

Comparison of the natural Carbon isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Carbon Isotopic mixture	12.011 u	100 %
Isotope ¹²C	12.00000000000 u	98.94 % [98.84 - 99.04 %]	stable	0+
Isotope ¹⁴C	14.003241988(4) u	[trace]	5700(30) a	0+
Isotope ¹³C	13.003354835(2) u	1.06 % [0.96 - 1.16 %]	stable	1/2-

NMR data

Nuclear magnetic properties and parameters of the NMR active Nuclide ¹³C

Isotope:¹³C-NMRQuantity:1.06 % [0.96 - 1.16 %]Spin:1/2-Nuclearmagnetic moment
μ/μ_N:+ 0.702369(4)Gyromagnetic ratio γ:6.728284 · 10⁷ rad T^-1 s^-1
10.70840 MHz T^-1Nuclear g-factor:g_l = 1.404738Resonance frequency:v₀ = 10.7084 MHz at 1 TRelative Sensitivity:[related to ¹H = 1.000]:
0.01591 (H₀ = const.)
0.2515 (v₀ = const.)
0.000170 (at natural abundance)
relative receptivity as compared to ¹³C:
1.00 (at natural abundance)Reference compound:
(conditions)Solution of 1% Tetramethylsilane (Si(CH₃)₄) in Chloroform-d (CDCl₃).Frequency ratio:Ξ(¹³C) = 25.145020 % [based on the reference substance]

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 7) and isobaric (same nucleon number A = 13) with Carbon-13. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 7	Isobar A = 13
2	⁹He
3	¹⁰Li	¹³Li
4	¹¹Be	¹³Be
5	¹²B	¹³B
6	¹³C	¹³C
7	¹⁴N	¹³N
8	¹⁵O	¹³O
9	¹⁶F	¹³F
10	¹⁷Ne
11	¹⁸Na
12	¹⁹Mg
13	²⁰Al

External data and identifiers

CAS:14762-74-4InChI Key:OKTJSMMVPCPJKN-OUBTZVSYSA-NSMILES:[13C]Adopted Levels, Gammas:NuDat 13C

Literature and References

[1] - Darren Brown, John Greene:
10th international symposium on the synthesis and applications of isotopes and isotopically labelled compounds.
In: Journal of Labelled Compounds and Radiophamaceuticals, (2010), DOI 10.1002/jlcr.1775.

[2] - Hu-LinLi, Yong-Lin Ju, Liang-JunLi, Da-GangXu:
Separation of isotope ¹³C using high-performance structured packing.
In: Chemical Engineering and Processing: Process Intensification, (2010), DOI 10.1016/j.cep.2010.02.001.