Isotopes of bromine (35Br)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
75Br synth 96.7 min β+ 75Se
76Br synth 16.2 h β+ 76Se
77Br synth 57.04 h β+ 77Se
79Br 50.6% stable
80mBr synth 4.4205 h IT 80Br
81Br 49.4% stable
82Br synth 35.282 h β− 82Kr
Standard atomic weight Ar°(Br)
  • [79.901, 79.907]
  • 79.904±0.003 (abridged)[2][3]

Bromine (35Br) has two stable isotopes, 79Br and 81Br, and 32 known radioisotopes, the most stable of which is 77Br, with a half-life of 57.036 hours.

Like the radioactive isotopes of iodine, radioisotopes of bromine, collectively radiobromine, can be used to label biomolecules for nuclear medicine; for example, the positron emitters 75Br and 76Br can be used for positron emission tomography.[4][5] Radiobromine has the advantage that organobromides are more stable than analogous organoiodides, and that it is not uptaken by the thyroid like iodine.[6]

List of isotopes

Nuclide
[n 1] 		Z N Isotopic mass (Da)[7]
[n 2][n 3] 		Half-life[1]
 Decay
mode[1]
[n 4] 		Daughter
isotope
[n 5][n 6] 		Spin and
parity[1]
[n 7][n 8] 		Natural abundance (mole fraction)
Excitation energy Normal proportion[1] Range of variation
68Br[8] 35 33 67.95836(28)# ~35 ns p? 67Se 3+#
69Br 35 34 68.950338(45) <19 ns[8] p 68Se (5/2−)
70Br 35 35 69.944792(16) 78.8(3) ms β+ 70Se 0+
β+, p? 69As
70mBr 2292.3(8) keV 2.16(5) s β+ 70Se 9+
β+, p? 69As
71Br 35 36 70.9393422(58) 21.4(6) s β+ 71Se (5/2)−
72Br 35 37 71.9365946(11) 78.6(24) s β+ 72Se 1+
72mBr 100.76(15) keV 10.6(3) s IT 72Br (3-)
β+? 72Se
73Br 35 38 72.9316734(72) 3.4(2) min β+ 73Se 1/2−
74Br 35 39 73.9299103(63) 25.4(3) min β+ 74Se (0−)
74mBr 13.58(21) keV 46(2) min β+ 74Se 4+
75Br 35 40 74.9258106(46) 96.7(13) min β+ (76%)[6] 75Se 3/2−
EC (24%) 76Se
76Br 35 41 75.924542(10) 16.2(2) h β+ (57%)[6] 76Se 1−
EC (43%) 76Se
76mBr 102.58(3) keV 1.31(2) s IT (>99.4%) 76Br (4)+
β+ (<0.6%) 76Se
77Br 35 42 76.9213792(30) 57.04(12) h EC (99.3%)[9] 77Se 3/2−
β+ (0.7%) 77Se
77mBr 105.86(8) keV 4.28(10) min IT 77Br 9/2+
78Br 35 43 77.9211459(38) 6.45(4) min β+ (>99.99%) 78Se 1+
β− (<0.01%) 78Kr
78mBr 180.89(13) keV 119.4(10) μs IT 78Br (4+)
79Br 35 44 78.9183376(11) Stable 3/2− 0.5065(9)
79mBr 207.61(9) keV 4.85(4) s IT 79Br 9/2+
80Br 35 45 79.9185298(11) 17.68(2) min β− (91.7%) 80Kr 1+
β+ (8.3%) 80Se
80mBr 85.843(4) keV 4.4205(8) h IT 80Br 5−
81Br 35 46 80.9162882(10) Stable 3/2− 0.4935(9)
81mBr 536.20(9) keV 34.6(28) μs IT 81Br 9/2+
82Br 35 47 81.9168018(10) 35.282(7) h β− 82Kr 5−
82mBr 45.9492(10) keV 6.13(5) min IT (97.6%) 82Br 2−
β− (2.4%) 82Kr
83Br 35 48 82.9151753(41) 2.374(4) h β− 83Kr 3/2−
83mBr 3069.2(4) keV 729(77) ns IT 83Br (19/2−)
84Br 35 49 83.916496(28) 31.76(8) min β− 84Kr 2−
84m1 310(100) keV 6.0(2) min β− 84Kr (6)−
84m2Br 408.2(4) keV <140 ns IT 84Br 1+
85Br 35 50 84.9156458(33) 2.90(6) min β− 85Kr 3/2−
86Br 35 51 85.9188054(33) 55.1(4) s β− 86Kr (1−)
87Br 35 52 86.9206740(34) 55.68(12) s β− (97.40%) 87Kr 5/2−
β−, n (2.60%) 86Kr
88Br 35 53 87.9240833(34) 16.34(8) s β− (93.42%) 88Kr (1−)
β−, n (6.58%) 87Kr
88mBr 270.17(11) keV 5.51(4) μs IT 88Br (4−)
89Br 35 54 88.9267046(35) 4.357(22) s β− (86.2%) 89Kr (3/2−, 5/2−)
β−, n (13.8%) 88Kr
90Br 35 55 89.9312928(36) 1.910(10) s β− (74.7%) 90Kr
β−, n (25.3%) 89Kr
91Br 35 56 90.9343986(38) 543(4) ms β− (70.5%) 91Kr 5/2−#
β−, n (29.5%) 90Kr
92Br 35 57 91.9396316(72) 314(16) ms β− (66.9%) 92Kr (2−)
β−, n (33.1%) 91Kr
β−, 2n? 90Kr
92m1Br 662(1) keV 88(8) ns IT 92Br
92m2Br 1138(1) keV 85(10) ns IT 92Br
93Br 35 58 92.94322(46) 152(8) ms β−, n (64%) 92Kr 5/2−#
β− (36%) 93Kr
β−, 2n? 91Kr
94Br 35 59 93.94885(22)# 70(20) ms β−, n (68%) 93Kr 2−#
β− (32%) 94Kr
β−, 2n? 92Kr
94mBr 294.6(5) keV 530(15) ns IT 94Br
95Br 35 60 94.95293(32)# 80# ms [>300 ns] β−? 95Kr 5/2−#
β−, n? 94Kr
β−, 2n? 93Kr
95mBr 537.9(5) keV 6.8(10) μs IT 95Br
96Br 35 61 95.95898(32)# 20# ms [>300 ns] β−? 96Kr
β−, n? 95Kr
β−, 2n? 94Kr
96mBr 311.5(5) keV 3.0(9) μs IT 95Br
97Br 35 62 96.96350(43)# 40# ms [>300 ns] β−? 97Kr 5/2−#
β−, n? 96Kr
β−, 2n? 95Kr
98Br 35 63 97.96989(43)# 15# ms [>400 ns] β−? 98Kr
β−, n? 97Kr
β−, 2n? 96Kr
101Br[10] 35 66
This table header & footer:
  1. ^ mBr – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ Modes of decay:
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  5. ^ Bold italics symbol as daughter – Daughter product is nearly stable.
  6. ^ Bold symbol as daughter – Daughter product is stable.
  7. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  8. ^ # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

Bromine-75

Bromine-75 has a half-life of 97 minutes.[11] This isotope undergoes β+ decay rather than electron capture about 76% of the time,[6] so it was used for diagnosis and positron emission tomography (PET) in the 1980s.[4] However, its decay product, selenium-75, produces secondary radioactivity with a longer half-life of 120.4 days.[6][4]

Bromine-76

Bromine-76 has a half-life of 16.2 hours.[11] While its decay is more energetic than 75Br and has lower yield of positrons (about 57% of decays),[6] bromine-76 has been preferred in PET applications since the 1980s because of its longer half-life and easier synthesis, and because its decay product, 76Se, is not radioactive.[5]

Bromine-77

Bromine-77 is the most stable radioisotope of bromine, with a half-life of 57 hours.[11] Although β+ decay is possible for this isotope, about 99.3% of decays are by electron capture.[9] Despite its complex emission spectrum, featuring strong gamma-ray emissions at 239, 297, 521, and 579 keV,[12] 77Br was used in SPECT imaging in the 1970s,[13] but except for longer-term tracing,[6] this is no longer considered practical due to the difficult collimator requirements and the proximity of the 521 keV line to the 511 keV annihilation radiation related to the β+ decay.[13] However, the auger electrons emitted during decay are well-suited for radiotherapy, and it can possibly be paired with the imaging-suited 76Br (produced as an impurity in common synthesis routes) for this application.[4][13]

References

  1. ^ a b c d e Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ "Standard Atomic Weights: Bromine". CIAAW. 2011.
  3. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ^ a b c d Coenen, Heinz H.; Ermert, Johannes (January 2021). "Expanding PET-applications in life sciences with positron-emitters beyond fluorine-18". Nuclear Medicine and Biology. 92: 241–269. doi:10.1016/j.nucmedbio.2020.07.003.
  5. ^ a b Welch, Michael J.; Mcelvany, Karen D. (1 October 1983). "Radionuclides of Bromine for Use in Biomedical Studies". ract. 34 (1–2): 41–46. doi:10.1524/ract.1983.34.12.41.
  6. ^ a b c d e f g Lambert, F.; Slegers, G.; Hermanne, α.; Mertens, J. (1 June 1994). "Production and Purification of 77 Br Suitable for Labeling Monoclonal Antibodies Used in Tumor Imaging". ract. 65 (4): 223–226. doi:10.1524/ract.1994.65.4.223.
  7. ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
  8. ^ a b Wimmer, K.; et al. (2019). "Discovery of 68Br in secondary reactions of radioactive beams". Physics Letters B. 795: 266–270. arXiv:1906.04067. Bibcode:2019PhLB..795..266W. doi:10.1016/j.physletb.2019.06.014. S2CID 182953245.
  9. ^ a b Kassis, A. I.; Adelstein, S. J.; Haydock, C.; Sastry, K. S. R.; McElvany, K. D.; Welch, M. J. (May 1982). "Lethality of Auger Electrons from the Decay of Bromine-77 in the DNA of Mammalian Cells" (PDF). Radiation Research. 90 (2): 362. doi:10.2307/3575714. ISSN 0033-7587.
  10. ^ Sumikama, T.; et al. (2021). "Observation of new neutron-rich isotopes in the vicinity of Zr110". Physical Review C. 103 (1): 014614. Bibcode:2021PhRvC.103a4614S. doi:10.1103/PhysRevC.103.014614. hdl:10261/260248. S2CID 234019083.
  11. ^ a b c Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  12. ^ Singh, Balraj; Nica, Ninel (May 2012). "Nuclear Data Sheets for A = 77". Nuclear Data Sheets. 113 (5): 1115–1314. doi:10.1016/j.nds.2012.05.001.
  13. ^ a b c Amjed, N.; Kaleem, N.; Wajid, A.M.; Naz, A.; Ahmad, I. (January 2024). "Evaluation of the cross section data for the low and medium energy cyclotron production of 77Br radionuclide". Radiation Physics and Chemistry. 214: 111286. doi:10.1016/j.radphyschem.2023.111286.
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