Isotopes of bromine

Bromine (₃₅Br) has two stable isotopes, ⁷⁹Br and ⁸¹Br, with nearly equal natural abundance, and 32 known artificial radioisotopes from ⁶⁸Br to ¹⁰¹Br, the most stable of which is ⁷⁷Br, with a half-life of 57.04 hours. This is followed by ⁸²Br at 35.282 hours and ⁷⁶Br at 16.2 hours; the most stable isomer is ^80mBr with the half-life of 4.4205 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. Radiobromine has the advantage that organobromides are more stable than analogous organoiodides, and that it is not uptaken by the thyroid like iodine.

List of isotopes

|-id=Bromine-67 | ⁶⁷Br | style="text-align:right" | 35 | style="text-align:right" | 32 | | | | | | | |-id=Bromine-68 | ⁶⁸Br | style="text-align:right" | 35 | style="text-align:right" | 33 | 67.95836(28)# | ~35&nbsp;ns | p? | ⁶⁷Se | 3+# | | |-id=Bromine-69 | ⁶⁹Br | style="text-align:right" | 35 | style="text-align:right" | 34 | 68.950338(45) | <19&nbsp;ns | p | ⁶⁸Se | (5/2−) | | |-id=Bromine-70 | rowspan=2|⁷⁰Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 35 | rowspan=2|69.944792(16) | rowspan=2|78.8(3)&nbsp;ms | β⁺ | ⁷⁰Se | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺, p? | ⁶⁹As |-id=Bromine-70m | rowspan=2 style="text-indent:1em" | ^70mBr | rowspan=2 colspan="3" style="text-indent:2em" | 2292.3(8)&nbsp;keV | rowspan=2|2.16(5)&nbsp;s | β⁺ | ⁷⁰Se | rowspan=2|9+ | rowspan=2| | rowspan=2| |- | β⁺, p? | ⁶⁹As |-id=Bromine-71 | ⁷¹Br | style="text-align:right" | 35 | style="text-align:right" | 36 | 70.9393422(58) | 21.4(6)&nbsp;s | β⁺ | ⁷¹Se | (5/2)− | | |-id=Bromine-72 | ⁷²Br | style="text-align:right" | 35 | style="text-align:right" | 37 | 71.9365946(11) | 78.6(24)&nbsp;s | β⁺ | ⁷²Se | 1+ | | |-id=Bromine-72m | rowspan=2 style="text-indent:1em" | ^72mBr | rowspan=2 colspan="3" style="text-indent:2em" | 100.76(15)&nbsp;keV | rowspan=2|10.6(3)&nbsp;s | IT | ⁷²Br | rowspan=2|(3−) | rowspan=2| | rowspan=2| |- | β⁺? | ⁷²Se |-id=Bromine-73 | ⁷³Br | style="text-align:right" | 35 | style="text-align:right" | 38 | 72.9316734(72) | 3.4(2)&nbsp;min | β⁺ | ⁷³Se | 1/2− | | |-id=Bromine-74 | ⁷⁴Br | style="text-align:right" | 35 | style="text-align:right" | 39 | 73.9299103(63) | 25.4(3)&nbsp;min | β⁺ | ⁷⁴Se | (0−) | | |-id=Bromine-74m | style="text-indent:1em" | ^74mBr | colspan="3" style="text-indent:2em" | 13.58(21)&nbsp;keV | 46(2)&nbsp;min | β⁺ | ⁷⁴Se | 4+ | | |- | rowspan=2|⁷⁵Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 40 | rowspan=2|74.9258106(46) | rowspan=2|96.7(13)&nbsp;min | β⁺ (76%) | ⁷⁵Se | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | EC (24%) | ⁷⁵Se |- | rowspan=2|⁷⁶Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 41 | rowspan=2|75.924542(10) | rowspan=2|16.2(2)&nbsp;h | β⁺ (57%) | ⁷⁶Se | rowspan=2|1− | rowspan=2| | rowspan=2| |- | EC (43%) | ⁷⁶Se |-id=Bromine-76m | rowspan=2 style="text-indent:1em" | ^76mBr | rowspan=2 colspan="3" style="text-indent:2em" | 102.58(3)&nbsp;keV | rowspan=2|1.31(2)&nbsp;s | IT (>99.4%) | ⁷⁶Br | rowspan=2|(4)+ | rowspan=2| | rowspan=2| |- | β⁺ (<0.6%) | ⁷⁶Se |- | rowspan=2|⁷⁷Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 42 | rowspan=2|76.9213792(30) | rowspan=2|57.04(12)&nbsp;h | EC (99.3%) | ⁷⁷Se | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | β⁺ (0.7%) | ⁷⁷Se |-id=Bromine-77m | style="text-indent:1em" | ^77mBr | colspan="3" style="text-indent:2em" | 105.86(8)&nbsp;keV | 4.28(10)&nbsp;min | IT | ⁷⁷Br | 9/2+ | | |-id=Bromine-78 | rowspan=2|⁷⁸Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 43 | rowspan=2|77.9211459(38) | rowspan=2|6.45(4)&nbsp;min | β⁺ (>99.99%) | ⁷⁸Se | rowspan=2|1+ | rowspan=2| | rowspan=2| |- | β^− (<0.01%) | ⁷⁸Kr |-id=Bromine-78m | style="text-indent:1em" | ^78mBr | colspan="3" style="text-indent:2em" | 180.89(13)&nbsp;keV | 119.4(10)&nbsp;μs | IT | ⁷⁸Br | (4+) | | |-id=Bromine-79 | ⁷⁹Br | style="text-align:right" | 35 | style="text-align:right" | 44 | 78.9183376(11) | colspan=3 align=center|Stable | 3/2− | 0.5065(9) | |-id=Bromine-79m | style="text-indent:1em" | ^79mBr | colspan="3" style="text-indent:2em" | 207.61(9)&nbsp;keV | 4.85(4)&nbsp;s | IT | ⁷⁹Br | 9/2+ | | |-id=Bromine-80 | rowspan=2|⁸⁰Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 45 | rowspan=2|79.9185298(11) | rowspan=2|17.68(2)&nbsp;min | β^− (91.7%) | ⁸⁰Kr | rowspan=2|1+ | rowspan=2| | rowspan=2| |- | β⁺ (8.3%) | ⁸⁰Se |-id=Bromine-80m | style="text-indent:1em" | ^80mBr | colspan="3" style="text-indent:2em" | 85.843(4)&nbsp;keV | 4.4205(8)&nbsp;h | IT | ⁸⁰Br | 5− | | |-id=Bromine-81 | ⁸¹Br | style="text-align:right" | 35 | style="text-align:right" | 46 | 80.9162882(10) | colspan=3 align=center|Stable | 3/2− | 0.4935(9) | |-id=Bromine-81m | style="text-indent:1em" | ^81mBr | colspan="3" style="text-indent:2em" | 536.20(9)&nbsp;keV | 34.6(28)&nbsp;μs | IT | ⁸¹Br | 9/2+ | | |-id=Bromine-82 | ⁸²Br | style="text-align:right" | 35 | style="text-align:right" | 47 | 81.9168018(10) | 35.282(7)&nbsp;h | β^− | ⁸²Kr | 5− | | |-id=Bromine-82m | rowspan=2 style="text-indent:1em" | ^82mBr | rowspan=2 colspan="3" style="text-indent:2em" | 45.9492(10)&nbsp;keV | rowspan=2|6.13(5)&nbsp;min | IT (97.6%) | ⁸²Br | rowspan=2|2− | rowspan=2| | rowspan=2| |- | β^− (2.4%) | ⁸²Kr |-id=Bromine-83 | ⁸³Br | style="text-align:right" | 35 | style="text-align:right" | 48 | 82.9151753(41) | 2.374(4)&nbsp;h | β^− | ⁸³Kr | 3/2− | | |-id=Bromine-83m | style="text-indent:1em" | ^83mBr | colspan="3" style="text-indent:2em" | 3069.2(4)&nbsp;keV | 729(77)&nbsp;ns | IT | ⁸³Br | (19/2−) | | |-id=Bromine-84 | ⁸⁴Br | style="text-align:right" | 35 | style="text-align:right" | 49 | 83.9165136(17) | 31.76(8)&nbsp;min | β^− | ⁸⁴Kr | 2− | | |-id=Bromine-84m1 | style="text-indent:1em" | ^84m1Br | colspan="3" style="text-indent:2em" | 193.6(15)&nbsp;keV | 6.0(2)&nbsp;min | β^− | ⁸⁴Kr | (6)− | | |-id=Bromine-84m2 | style="text-indent:1em" | ^84m2Br | colspan="3" style="text-indent:2em" | 408.2(4)&nbsp;keV | <140&nbsp;ns | IT | ⁸⁴Br | 1+ | | |-id=Bromine-85 | ⁸⁵Br | style="text-align:right" | 35 | style="text-align:right" | 50 | 84.9156458(33) | 2.90(6)&nbsp;min | β^− | ^85m1Kr | 3/2− | | |-id=Bromine-86 | ⁸⁶Br | style="text-align:right" | 35 | style="text-align:right" | 51 | 85.9188054(33) | 55.1(4)&nbsp;s | β^− | ⁸⁶Kr | (1−) | | |-id=Bromine-87 | rowspan=2|⁸⁷Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 52 | rowspan=2|86.9206740(34) | rowspan=2|55.68(12)&nbsp;s | β^− (97.40%) | ⁸⁷Kr | rowspan=2|5/2− | rowspan=2| | rowspan=2| |- | β^−, n (2.60%) | ⁸⁶Kr |-id=Bromine-88 | rowspan=2|⁸⁸Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 53 | rowspan=2|87.9240833(34) | rowspan=2|16.34(8)&nbsp;s | β^− (93.42%) | ⁸⁸Kr | rowspan=2|(1−) | rowspan=2| | rowspan=2| |- | β^−, n (6.58%) | ⁸⁷Kr |-id=Bromine-88m | style="text-indent:1em" | ^88mBr | colspan="3" style="text-indent:2em" | 270.17(11)&nbsp;keV | 5.51(4)&nbsp;μs | IT | ⁸⁸Br | (4−) | | |-id=Bromine-89 | rowspan=2|⁸⁹Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 54 | rowspan=2|88.9267046(35) | rowspan=2|4.357(22)&nbsp;s | β^− (86.2%) | ⁸⁹Kr | rowspan=2|(3/2−, 5/2−) | rowspan=2| | rowspan=2| |- | β^−, n (13.8%) | ⁸⁸Kr |-id=Bromine-90 | rowspan=2|⁹⁰Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 55 | rowspan=2|89.9312928(36) | rowspan=2|1.910(10)&nbsp;s | β^− (74.7%) | ⁹⁰Kr | rowspan=2| | rowspan=2| | rowspan=2| |- | β^−, n (25.3%) | ⁸⁹Kr |-id=Bromine-91 | rowspan=2|⁹¹Br | rowspan=2 style="text-align:right" | 35 | rowspan=2 style="text-align:right" | 56 | rowspan=2|90.9343986(38) | rowspan=2|543(4)&nbsp;ms | β^− (70.5%) | ⁹¹Kr | rowspan=2|5/2−# | rowspan=2| | rowspan=2| |- | β^−, n (29.5%) | ⁹⁰Kr |-id=Bromine-92 | rowspan=3|⁹²Br | rowspan=3 style="text-align:right" | 35 | rowspan=3 style="text-align:right" | 57 | rowspan=3|91.9396316(72) | rowspan=3|314(16)&nbsp;ms | β^− (66.9%) | ⁹²Kr | rowspan=3|(2−) | rowspan=3| | rowspan=3| |- | β^−, n (33.1%) | ⁹¹Kr |- | β^−, 2n? | ⁹⁰Kr |-id=Bromine-92m1 | style="text-indent:1em" | ^92m1Br | colspan="3" style="text-indent:2em" | 662(1)&nbsp;keV | 88(8)&nbsp;ns | IT | ⁹²Br | | | |-id=Bromine-92m2 | style="text-indent:1em" | ^92m2Br | colspan="3" style="text-indent:2em" | 1138(1)&nbsp;keV | 85(10)&nbsp;ns | IT | ⁹²Br | | | |-id=Bromine-93 | rowspan=3|⁹³Br | rowspan=3 style="text-align:right" | 35 | rowspan=3 style="text-align:right" | 58 | rowspan=3|92.94322(46) | rowspan=3|152(8)&nbsp;ms | β^−, n (64%) | ⁹²Kr | rowspan=3|5/2−# | rowspan=3| | rowspan=3| |- | β^− (36%) | ⁹³Kr |- | β^−, 2n? | ⁹¹Kr |-id=Bromine-94 | rowspan=3|⁹⁴Br | rowspan=3 style="text-align:right" | 35 | rowspan=3 style="text-align:right" | 59 | rowspan=3|93.94885(22)# | rowspan=3|70(20)&nbsp;ms | β^−, n (68%) | ⁹³Kr | rowspan=3|2−# | rowspan=3| | rowspan=3| |- | β^− (32%) | ⁹⁴Kr |- | β^−, 2n? | ⁹²Kr |-id=Bromine-94m | style="text-indent:1em" | ^94mBr | colspan="3" style="text-indent:2em" | 294.6(5)&nbsp;keV | 530(15)&nbsp;ns | IT | ⁹⁴Br | | | |-id=Bromine-95 | rowspan=3|⁹⁵Br | rowspan=3 style="text-align:right" | 35 | rowspan=3 style="text-align:right" | 60 | rowspan=3|94.95293(32)# | rowspan=3|80#&nbsp;ms [>300&nbsp;ns] | β^−? | ⁹⁵Kr | rowspan=3|5/2−# | rowspan=3| | rowspan=3| |- | β^−, n? | ⁹⁴Kr |- | β^−, 2n? | ⁹³Kr |-id=Bromine-95m | style="text-indent:1em" | ^95mBr | colspan="3" style="text-indent:2em" | 537.9(5)&nbsp;keV | 6.8(10)&nbsp;μs | IT | ⁹⁵Br | | | |-id=Bromine-96 | rowspan=3|⁹⁶Br | rowspan=3 style="text-align:right" | 35 | rowspan=3 style="text-align:right" | 61 | rowspan=3|95.95898(32)# | rowspan=3|20#&nbsp;ms [>300&nbsp;ns] | β^−? | ⁹⁶Kr | rowspan=3| | rowspan=3| | rowspan=3| |- | β^−, n? | ⁹⁵Kr |- | β^−, 2n? | ⁹⁴Kr |-id=Bromine-96m | style="text-indent:1em" | ^96mBr | colspan="3" style="text-indent:2em" | 311.5(5)&nbsp;keV | 3.0(9)&nbsp;μs | IT | ⁹⁶Br | | | |-id=Bromine-97 | rowspan=3|⁹⁷Br | rowspan=3 style="text-align:right" | 35 | rowspan=3 style="text-align:right" | 62 | rowspan=3|96.96350(43)# | rowspan=3|40# ms [>300&nbsp;ns] | β^−? | ⁹⁷Kr | rowspan=3|5/2−# | rowspan=3| | rowspan=3| |- | β^−, n? | ⁹⁶Kr |- | β^−, 2n? | ⁹⁵Kr |-id=Bromine-98 | rowspan=3|⁹⁸Br | rowspan=3 style="text-align:right" | 35 | rowspan=3 style="text-align:right" | 63 | rowspan=3|97.96989(43)# | rowspan=3|15#&nbsp;ms [>400&nbsp;ns] | β^−? | ⁹⁸Kr | rowspan=3| | rowspan=3| | rowspan=3| |- | β^−, n? | ⁹⁷Kr |- | β^−, 2n? | ⁹⁶Kr |-id=Bromine-99 | ⁹⁹Br | style="text-align:right" | 35 | style="text-align:right" | 64 | | | | | | | |-id=Bromine-100 | ¹⁰⁰Br | style="text-align:right" | 35 | style="text-align:right" | 65 | | | | | | | |-id=Bromine-101 | ¹⁰¹Br | style="text-align:right" | 35 | style="text-align:right" | 66 | | | | | | |

Bromine-75

Bromine-75 has a half-life of 97&nbsp;minutes. This isotope undergoes positron emission rather than electron capture about 76% of the time, so it was used for diagnosis and positron emission tomography (PET) in the 1980s. However, its decay product, selenium-75, produces secondary radioactivity with a longer half-life of around 120&nbsp;days.

Bromine-76

Bromine-76 has a half-life of 16.2&nbsp;hours. While its decay is more energetic than ⁷⁵Br and has a lower yield of positrons, about 57% of decays, 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.

Bromine-77

Bromine-77 is the most stable radioisotope of bromine, with a half-life of 57.04&nbsp;hours. Although β⁺ decay is possible for this isotope, about 99.3% of decays are by electron capture. Despite its complex emission spectrum, featuring strong gamma-ray emissions at 239, 297, 521, and 579&nbsp;keV, ⁷⁷Br was used in SPECT imaging in the 1970s. However, except for longer-term tracing, this is no longer considered practical due to the difficult collimator requirements and the proximity of the 521&nbsp;keV line to the 511&nbsp;keV annihilation radiation related to the β⁺ decay. The Auger electrons emitted during decay are nevertheless well-suited for radiotherapy, and ⁷⁷Br can possibly be paired with the imaging-suited ⁷⁶Br (produced as an impurity in common synthesis routes) for this application.

See also

Daughter products other than bromine

• Isotopes of krypton
• Isotopes of selenium
• Isotopes of arsenic

References