Copper (₂₉Cu) has two stable isotopes, ⁶³Cu and ⁶⁵Cu, along with 27 radioisotopes. The most stable radioisotope is ⁶⁷Cu with a half-life of 61.83 hours, while the least stable is ⁵⁴Cu with a half-life of approximately 75 ns. Most have half-lives under a minute. Unstable copper isotopes with atomic masses below 63 tend to undergo β⁺ decay, while isotopes with atomic masses above 65 tend to undergo β⁻ decay. ⁶⁴Cu decays by both β⁺ and β⁻.^[4]

⁶⁸Cu, ⁶⁹Cu, ⁷¹Cu, ⁷²Cu, and ⁷⁶Cu each have one metastable isomer. ⁷⁰Cu has two isomers, making a total of 7 distinct isomers. The most stable of these is ^68mCu with a half-life of 3.75 minutes. The least stable is ^69mCu with a half-life of 360 ns.^[4]

Copper nuclear magnetic resonance

Both stable isotopes of copper (⁶³Cu and ⁶⁵Cu) have nuclear spin of -3/2, and thus produce nuclear magnetic resonance spectra, although the spectral lines are broad due to quadrupolar broadening. ⁶³Cu is the more sensitive nucleus while ⁶⁵Cu yields very slightly narrower signals. Usually though ⁶³Cu NMR is preferred.^[5]

List of isotopes

Medical applications

Copper offers a relatively large number of radioisotopes that are potentially suitable for use in nuclear medicine.

There is a growing interest in the use of ⁶⁴Cu, ⁶²Cu, ⁶¹Cu, and ⁶⁰Cu for diagnostic purposes and ⁶⁷Cu and ⁶⁴Cu for targeted radiotherapy. For example, ⁶⁴Cu has a longer half-life than most positron-emitters (12.7 hours) and is thus ideal for diagnostic PET imaging of biological molecules.^[6]

References

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
• "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
• Half-life, spin, and isomer data selected from the following sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
• Application of Copper radioisotopes in Medicine (Review Paper):
  • Pejman Rowshanfarzad; Mahsheed Sabet; AmirReza Jalilian; Mohsen Kamalidehghan (2006). "An overview of copper radionuclides and production of ⁶¹Cu by proton irradiation of ^natZn at a medical cyclotron". Applied Radiation and Isotopes. 64 (12): 1563–1573. doi:10.1016/j.apradiso.2005.11.012. PMID 16377202.