View source for Pertechnetate

{{Short description|Chemical compound or ion}}
[[Image:Pertechnetate1.svg|thumb|right|200px|The structure of the technetate(VII) ion]]
The '''pertechnetate''' ion ({{IPAc-en|p|@r|'|t|E|k|n|@|t|ei|t}})<ref>{{MW|pertechnetate}}</ref> is an [[oxyanion]] with the chemical formula {{chem|TcO|4|-}}. It is often used as a convenient water-soluble source of isotopes of the radioactive element [[technetium]] (Tc). In particular it is used to carry the [[Technetium-99m|<sup>99m</sup>Tc]] isotope (half-life 6 hours) which is commonly used in [[nuclear medicine]] in several nuclear scanning procedures.

Pertechnetate is poorly hydrated as [TcO<sub>4</sub>(H<sub>2</sub>O)<sub>n</sub>]<sup>−</sup> and [TcO<sub>4</sub>(H<sub>2</sub>O)<sub>n-m</sub>]<sup>−</sup>[H<sub>3</sub>O]<sup>+</sup><sub>m</sub> (n = 1–50, m = 1–4) clusters that have been demonstrated by simulation with DFT. First hydration shell of TcO<sub>4</sub><sup>−</sup> is asymmetric and contains no more than 7 water molecules. Only three of the four oxygen atoms of TcO<sub>4</sub><sup>−</sup> form hydrogen bonds with water molecules.<ref>{{Cite journal |last=Ustynyuk |first=Yuri A. |last2=Gloriozov |first2=Igor P. |last3=Zhokhova |first3=Nelly I. |last4=German |first4=Konstantin E. |last5=Kalmykov |first5=Stepan N. |date=November 2021 |title=Hydration of the pertechnetate anion. DFT study |url=https://doi.org/10.1016/j.molliq.2021.117404 |journal=Journal of Molecular Liquids |volume=342 |pages=117404 |doi=10.1016/j.molliq.2021.117404 |issn=0167-7322|url-access=subscription }}</ref>

A '''technetate(VII)''' salt is a [[chemical compound|compound]] containing this ion. Pertechnetate compounds are salts of [[pertechnetic acid|technetic(VII) acid]]. Pertechnetate is analogous to [[permanganate]] but it has little oxidizing power. Pertechnetate has higher oxidation power than perrhenate.<ref name=weaver17/>

Understanding pertechnetate is important in understanding technetium contamination in the environment and in [[nuclear waste management]].<ref name=weaver17/>

==Chemistry==
{{chem|Tc|O|4|-}} is the starting material for most of the chemistry of technetium. Pertechnetate salts are usually colorless.<ref>Wells, A. F.; Structural Inorganic Chemistry; Clarendon Press: Oxford, Great Britain; 1984; p. 1050.</ref> {{chem|Tc|O|4|-}} is produced by oxidizing technetium with nitric acid or with hydrogen peroxide. The pertechnetate anion is similar to the [[permanganate]] anion but is a weaker [[oxidizing agent]]. It is tetrahedral and diamagnetic. The standard electrode potential for {{chem|Tc|O|4|-}}/{{chem|Tc|O|2}} is only +0.738 V in acidic solution, as compared to +1.695 V for {{chem|Mn|O|4|-}}/{{chem|Mn|O|2}}.<ref name=schwochau>{{cite journal | author = Schwochau, K. | year = 1994 | title = Technetium Radiopharmaceuticals-Fundamentals, Synthesis, Structure, and Development | journal = [[Angew. Chem. Int. Ed. Engl.]] | volume = 33 | pages = 2258–2267 | doi = 10.1002/anie.199422581 | issue = 22}}</ref> Because of its diminished oxidizing power, {{chem|Tc|O|4|-}} is stable in alkaline solution. {{chem|Tc|O|4|-}} is more similar to {{chem|link=Perrhenate|Re|O|4|-}}. Depending on the reducing agent, {{chem|Tc|O|4|-}} can be converted to derivatives containing Tc(VI), Tc(V), and Tc(IV).<ref>''Encyclopædia Britannica: Technetium''</ref> In the absence of strong complexing ligands, {{chem|Tc|O|4|-}} is reduced to a +4 oxidation state via the formation of {{chem|Tc|O|2}} hydrate.<ref name=schwochau />

Some metals like actinides,<ref>{{Cite journal |last=Fedosseev |first=A. M. |last2=Budantseva |first2=N. A. |last3=Grigoriev |first3=M. S. |last4=Guerman |first4=K. E. |last5=Krupa |first5=J.-C. |date=2003-03-01 |title=Synthesis and properties of neptunium(VI,V) and plutonium(VI) pertechnetates |url=https://www.degruyter.com/document/doi/10.1524/ract.91.3.147.19976/html |journal=Radiochimica Acta |language=en |volume=91 |issue=3 |pages=147–152 |doi=10.1524/ract.91.3.147.19976 |issn=2193-3405|url-access=subscription }}</ref>  barium, scandium, yttrium <ref>{{Cite journal |last=Strub |first=Erik |last2=Grödler |first2=Dennis |last3=Zaratti |first3=Daniele |last4=Yong |first4=Clarence |last5=Dünnebier |first5=Lisa |last6=Bazhenova |first6=Sonja |last7=Roca Jungfer |first7=Maximilian |last8=Breugst |first8=Martin |last9=Zegke |first9=Markus |date=2024-05-08 |title=Pertechnetates – A Structural Study Across the Periodic Table |url=https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202400131 |journal=Chemistry – A European Journal |language=en |volume=30 |issue=26 |doi=10.1002/chem.202400131 |issn=0947-6539|doi-access=free |url-access=subscription }}</ref>  or zirconium <ref>{{Cite journal |last=Shohel |first=Mohammad |last2=Bustos |first2=Jenna |last3=Roseborough |first3=Alexander |last4=Nyman |first4=May |date=2023-12-28 |title=Pertechnetate/perrhenate‐capped Zr/Hf‐Dihydroxide Dimers: Elucidating Zr−TcO 4 Co‐Mobility in the Nuclear Fuel Cycle |url=https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202303218 |journal=Chemistry – A European Journal |language=en |doi=10.1002/chem.202303218 |issn=0947-6539}}</ref> may form complex salts with pertechnetate thus  strongly effecting its liquid-liquid extraction behavior.<ref>{{Cite journal |last=Shohel |first=Mohammad |last2=Bustos |first2=Jenna |last3=Roseborough |first3=Alexander |last4=Nyman |first4=May |date=2024-02-16 |title=Pertechnetate/perrhenate‐capped Zr/Hf‐Dihydroxide Dimers: Elucidating Zr−TcO 4 Co‐Mobility in the Nuclear Fuel Cycle |url=https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202303218 |journal=Chemistry – A European Journal |language=en |volume=30 |issue=10 |doi=10.1002/chem.202303218 |issn=0947-6539}}</ref>

==Preparation of <sup>99m</sup>TcO<sub>4</sub>−==
{{Main|technetium-99m generator}}
{{simpleNuclide|Tc|99|m}} is conveniently available in high radionuclidic purity from [[molybdenum]]-99, which decays with 87% probability to {{simpleNuclide|Tc|99|m}}. The subsequent decay of {{simpleNuclide|Tc|99|m}} leads to either {{simpleNuclide|Tc|99}} or {{simpleNuclide|Ru|99}}. {{simpleNuclide|Mo|99}} can be produced in a nuclear reactor via [[irradiation]] of either molybdenum-98 or naturally occurring molybdenum with thermal neutrons, but this is not the method currently in use today. Currently, {{simpleNuclide|Mo|99}} is recovered as a product of the nuclear fission reaction of {{chem|link=Uranium-235|235|U}},<ref>{{cite journal | author = Beasley, T. M., Palmer, H. E., and Nelp, W. B. | year = 1966 | title = Distribution and Excretion of Technetium in Humans |journal = [[Health Physics (journal)|Health Physics]] | volume = 12 | issue = 10 | pages = 1425–1435 | url = http://www.health-physics.com/pt/re/healthphys/abstract.00004032-196610000-00004.htm | doi = 10.1097/00004032-196610000-00004 | pmid=5972440| url-access = subscription }}</ref> separated from other fission products via a multistep process and loaded onto a column of alumina that forms the core of a {{simpleNuclide|Mo|99}}/{{simpleNuclide|Tc|99|m}} radioisotope generator.

As the {{simpleNuclide|Mo|99}} continuously decays to {{simpleNuclide|Tc|99|m}}, the {{simpleNuclide|Tc|99|m}} can be removed periodically (usually daily) by flushing a saline solution (0.15 M NaCl in water) through the alumina column: the more highly charged {{chem|{{simpleNuclide|Mo|99|}}|O|4|2-}} is retained on the column, where it continues to undergo radioactive decay, while the medically useful radioisotope {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} is eluted in the saline. The eluate from the column must be sterile and pyrogen free, so that the Tc drug can be used directly, usually within 12 hours of elution.<ref name=schwochau/> In a few cases, sublimation or solvent extraction may be used.

===Examples===
*A complex that can penetrate the blood–brain barrier is generated by reduction of {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} with tin(II) in the presence of the ligand hexamethylpropylene amine oxime (HMPAO) to form [[Technetium (99mTc) exametazime|TcO-''D,L''-HMPAO]].
*A complex that for imaging the lungs, [[Tc-MAA]], is generated by reduction of {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} with {{chem|link=Tin(II) chloride|Sn|Cl|2}} in the presence of human serum albumin.
*{{chem|[{{simpleNuclide|Tc|99|m}}(OH2)3(CO)3]+}}, which is both water and air stable, is generated by reduction of {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} with carbon monoxide. This compound is a precursor to complexes that can be used in cancer diagnosis and therapy involving DNA-DNA pretargeting.<ref>{{cite journal | author = R. Alberto, R. Schibli, A. Egli, A. P. Schubiger, U. Abram and T. A. Kaden | title = A Novel Organometallic Aqua Complex of Technetium for the Labeling of Biomolecules: Synthesis of {{chem|[|{{simpleNuclide|Tc|99|m}}|(|O|H|2|)|3|(|C|O|)|3|]|+}} from {{chem|[|{{simpleNuclide|Tc|99|m}}|O|4|]|-}} in Aqueous Solution and Its Reaction with a Bifunctional Ligand | year = 1998 | journal = [[J. Am. Chem. Soc.]] | volume = 120 | issue = 31 | pages = 7987–7988 | doi = 10.1021/ja980745t}}</ref>

==Compounds==
{|class="wikitable"
!Formula
!name
!crystal structure
!cell dimensions (Å)
!unit cell volume (Å<sup>3</sup>)
!remarks
!references
|-
|LiTcO<sub>4</sub>
|lithium pertechnetate
|
|
|
|
|<ref name="weaver17"/>
|-
|LiTcO<sub>4</sub>·2H<sub>2</sub>O
|lithium pertechnetate dihydrate
|
|
|
|
|<ref name="weaver17"/>
|-
|LiTcO<sub>4</sub>·3H<sub>2</sub>O
|lithium pertechnetate trihydrate
|
|
|''P''t<sub>3</sub>/''mc''
|
|<ref name="weaver17"/>
|-
|NaTcO<sub>4</sub>
|[[sodium pertechnetate]]
|tetragonal
|a = 5.342, c = 1.874
|338.91
|absorbs water from atmosphere
|<ref name="weaver17">{{cite journal|last1=Weaver|first1=Jamie|last2=Soderquist|first2=Chuck Z.|last3=Washton|first3=Nancy M.|last4=Lipton|first4=Andrew S.|last5=Gassman|first5=Paul L.|last6=Lukens|first6=Wayne W.|last7=Kruger|first7=Albert A.|last8=Wall|first8=Nathalie A.|last9=McCloy|first9=John S.|title=Chemical Trends in Solid Alkali Pertechnetates|journal=Inorganic Chemistry|volume=56|issue=5|pages=2533–2544|date=21 February 2017|doi=10.1021/acs.inorgchem.6b02694|pmid=28221786|doi-access=free}}</ref>
|-
|NaTcO<sub>4</sub>·H<sub>2</sub>O
|sodium pertechnetate monohydrate
|
|
|
|
|<ref name="weaver17"/>
|-
|NaTcO<sub>4</sub>·2H<sub>2</sub>O
|sodium pertechnetate dihydrate
|
|
|
|
|<ref name="weaver17"/>
|-
|NaTcO<sub>4</sub>·4H<sub>2</sub>O
|sodium pertechnetate tetrahydrate
|
|
|
|
|<ref name="weaver17"/>
|-
|KTcO<sub>4</sub>
|potassium pertechnetate
|tetragonal
|a = 5.647, c = 12.91
|411.73
|used to prepare radiopharmaceuticals
|<ref name="weaver17"/>
|-
|RbTcO<sub>4</sub>
|rubidium pertechnetate
|tetragonal
|a = 5.762, c =13.543
|449.65
|
|<ref name="weaver17"/>
|-
|α-CsTcO<sub>4</sub>
|α-caesium pertechnetate
|tetragonal
|a = 5.898, c = 14.38
|
|volatile at temperatures >470K
|<ref name="weaver17"/>
|-
|β-CsTcO<sub>4</sub>
|β-caesium pertechnetate
|orthorhombic
|a = 5.737, b = 5.92, c = 14.341
|486.38
|
|<ref name="weaver17"/>
|-
|TlTcO<sub>4</sub>
|thallium pertechnetate
|orthorhombic
|
|
|
|<ref name="weaver17"/>
|-
|TlTcO<sub>4</sub>
|thallium pertechnetate
|tetragonal
|
|
|
|<ref name="weaver17"/>
|-
|NH<sub>4</sub>TcO<sub>4</sub>
|[[ammonium pertechnetate]]
|tetragonal
|
|
|technetium may be supplied in this form
|<ref name="weaver17"/>
|-
|AgTcO<sub>4</sub>
|silver pertechnetate
|tetragonal
|
|
|
|<ref name="weaver17"/>
|-
|}

== Reactions ==

* Radiolysis of {{chem|Tc|O|4|-}} in nitrate solutions proceeds through the reduction to {{chem|Tc|O|4|2-}} which induces complex disproportionation processes:

: <math chem="">\begin{array}{l}
\ce{{TcO4^-} + {e^-} -> TcO4^2-} \\
\ce{2TcO4^{2-} -> {TcO4^-} + Tc^V} \\
\ce{2Tc^V -> {TcO4^{2-}} + Tc^{IV}} \\
\ce{{Tc^V} + TcO4^{2-} -> {Tc^{IV}} + TcO4-}
\end{array}</math>

* Pertechnetate can be reduced by [[Hydrogen sulfide|H<sub>2</sub>S]] to give Tc<sub>2</sub>S<sub>7</sub>.<ref>{{Cite book|last1=Emeléus|first1=H. J.|url=https://books.google.com/books?id=-SnCsg5jM_kC&pg=PA26|title=Advances in Inorganic Chemistry and Radiochemistry, Volume 11|last2=Sharpe|first2=A. G.|date=1968|publisher=Academic Press|isbn=978-0-08-057860-6|pages=26}}</ref>
* Pertechnetate is also reduced to Tc(IV/V) compounds in alkaline solutions in nuclear waste tanks without adding catalytic metals, reducing agents, or external radiation.  Reactions of mono- and disaccharides with <sup>99m</sup>{{chem|Tc|O|4|-}} yield Tc(IV) compounds that are water-soluble.<ref>{{cite journal|author=D. E. Berning, N. C. Schroeder and R. M. Chamberlin|year=2005|title=The autoreduction of pertechnetate in aqueous, alkaline solutions|url=https://zenodo.org/record/1232814|journal=[[Journal of Radioanalytical and Nuclear Chemistry]]|volume=263|issue=3|pages=613–618|doi=10.1007/s10967-005-0632-x|s2cid=95071892}}</ref>

==Uses==

===Pharmaceutical use===
The half-life of {{simpleNuclide|Tc|99|m}} is long enough that labelling synthesis of the [[radiopharmaceutical]] and scintigraphic measurements can be performed without significant loss of radioactivity.<ref name=schwochau/> The energy emitted from {{simpleNuclide|Tc|99|m}} is 140 keV, which allows for the study of deep body organs. Radiopharmaceuticals have no intended pharmacologic effect and are used in very low concentrations. Radiopharmaceuticals containing {{simpleNuclide|Tc|99|m}} are currently being applied in the determining morphology of organs, testing of organ function, and scintigraphic and emission tomographic imaging. The gamma radiation emitted by the radionuclide allows organs to be imaged ''in vivo'' tomographically. Currently, over 80% of radiopharmaceuticals used clinically are labelled with {{simpleNuclide|Tc|99|m}}. A majority of radiopharmaceuticals labelled with {{simpleNuclide|Tc|99|m}} are synthesized by the reduction of the pertechnetate ion in the presence of ligands chosen to confer organ specificity of the drug. The resulting {{simpleNuclide|Tc|99|m}} compound is then injected into the body and a "gamma camera" is focused on sections or planes in order to image the spatial distribution of the {{simpleNuclide|Tc|99|m}}.

====Specific imaging applications====
{{simpleNuclide|Tc|99|m}} is used primarily in the study of the thyroid gland - its morphology, vascularity, and function. {{chem|Tc|O|4|-}} and [[iodide]], due to their comparable charge/radius ratio, are similarly incorporated into the thyroid gland. The pertechnetate ion is not incorporated into the [[thyroglobulin]]. It is also used in the study of blood perfusion, regional accumulation, and cerebral lesions in the brain, as it accumulates primarily in the [[choroid plexus]].

Pertechnetate salts, such as sodium pertechnetate, cannot pass through the [[blood–brain barrier]]. In addition to the salivary and thyroid glands, {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} localizes in the stomach. {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} is renally eliminated for the first three days after being injected. After a scanning is performed, it is recommended that a patient drink large amounts of water in order to expedite elimination of the radionuclide.<ref>{{cite journal | author = Shukla, S. K., Manni, G. B., and Cipriani, C. | year = 1977 | title = The Behaviour of the Pertechnetate Ion in Humans | journal = [[Journal of Chromatography B]] | volume = 143 | issue = 5 | pages = 522–526 | pmid = 893641 | doi = 10.1016/S0378-4347(00)81799-5}}</ref> Other methods of {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} administration include intraperitoneal, intramuscular, subcutaneous, as well as orally. The behavior of the {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} ion is essentially the same, with small differences due to the difference in rate of absorption, regardless of the method of administration.<ref>{{Cite journal | last1 = Razzak | first1 = M. A. | last2 = Naguib | first2 = M. | last3 = El-Garhy | first3 = M. | year = 1967 | title = Fate of Sodium Pertechnetate-Technetium-99m | journal = Journal of Nuclear Medicine | volume = 8 | issue = 1| pages = 50–59 | pmid = 6019138 }}</ref>

===Synthesis of <sup>99m</sup>TcO<sub>4</sub><sup>−</sup> radiopharmaceuticals===
{{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} is advantageous for the synthesis of a variety of radiopharmaceuticals because Tc can adopt a number of oxidation states.<ref name=schwochau/> The oxidation state and coligands dictate the specificity of the radiopharmaceutical. The starting material {{chem|Na|[|{{simpleNuclide|Tc|99|m}}|O|4|]}}, made available after elution from the generator column, as mentioned above, can be reduced in the presence of complexing ligands. Many different reducing agents can be used, but transition metal reductants are avoided because they compete with {{simpleNuclide|Tc|99|m}} for ligands. [[Oxalate]]s, [[formate]]s, [[hydroxylamine]], and [[hydrazine]] are also avoided because they form complexes with the technetium. Electrochemical reduction is impractical.

Ideally, the synthesis of the desired radiopharmaceutical from {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}}, a reducing agent, and desired ligands should occur in one container after elution, and the reaction must be performed in a solvent that can be injected intravenously, such as a saline solution. Kits are available that contain the reducing agent, usually tin(II) and ligands. These kits are sterile, pyrogen-free, easily purchased, and can be stored for long periods of time. The reaction with {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} takes place directly after elution from the generator column and shortly before its intended use. A high organ specificity is important because the injected activity should accumulate in the organ under investigation, as there should be a high activity ratio of the target organ to nontarget organs. If there is a high activity in organs adjacent to the one under investigation, the image of the target organ can be obscured. Also, high organ specificity allows for the reduction of the injected activity, and thus the exposure to radiation, in the patient. The radiopharmaceutical must be kinetically inert, in that it must not change chemically ''in vivo'' en route to the target organ.

=== As a <sup>99m</sup>Tc carrier ===
A [[technetium-99m generator]] provides the pertechnetate containing the short-lived isotope [[Technetium-99m|<sup>99m</sup>Tc]] for medical uses. This compound is generated directly from [[molybdate]] held on alumina within the generator (see this topic for detail).

==== In nuclear medicine ====
Pertechnetate has a wide variety of uses in diagnostic [[nuclear medicine]]. Since technetate(VII) can substitute for [[iodine]] in the Na/I symporter (NIS) channel in follicular cells of the [[thyroid]] gland, inhibiting uptake of iodine into the follicular cells, <sup>99m</sup>Tc-pertechnetate can be used as an alternative to <sup>123</sup>I in imaging of the thyroid, although it specifically measures uptake and not organification.<ref>{{cite journal
  | last1 = Ryo
  | first1 = U.Y.
  | last2 = Vaidya
  | first2 = P.V.
  | last3 = Schneider
  | first3 = A.B.
  | last4 = Bekerman
  | first4 = C
  | last5 = Pinsky
  | first5 = S.M.
  | title = Thyroid imaging agents: a comparison of I-123 and Tc-99m pertechnetate
  | journal = Radiology
  | volume = 148
  | pages = 819–822
  | year = 1983
  | pmid = 6308711
  | doi = 10.1148/radiology.148.3.6308711
  | issue = 3}}</ref> It has also been used historically to evaluate for [[testicular torsion]], although [[ultrasound]] is more commonly used in current practice, as it does not deliver a radiation dose to the [[testes]]. It is also used in labeling of autologus [[red blood cell]]s for [[Radionuclide angiography|MUGA]] scans to evaluate left ventricular cardiac function, localization of gastrointestinal bleeding prior to embolization or surgical management, and in damaged red blood cells to detect ectopic [[spleen|splenic]] tissue.

It is actively accumulated and secreted by the mucoid cells of the gastric mucosa,<ref>[http://www.uth.tmc.edu/radiology/publish/meckel_diverticulum/index.html Nuclear Imaging of Meckel's Diverticulum: A Pictorial Essay of Pitfalls ] {{webarchive|url=https://web.archive.org/web/20120117032825/http://www.uth.tmc.edu/radiology/publish/meckel_diverticulum/index.html |date=2012-01-17 }} S. Huynh, M.D., R. Amin, M.D., B. Barron, M.D., R. Dhekne, M.D., P. Nikolaidis, M.D., L. Lamki, M.D.. University of Texas Houston Medical School and Memorial Hermann - Texas Medical Center (TMC), St. Luke's Episcopal Hospital and Texas Children Hospital, Houston, Texas. Last Modified September 5, 2007</ref> and therefore, technetate(VII) radiolabeled with technetium-99m is injected into the body when looking for ectopic gastric tissue as is found in a [[Meckel's diverticulum]] with Meckel's scans.<ref>{{cite journal
  | last1 = Diamond
  | first1 = Robert
  | last2 = Rothstein
  | first2 = Robin
  | last3 = Alavi
  | first3 = Abass
  | title = The Role of Cimetidine-Enhanced Technetium 99m-Pertechnetate Imaging for Visualizing Meckel's Diverticulum
  | journal = The Journal of Nuclear Medicine
  | volume = 32
  | issue = 7
  | pages = 1422–1424
  | year = 1991
  | pmid = 1648609
 | url = http://jnm.snmjournals.org/cgi/reprint/32/7/1422.pdf}}</ref>

===Non-radioactive uses===

All technetium salts are mildly radioactive, but some of them have explored use of the element for its chemical properties. In these uses, its radioactivity is incidental, and generally the least radioactive (longest-lived) isotopes of Tc are used. In particular, [[Tc-99|<sup>99</sup>Tc]] (half-life 211,000 years) is used in corrosion research, because it is the decay product of the easily obtained commercial <sup>99m</sup>Tc isotope.<ref name="weaver17"/> Solutions of technetate(VII) react with the surface of [[iron]] to form technetium dioxide, in this way it is able to act as an anodic [[corrosion inhibitor]].<ref>{{cite journal | doi = 10.5006/0010-9312-29.9.361| title = Twenty-Year Inhibition of Corrosion by the Pertechnetate Ion| year = 1973| last1 = Cartledge| first1 = G. H.| journal = Corrosion| volume = 29| issue = 9| pages = 361–362}}</ref>

==See also==
*[[Permanganate]]
*[[Perrhenate]]
*[[Sodium pertechnetate]]

== References ==
{{Reflist}}

{{Thyroid therapy}}
{{Thyroid hormone receptor modulators}}

[[Category:Pertechnetates| ]]
[[Category:Transition metal oxyanions]]
[[Category:Radiopharmaceuticals]]
[[Category:Medical physics]]
[[Category:Corrosion inhibitors]]