Sodium pertechnetate: Difference between revisions

| Watchedfields = changed

| verifiedrevid = 446484697

| ImageAlt = Structural formula of sodium pertechnetate

| ImageFile1 = Sodium pertechnetate 3D spacefill.png

| ImageAlt1 = Space-filling models of the component ions of sodium pertechnetate

|Section1={{Chembox Identifiers

| index1_label={{simpleNuclide|Tc|99}}

|

CASNo_Ref = {{cascite|correct|CAS}}

| ChemSpiderID = 64887107

| =

| PubChem = 74086836

| PubChem1 =23689036

| UNII = A0730CX801

| SMILES = [Na+].[O-][Tc](=O)(=O)=O

| SMILES1=[O-][99Tc](=O)(=O)=O.[Na+]

| StdInChI=1S/Na.4O.Tc/q+1;;;;-1;

| StdInChIKey = MKADDTFVKFMZGF-UHFFFAOYSA-N

}}

|Section2={{Chembox Properties

| Formula = NaTcO₄

| MolarMass = 169.89 g/mol

| Appearance = White or pale pink solid

| =

| MeltingPt = < {{convert|1063|K|C F}}<ref name="german2017"/>

| BoilingPt =

| Solubility = Soluble

}}

|Section3={{Chembox Hazards

| =

| =

| AutoignitionPt =

}}

|Section4={{Chembox Structure

|Structure_ref = <ref name="german2017">{{cite journal |last1=German |first1=Konstantin E. |last2=Grigoriev |first2=Mikhail S. |last3=Garashchenko |first3=Bogdan L. |last4=Kopytin |first4=Alexander V. |last5=Tyupina |first5=Ekaterina A. |title=Redetermination of the crystal structure of {{chem|Na|Tc|O|4}} at 100 and 296 K based on single-crystal X-ray data |journal=Acta Crystallographica Section E |date=1 July 2017 |volume=73 |issue=7 |pages=1037–1040 |doi=10.1107/S2056989017008362|pmid=28775877 |pmc=5499285 |s2cid=31507873 }}</ref>

|CrystalStruct = [[Scheelite]]

|SpaceGroup = I4₁/a

| LattConst_a = {{val|5.3325|(1)||ul=Å}}

| LattConst_c = {{val|11.8503|(3)|u=Å}}

| UnitCellFormulas = 4

|Section8={{Chembox Related

| OtherAnions = [[Sodium permanganate]]; [[sodium perrhenate]]

| OtherCations = [[Ammonium pertechnetate]]

| OtherFunction =

| OtherFunction_label =

| OtherCompounds = [[Technetium heptoxide]]}}

}}

'''Sodium pertechnetate''' is the [[inorganic compound]] with the formula NaTcO₄. This colourless salt contains the [[pertechnetate]] anion, {{chem|Tc|O|4|-}} that has slightly distorted tetrahedron symmetry both at 296 K and at 100 K<ref>{{cite journal |last1=German |first1=K. E. |last2=Grigoriev |first2=M. S. |last3=Garashchenko |first3=B. L. |last4=Kopytin |first4=A. V. |last5=Tyupina |first5=E. A. |date=2017-07-01 |title=Redetermination of the crystal structure of NaTcO4 at 100 and 296 K based on single-crystal X-ray data |url=https://scripts.iucr.org/cgi-bin/paper?wm5391 |journal=Acta Crystallographica Section E: Crystallographic Communications |language=en |volume=73 |issue=7 |pages=1037–1040 |doi=10.1107/S2056989017008362 |issn=2056-9890 |pmc=5499285 |pmid=28775877}}</ref> while the coordination polyhedron of the [https://journals.iucr.org/e/issues/2017/07/00/wm5391/wm5391fig3.html sodium cation] is different from typical for [[scheelite]] structure. The radioactive {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} anion is an important [[radiopharmaceutical]] for [[medical diagnosis|diagnostic]] use. The advantages to {{simpleNuclide|Tc|99|m}} include its short [[half-life]] of 6 hours and the low radiation exposure to the patient, which allow a patient to be injected with activities of more than 30 millicuries.<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> {{chem|Na|[|{{simpleNuclide|Tc|99|m}}O|4|]}} is a precursor to a variety of derivatives that are used to image different parts of the body.

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> 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 4/2 is only +0.738 V in acidic solution, as compared to +1.695 V for 4/2.<ref name=schwochau/> Because of its diminished oxidizing power, 4 is stable in alkaline solution. 4 is more similar to 4. Depending the reducing agent, 4 can be converted to derivatives containing Tc(VI), Tc(V), and Tc(IV).<ref>'' Britannica: Technetium''</ref> In the absence of strong complexing ligands, 4 is reduced to a +4 oxidation state via the formation of 2 hydrate.<ref name=schwochau />

The half-life of Tc 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 Tc 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 Tc 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 Tc. A majority of radiopharmaceuticals labelled with Tc are synthesized by the reduction of the pertechnetate ion in the presence of ligands chosen to confer organ specificity of the drug. The resulting Tc compound is then injected into the body and a "gamma camera" is focused on sections or planes in order to image the distribution of the Tc.

Tc is used primarily in the study of the thyroid gland - its morphology, vascularity, and function. 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]].

Sodium pertechnetate cannot pass through the [[ barrier]]. In addition to the salivary and thyroid glands, 4 localizes in the stomach. 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]] | volume = 143 | issue = 5 | pages = 522–526 | pmid = 893641 | doi = 10.1016/S0378-4347(00)81799-5}}</ref> Other methods of 4 administration include intraperitoneal, intramuscular, subcutaneous, as well as orally. The behavior of the 4 ion is essentially the same, with small differences due to the difference in rate of absorption, regardless of the method of administration.<ref>{{ 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>

*Radiolysis of 4 in nitrate solutions proceeds through the reduction to 42 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 react with {{chem|link=Hydrogen sulfide|H|2|S}} to give {{chem|Tc|2|S|7}}.<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 can also be 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 {{chem|{{simpleNuclide|Tc|99|m}}|O|4|-}} yield Tc(IV) compounds that are water-soluble.<ref>{{cite journal | author = D. E. Berning, N. C. Schroeder and R. M. Chamberlin | title = The autoreduction of pertechnetate in aqueous, alkaline solutions | year = 2005 | journal = [[Journal of Radioanalytical and Nuclear Chemistry]] | volume = 263 | issue = 3| pages = 613–618 | doi = 10.1007/s10967-005-0632-x| s2cid = 95071892 | url = https://zenodo.org/record/1232814 }}</ref>

<!-- Dead note "7": Lukens, W. W., Bucher, J. J., Edelstein, N. M., and Shuh, D. K. (2001) Radiolysis of 4- in Alkaline, Nitrate Solutions: Reduction by NO₃. ''J. Phys. Chem. A,'' ''105'', 9611-9615. -->

{{Technetium compounds}}

{{Thyroid hormone receptor modulators}}

[[Category:Peripherally selective drugs]]

[[Category:Technetium-99m]]