AUTHOR=Duan Yan , Clemente-Juan Juan M. , Giménez-Saiz Carlos , Coronado Eugenio 

TITLE=Large Magnetic Polyoxometalates Containing the Cobalt Cubane ‘[CoIIICo3II(OH)3(H2O)6–m(PW9O34)]3−' (m = 3 or 5) as a Subunit

JOURNAL=Frontiers in Chemistry

VOLUME=6

YEAR=2018

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2018.00231

DOI=10.3389/fchem.2018.00231

ISSN=2296-2646

ABSTRACT=<p>A synthetic procedure is presented to construct new magnetic polyoxometalates (POMs) containing one or two subunits of ‘[Co<sup>III</sup>Co<inline-formula><mml:math id="M2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mrow></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow><mml:mrow><mml:mtext>II</mml:mtext></mml:mrow></mml:msubsup></mml:math></inline-formula>(OH)<sub>3</sub>(H<sub>2</sub>O)<sub>6−m</sub>(PW<sub>9</sub>O<sub>34</sub>)]<sup>3−</sup>' (<italic>m</italic> = 3 or 5). The substitution of the water ligands present in these subunits by oxo or hydroxo ligands belonging to other POM fragments, gives rise to four, larger POM anions: [Co<sub>7</sub>(OH)<sub>6</sub>(H<sub>2</sub>O)<sub>6</sub>(PW<sub>9</sub>O<sub>34</sub>)<sub>2</sub>]<sup>9−</sup> (<bold>2</bold>), [Co<sub>7</sub>(OH)<sub>6</sub>(H<sub>2</sub>O)<sub>4</sub>(PW<sub>9</sub>O<sub>34</sub>)<sub>2</sub>]<inline-formula><mml:math id="M3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mrow></mml:mrow><mml:mrow><mml:mtext>n</mml:mtext></mml:mrow><mml:mrow><mml:mn>9</mml:mn><mml:mtext>n</mml:mtext><mml:mo>-</mml:mo></mml:mrow></mml:msubsup></mml:math></inline-formula> (<bold>2</bold>′), [Co<sub>11</sub>(OH)<sub>5</sub>(H<sub>2</sub>O)<sub>5</sub>(W<sub>6</sub>O<sub>24</sub>)(PW<sub>9</sub>O<sub>34</sub>)<sub>3</sub>]<sup>22−</sup> (<bold>3</bold>) and [{Co<sub>4</sub>(OH)<sub>3</sub>(H<sub>2</sub>O)(PW<sub>9</sub>O<sub>34</sub>)}<sub>2</sub>{K⊂(H<sub>2</sub>W<sub>12</sub>O<sub>41</sub>)<sub>2</sub>}{Co(H<sub>2</sub>O)<sub>4</sub>}<sub>2</sub>]<sup>17−</sup> (<bold>4</bold>). The crystal structures, magnetic characterization and stabilities in aqueous solutions of these POM derivatives are also presented.</p>