Sequential transformations in assemblies based on octamolybdate clusters and 1,2-bis(4-pyridyl)ethane

Abstract:

The new hybrid inorganic-organic solids [Mo<inf>8</inf>O <inf>26</inf>][H<inf>2</inf>bpe]<inf>2</inf> (1), {[Mo<inf>8</inf>O <inf>26</inf>(μ-bpe)][H<inf>2</inf>bpe]<inf>2</inf>}<inf>n</inf> (2), [Mo<inf>8</inf>O<inf>26</inf>(Hbpe)<inf>2</inf>][H<inf>2</inf>bpe] (3), and {[Mo<inf>8</inf>O<inf>26</inf>][H<inf>2</inf>bpe]<inf>2</inf>}<inf>n</inf> (4) were synthesized under hydrothermal conditions. The crystal structure of 1 contains the discrete octamolybdate β-isomer, whereas in 3 the inorganic building unit is a functionalized octamolybdate of general formula [Mo <inf>8</inf>O<inf>26</inf>X<inf>2</inf>]⁽²ⁿ⁺⁴⁾. A similar building unit is found in 2 and 4, but forming part of polymeric 1D-arrays. In 2 the polymer is constructed from [Mo<inf>8</inf>O<inf>26</inf>(μ-bpe)] ^4-, and the functionalization of the anionic cluster in 4 occurs through Mo-O-Mo bonds. The sequential hydrothermal 2/3 → 1 and 1 → 4 transformations were observed at 145 and 180°C, respectively. However, thermal studies of 1 and 4 revealed that both materials do not suffer any phase transitions below 340°C for 1 or <350°C for 4, indicating that such transformations are possible only under the hydrothermal conditions. An XRPD study as a function of the temperature of 1 also demonstrated the negligible structural changes before 330°C. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

Año de publicación:

2007

Keywords:

Fuente:

scopus