Simple Route to [PSH][B9H14] and a Contemporary Study of Its Solid-State Dynamic Behavior

Autor: Bould, Jonathan, Londesborough, Michael G. S., Brus, Jiři, Tok, Oleg, Sanz Miguel, Pablo J., Macías, Ramón
Zdroj: Inorganic Chemistry; September 2023, Vol. 62 Issue: 36 p14568-14579, 12p
Abstrakt: The 1,8-bis(dimethylamino)naphthalenium ([PSH]+) decaborane salt, [PSH][B10H13], has been found to react in ethanol to form [PSH][B9H14] (1), affording a simple route to the synthesis of the arachno-nonaborate anion. This new polyhedral salt is characterized by NMR spectroscopy and X-ray diffraction. The measurement of diffusion coefficients by NMR methods demonstrates that the [PSH]+cation and the [B9H14]−anion form ion pairs in a non-coordinating solvent such as CH2Cl2, whereas in CD3CN the formation of ion pairs was not observed. Insights into the long-known low-energy dynamic behavior, which involves the bridging and endo-terminal hydrogen atoms, are elucidated using DFT calculations. Salts [PSH][B9H14] (1) and [PSH][B9H14]·0.5CHCl3(solvated, 1·0.5CHCl3) have also been studied by X-ray diffraction analysis. A solid-state NMR study has demonstrated that K[B9H14] and [PSH][B9H14] (1) undergo significantly different motion regimes, being a low-energy, weakly temperature-dependent process for 1, which may be ascribed to some type of low-amplitude reorientation of the whole boron cages. This process may be the mechanism for the low- to-room-temperature order–disorder hidden transition found by X-ray analysis.
Databáze: Supplemental Index