Solid-state solvation and anion packing patterns in X-ray structures of crystalline K2(solv)nB12F12 (solv = H2O2(aq), CH3OH, CH3NO2, and CH3CN)

Four new solvates of K2B12F12 have been isolated and structurally characterized, K2(H2O2)2B12F12, K2(CH3OH)2B12F12, K2(CH3NO2)2B12F12, and K2(CH3CN)2B12F12. The packing of [K2(solv)2]2+ cations and B12F122− anions are compared with each other, with the previously published solvates K2(H2O)2B12F12, K2(H2O)4B12F12, and K2(HF)3B12F12, and with the solvent-free salt K2B12F12 to explain why the solid-state solvation of K2B12F12 by some gaseous solvent molecules, including H2O and CH3CN, is both thermodynamically favorable and kinetically facile. The compound K2(H2O2)2B12F12 was found to be energetic and underwent rapid deflagration when scraped with a metal spatula and therefore should only be prepared in small quantities. An alternative procedure for the purification of crude K2B12F12 that does not involve treatment with aqueous H2O2 is described.

Four new solvates of K2B12F12 have been isolated and structurally characterized, K2(H2O2)2B12F12, K2(CH3OH)2B12F12, K2(CH3NO2)2B12F12, and K2(CH3CN)2B12F12. The packing of [K2(solv)2]2+ cations and B12F122− anions are compared with each other, with the previously published solvates K2(H2O)2B12F12, K2(H2O)4B12F12, and K2(HF)3B12F12, and with the solvent-free salt K2B12F12 to explain why the solid-state solvation of K2B12F12 by some gaseous solvent molecules, including H2O and CH3CN, is both thermodynamically favorable and kinetically facile.Figure optionsDownload as PowerPoint slide