Between the Sheets: CH ₃ SO ₃ H Molecules Intercalating B ₂ O ₃ Layers

The reaction of boric acid and methanesulfonic acid yielded single crystals of B 6 O 9 ·CH 3 SO 3 H (monoclinic, I 2/ a , Z = 8, a = 873.19(3), b = 14.2254(5), c = 1759.33(8) pm, β = 103.433(2)°, and V = 2125.56(1) × 10 6 pm 3 ). The crystal structure exhibits corrugated layers of the central structural motif, which are planar B 3 O 3 rings, which are linked to each other via oxygen atoms resulting in a trigonal planar coordination of all boron atoms. Intercalated in these layers are chains of methanesulfonic acid molecules showing medium strong hydrogen bonds. The compound has also been analyzed via thermal gravimetry, IR and Raman spectroscopy. 1 H, 11 B, and 13 C solid‐state NMR analyses corroborate the structural findings and are in good agreement with expected values.