Polyborate Anions Partnered with Large Nonmetal Cations: Triborate(1-), Pentaborate(1-) and Heptaborate(2-) Salts

New polyborate salts containing bulky nonmetal cations have been prepared from either the free organic base or the [nonmetal cation][OH] in an aqueous solution with methanol: 1-adamantylammonium pentaborate [C10H18N][B5O6(OH)(4)] (1), 2-adamantylammonium pentaborate dihydrate [C10H18N][B5O6(OH)(4)]2H(2)O (2), N,N-dimethyl-1-adamantylammonium pentaborate boric acid monohydrate [C12H22N][B5O6(OH)(4)]B(OH)(3)H2O (3), N,N,N-trimethyl-1-adamantylammonium pentaborate trihydrate [C13H24N][B5O6(OH)(4)]3H(2)O (4), N,N,N-trimethyl-2-adamantylammonium pentaborate trihydrate [C13H24N][B5O6(OH)(4)]3H(2)O (5), dibenzylammonium pentaborate sesquihydrate [C14H16N][B5O6(OH)(4)]1.5H(2)O (6), bis(triphenylphosphine)iminium pentaborate sesquihydrate [C36H30NP2][B5O6(OH)(4)]1.5H(2)O (7), bis(triphenylphosphine)iminium triborate2.5hydrate [C36H30NP2][B3O3(OH)(4)]2.5H(2)O (8), 4,4'-bipiperidinium heptaborate dihydrate [C10H22N2][B7O9(OH)(5)]2H(2)O (9). All compounds were characterized by thermal (TGA/DSC) and spectroscopic (NMR, IR) analysis. Compounds 3-5 and 9 were characterized by single-crystal XRD studies. The waters of crystallization in 3-6 and the boric acid of crystallization in 3 play important structural roles in expanding the supramolecular pentaborate(1-) lattices to accommodate the bulkier cations.