Synthesis, XRD Studies and NLO Properties of [p-H(2)NC(6)H(4)CH(2)NH(3)][B(5)O(6)(OH)(4)]·1/2H(2)O and NLO Properties of Some Related Pentaborate(1−) Salts

The non-metal cation pentaborate(1−) salt [p-H(2)NC(6)H(4)CH(2)NH(3)][B(5)O(6)(OH)(4)]·1/2H(2)O (1) was synthesised from B(OH)(3) and p-H(2)NC(6)H(4)CH(2)NH(2) and crystallized from aqueous solution. Compound 1 was characterized by thermal (TGA/DSC), spectroscopic (IR, NMR) and single-crystal X-ray diffraction methods and it was found to crystallize in the non-centrosymmetric point group P2(1). Powder SHG measurements on 1 and some related alkylammonium pentaborate salts, [NH(3)CMe(2)(CH(2)OH)][B(5)O(6)(OH)(4)], [NH(3)CMe(CH(2)OH)(2)][B(5)O(6)(OH)(4)] and [NH(3)CHMeCH(2)OH][B(5)O(6)(OH)(4)], a substituted imidazolium salt, [1,2,3-Me(3)C(3)H(2)N(2)][B(5)O(6)(OH)(4)], a substituted piperidinium salt, [(CH(2))(5)NH(CH(2)CH(2)OH)][B(5)O(6)(OH)(4)], and a substituted pyrrolidinium salt, [S-(+)-2-(HOCH(2))C(4)H(7)NH(2)][B(5)O(6)(OH)(4)], were determined. Compound 1 and all compounds, except [1,2,3-Me(3)C(3)H(2)N(2)][B(5)O(6)(OH)(4)], showed some weak SHG activity with SHG efficiencies of 0.1–0.2 relative to that of KH(2)PO(4) (KDP). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10876-017-1205-1) contains supplementary material, which is available to authorized users.