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 [ -H NC H CH NH ][B O (OH) ]·1/2H O ( ) was synthesised from B(OH) and -H NC H CH NH and crystallized from aqueous solution. Compound 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 2 . Powder SHG measurements on and some related alkylammonium pentaborate salts, [NH CMe (CH OH)][B O (OH) ], [NH CMe(CH OH) ][B O (OH) ] and [NH CHMeCH OH][B O (OH) ], a substituted imidazolium salt, [1,2,3-Me C H N ][B O (OH) ], a substituted piperidinium salt, [(CH ) NH(CH CH OH)][B O (OH) ], and a substituted pyrrolidinium salt, [ -(+)-2-(HOCH )C H NH ][B O (OH) ], were determined. Compound and all compounds, except [1,2,3-Me C H N ][B O (OH) ], showed some weak SHG activity with SHG efficiencies of 0.1-0.2 relative to that of KH PO (KDP).