New hybrid: [H-β-(4-pyridyl)-Ala-OH] tetrafluoroborate – crystal structure and strong piezoelectricity

Abstract

A new amino acid based crystal [H-β-(4-pyridyl)-Ala-OH][BF₄] was synthesized. The structure was determined using single-crystal diffraction. The title salt crystallizes in the polar, piezoelectric P2₁ space group. It was demonstrated by means of piezoelectric force microscopy that the piezoresponse of the [H-β-(4-pyridyl)-Ala-OH][BF₄] crystal is higher than that of lithium niobate, LiNbO₃. The crystal structure, specifically the hydrogen bond network, and the physical properties of the alanine derivative were correlated. The thermal behavior of the title crystal was studied by means of thermogravimetric analysis (TGA). The high piezoresponse of [H-β-(4-pyridyl)-Ala-OH][BF₄] and other alanine salts was discussed.