A New Chiral Schiff Base with Ferroelectric Property

Abstract

Reaction of 1,1,1,5,5,5-hexafluoropentane-2,4-dione with (1S,2S)-(-)-1,2-diaminocyclohexane afforded a homochiral Schiff base (1Z,4Z)-2,4-bis(trifluoromethyl)-5a, 6,7,8,9,9a-hexahydro-3H-benzo[b][1,4]diazepine (1). Fluorescent analysis showed that it exhibited an intense emission band at 488 nm when the exciting radiation was set at 437 nm. Crystallographic analysis shows that it belongs to chiral space group C 2 with ferroelectric behavior. A typical ferroelectric feature of electric hysteresis loop was obtained, with remanent polarization (Pr) of ca. 0.01 µC/cm 2 and coercive field (Ec) of 0.27 kV/cm.

4-Methoxyanilinium iodide

“…For compounds with dielectric-ferroelectric properties, see: Hang et al (2009) ;Li et al (2008). Table 1 Hydrogen-bond geometry (Å , ).…”

“…Dielectric-ferroelectric constitute an interesting class of materials, comprising organic ligands (Li et al, 2008), metal-organic coordination compounds (Hang et al, 2009) and organic-inorganic hybrids. We were interested in the title compound as a potential candidate for having good dielectric properties.…”

4-(Cyanomethyl)anilinium chloride

“…As a continuation of our study of phase transition materials, including organic ligands (Li et al, 2008), metal-organic coordination compounds (Zhang et al, 2009 ),the dielectric constant of 4-(cyanomethyl)anilinium chloride compound as a function of temperature indicates that the permittivity is basically temperature-independent (dielectric constant equaling to 5.3 to 21.1), suggesting that this compound should be not a real ferroelectrics or there may be no distinct phase transition occurred within the measured temperature range.…”

4-Bromoanilinium hexafluorophosphate monohydrate

“…For background to phase transition materials, see: Li et al (2008); Zhang et al (2009). Experimental Crystal data H atoms treated by a mixture of independent and constrained refinement Á max = 0.48 e Å À3 Á min = À0.54 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). (7) 3.062 (5) 136 (6) O1W-H1WAÁ Á ÁF5 vi 0.62 (7) 2.36 (7) 2.92 (2) 151 (7) Symmetry codes: (i) Àx þ 1; y À 1 2 ; Àz þ 3 2 ; (ii) x; y À 1; z; (iii) Àx þ 1; Ày; Àz þ 2; (iv) Àx þ 1; y þ 1 2 ; Àz þ 3 2 ; (v) Àx þ 1; Ày þ 1; Àz þ 2; (vi) x; y þ 1; z.…”