Studies of New Antiferroelectric Liquid Crystal Based on Quantum-Chemical Model

Abstract

Physical properties of new thermotropic antiferroelectric liquid crystal have been studied. Experiments were done by use of complementary methods such as differential scanning calorimetry, polarizing optical microscopy and X-ray powder diffractometry. Acquired data from X-ray powder diffractometry was examined under application of quantum chemical approach. It has been found that compound studied exhibits stable enantiotropic antiferroelectric SmC∗A phase in the wide temperature range while ferroelectric phase SmC∗ is very narrow.

Full text

a,∗a b c c a
b
a
b
c
∗
A
∗
∗
A
∗
∗ ∗
A
∗
∗
∗
A
6 13 6 13
µ
◦
◦

µ
◦
◦ ◦
3
10−6
k
k
∗
A
∗

◦ ◦
◦
∗
A
5◦
15◦25◦
k
k
◦
TONSET
◦
∆H∆S k
◦
TONSET
◦
∆H∆S
−8.1−16.37
−6.3−15.15
−17.6−42.68
−7.8−16.04
−6.1−14.87
−18.1−44.03
−8.3−16.89
−6.5−15.56
−18.3−44.68
−8.5−17.37
−6.7−15.87
−18.0−44.16
−8.4−17.14
−6.6−15.72
−17.8−43.67
−8.5−17.15
−6.6−15.75
−17.9−44.00
−8.5−18.38
−6.7−16.15
−17.4−42.60
Cr 80.3◦
−→ SmC∗
A
134.0◦
−→ SmC∗138.3◦
−→ Is Is 143.3◦
−→ SmC∗137.8◦
−→ SmC∗
A
72.7◦
−→ Cr
2θ
1◦5◦

a b c α ◦β◦γ◦
P m 2 (2||Y
∗ ∗
A
∗
A