Electronic supplementary material

Investigations on Photo and Electrically Switchable Asymmetric Bent-core Liquid Crystals

Murugesan Vijay Srinivasana, Palaninathan Kannana∗, Arun Royb

a. Department of Chemistry, Anna University, Chennai-600 025, India

b. Soft Condensed Matter, Raman Research Institute, Bangalore-560 080, India

2.3. Synthesis of 4-((4'-hydroxyphenylazo)phenyl)acetamide (1)

The synthesis of compound 4-((4'-hydroxyphenylazo)phenyl)acetamide was prepared

according to our previous report [15]. 4-Aminophenylacetamide (10.4g, 0.07 mol) was cooled in

ice bath, then a mixture of hydrochloric acid (16 mL) and water (16 mL) added to the reaction

mixture with constant stirring and the resultant mixture diazotized by slow addition of sodium

nitrite (4.8g, 0.07 mol) in 20 mL of water, at temperature below 5 ºC. Phenol (7.4g, 0.07 mol)

was dissolved in 10 % sodium hydroxide solution (45 mL) in round bottom flask and cooled to 5

ºC. The above reaction mixture stirred vigorously then the diazonium chloride solution was

added drop wise to the reaction mixture and kept in an ice bath for 30 min. After completion of

the reaction, the mixture was poured into water (500 mL) and acidified with aqueous

hydrochloric acid to obtain orange colored product. The crude product is filtered and washed

well with water and resultant dried in vacuum oven at 60 ºC for 2 days (Yield: 68 %).

1:C14H13N3O2: Calcd. C, 65.17; H, 5.13; N, 16.46; O, 12.54; found C, 65.03; H, 5.22; N,

16.36; O, 13.39; FT-IR; 3308, 3040, 1601, 1585, 1429; 1H NMR (CDCl3, 400 MHz), δ (ppm):

8.1 (d, 1H, -NH-COCH3), 7.90 (d, J=8 Hz, 2H, Ar-H), 7.81 (d, J=8 Hz, 2H, Ar-H), 7.69 (d, J=8

Hz, 2H, Ar-H), 6.81 (d, J=8 Hz, 2H, Ar-H), 5.15 (s, H, -OH), 1.81 (s, 3H, -CH 3). 13C NMR

(CDCl3, 400 MHz), δ (ppm): 168.1, 160.9, 148.1, 144.9, 140.1, 124.2, 122.7, 121.1, 116.2, 22.0

and 14.6.

2.4. Synthesis of 4-((4'-hexyloxyphenylazo)phenyl)acetamide (2a)

The synthesis of compound 4-((4'-hexyloxyphenylazo)phenyl)acetamide (2a) was

prepared according to our previous report [15]. The synthesis of 4-(4'-

hexyloxyphenylazo)phenyl)acetamide carried by suspension of

(4-(4'-hydroxyphenylazo)phenyl)acetamide (2.5g, 0.01 mol), anhydrous K2CO3 (2.76g, 0.02

mol), 0.5 wt % of KI (0.35g) in dry acetone (80 mL) and the reaction was carried out for 24 h at

90 ºC with constant stirring. The drop wise addition of 1-bromohexane (1.65g, 0.01mol) to the

reaction mixture and refluxed for 24 h. After completion of the reaction, the mixture was filtered

and washed with excess of DMF. The filtrate was poured in to ice water and extracted using

diethyl ether, dried with anhydrous sodium sulphate. An orange colored solid was obtained after

the solvent evaporated under vacuum, then product purified by column chromatography (silica

gel, chloroform) (Yield: 2.54g, 75 %). A similar procedure was adopted for preparation of other

even numbered alkyl series such as octyl, decyl and dodecyl (2b-2d) derivatives.

2a: C20H25N3O2; Calcd. C, 70.77; H, 7.42; N, 12.38; O, 9.43; found C,70.62; H, 7.31; N,

12.48; O, 9.59. FT-IR; 3318, 3055, 2852, 1667, 1585, 1418,1258,1151.1H-NMR (CDCl3, 400

MHz), δ (ppm): 8.01 (d, 1H, -NH), 7.85 (d, J=8Hz, 2H, Ar-H), 7.80-74 (d, J=8Hz, 4H, Ar-H),

6.85 (d, J=8Hz, 2H, -Ar-H), 3.90 (m, 2H, -OCH2-), 1.93 (s, 3H, CH3-CO-), 1.73 (m, 2H, -CH2-),

1.30-1.29 (m, 6H, -CH2-), 0.9 (t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz),168.1, 158.6, 148.5,

144.2, 140.3, 123.5, 123,1, 121.0, 114.7, 68, 31, 29.5, 22.8, 22.1 and 14.0.

2.4. Synthesis of 4-((4'-octyloxyphenylazo)phenyl)acetamide (2b)

The synthesis of 4-(4'-octyloxyphenylazo)phenyl)acetamide carried by suspension of

(4-(4'-hydroxyphenylazo)phenyl)acetamide (2.5g, 0.01 mol), anhydrous K2CO3 (2.76g, 0.02

mol), 0.5 wt % of KI (0.35g) in dry acetone (80 mL) and the reaction was carried out for 24 h at

90 ºC with constant stirring. The drop wise addition of 1-bromoctane (1.93g, 0.01mol) to the

reaction mixture and refluxed for 24 h. After completion of the reaction, the mixture was filtered

and washed with excess of DMF. The filtrate was poured in to ice water and extracted using

diethyl ether, dried with anhydrous sodium sulphate. An orange colored solid was obtained after

the solvent evaporated under vacuum, then product purified by column chromatography (silica

gel, chloroform) (Yield: 2.71g, 74 %).

2b: C22H29N3O2; Calcd. C, 71.9; H, 7.95; N, 11.43; O, 8.71; found C,70.52; H, 7.35; N,

12.42; O, 9.71. FT-IR; 3317, 3052, 2852, 1664, 1579, 1414,1258,1153.1H-NMR (CDCl3, 400

MHz), δ (ppm): 8.12 (d, 1H, -NH), 7.83 (d, J=8Hz, 2H, Ar-H), 7.81-7.74 (d, J=8Hz, 4H, Ar-H),

6.86 (d, J=8Hz, 2H, -Ar-H), 3.91 (m, 2H, -OCH2-), 1.93 (s, 3H, CH3-CO-), 1.77 (m, 2H, -CH2-),

1.35-29 (m, 10H, -CH2-), 0.89 (t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz), 168.5, 165.4, 160.6,

148.3, 144.2, 141.3, 123.3, 123,1, 121.3, 114.4, 68.4, 32.1, 28.1, 22.6, 22.3 and 14.1.

2.4. Synthesis of 4-((4'-decyloxyphenylazo)phenyl)acetamide (2c)

The synthesis of 4-(4'-decyloxyphenylazo)phenyl)acetamide carried by suspension of

(4-(4'-hydroxyphenylazo)phenyl)acetamide (2.5g, 0.01 mol), anhydrous K2CO3 (2.76g, 0.02

mol), 0.5 wt % of KI (0.37g) in dry acetone (80 mL) and the reaction was carried out for 24 h at

90 ºC with constant stirring. The drop wise addition of 1-bromodecane (2.2g, 0.01mol) to the

reaction mixture and refluxed for 24 h. After completion of the reaction, the mixture was filtered

and washed with excess of DMF. The filtrate was poured in to ice water and extracted using

diethyl ether, dried with anhydrous sodium sulphate. An orange colored solid was obtained after

the solvent evaporated under vacuum, then product purified by column chromatography (silica

gel, chloroform) (Yield: 2.84g, 72 %).

2c: C24H33N3O2; Calcd. C, 72.88; H, 8.41; N, 10.62; O, 8.09; found C,72.82; H, 8.51; N,

10.57; O, 8.10. FT-IR; 3317, 3053, 2851, 1667, 1585, 1415,1253,1151.1H-NMR (CDCl3, 400

MHz), δ (ppm): 8.05 (d, 1H, -NH), 7.81 (d, J=8Hz, 2H, Ar-H), 7.80-7.74 (d, J=8Hz, 4H, -Ar-H),

6.81 (d, J=8Hz, 2H, -Ar-H), 3.91 (m, 2H, -OCH2-), 1.93 (s, 3H, CH3-CO-), 1.75 (m, 2H, -CH2-),

1.31-1.27 (m, 14H, -CH2-), 0.9 (t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz), 168.1, 165.3, 159.9,

148.3, 144.1, 140.5, 123.7, 123,4, 121.5, 114.4, 68.7, 30.5, 29.8, 22.6, 22.3 and 14.0.

2.4. Synthesis of 4-((4'-dodecyloxyphenylazo)phenyl)acetamide (2d)

The synthesis of 4-(4'-dodecyloxyphenylazo)phenyl)acetamide carried by suspension of

(4-(4'-hydroxyphenylazo)phenyl)acetamide (2.5g, 0.01 mol), anhydrous K2CO3 (2.76g, 0.02

mol), 0.5 wt % of KI (0.38g) in dry acetone (80 mL) and the reaction was carried out for 24 h at

90 ºC with constant stirring. The drop wise addition of 1-bromododecane (2.49 g, 0.01mol) to the

reaction mixture and refluxed for 24 h. After completion of the reaction, the mixture was filtered

and washed with excess of DMF. The filtrate was poured in to ice water and extracted using

diethyl ether, dried with anhydrous sodium sulphate. An orange colored solid was obtained after

the solvent evaporated under vacuum, then product purified by column chromatography (silica

gel, chloroform) (Yield: 2.99g, 92 %).

2d: C26H37N3O2; Calcd. C, 73.72; H, 8.80; N, 9.92; O, 7.55; found C,73.62; H, 8.81; N,

9.48; O, 8.09. FT-IR; 3320, 3053, 2985, 2851, 1665, 1575, 1415,1255,1151.1H-NMR (CDCl3,

400 MHz), δ (ppm): 8.07 (d, 1H, -NH), 7.81 (d, J=8Hz, 2H, Ar-H), 7.82-7.71 (d, J=8Hz, 4H, Ar-

H), 6.81 (d, J=8Hz, 2H, Ar-H), 3.91 (m, 2H, -OCH2-), 1.93 (s, 3H, CH3-CO-), 1.77 (m, 2H, -

CH2-), 1.33-1.26 (m, 18H, -CH2-), 0.89 (t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz), 168.5, 165.2,

159.8, 148.1, 144.1, 140.1, 125.1, 123.2, 121.7, 113.9, 67.5, 32.4, 29.5, 22.4, 22.3 and 14.1.

2.5. Synthesis of 4-(4'-hexyloxyphenylazo) aniline (3a)

Synthesis of 4-(4'-hexyloxyphenylazo) aniline (3a) was prepared according to our

previous report [15]. The hydrolysis of 4-((4'-hexyloxyphenylazo)phenyl)acetamide (3.38g, 0.01

mol) carried out in ethanol (100 mL) and conc. HCl (3 mL, 0.03 mol) then the reaction mixture

was refluxed for 4 h. After completion of the reaction, the mixture poured into water (500 mL)

and neutralized with saturated NaHCO3 solution and extracted using chloroform, dried with

sodium sulphate. The crude product was recrystallized from ethanol to obtained dark brown

color 4-(4'-hexyloxyphenylazo) aniline (Yield: 2.82g, 95 %). A similar procedure was adopted

for preparation of other even numbered alkyl series such as octyl, decyl and dodecyl (3b-3d)

derivatives.

3a: C18H23N3O; Calcd. C, 72.70; H, 7.8; N, 14.13; O, 5.38 found C, 72.68; H, 7.81; N,

14.11; O, 5.40. FT-IR; 3465, 3421, 3057, 2856, 1590, 1474,1253, 1145. 1H-NMR (CDCl3, 400

MHz), δ (ppm): 7.77 (d, J=8Hz, 2H, Ar-H), 7.60 (d, J=8Hz, 2H, Ar-H), 6.85-6.66 (d, J=8Hz, 4H,

Ar-H), 3.96 (m, 2H, Ar-NH2), 3.70 (m, 2H, -OCH2-), 1.73 (d, 2H, -CH2-),1.31-1.26 (m, 6H, -

CH2-), 0.8 (t, 3H, -CH3). 13C-NMR (CDCl3, 400 MHz), 158.4, 150.4, 144.2, 142.9, 141.8, 122.5,

116.1, 114.0, 67.5, 27.2, 25.3, 22.2 and 14.0.

2.5. Synthesis of 4-(4'-octyloxyphenylazo) aniline (3b)

The hydrolysis of 4-((4'-octyloxyphenylazo)phenyl)acetamide (3.67g, 0.01 mol) carried

out in ethanol (100 mL) and conc. HCl (3 mL, 0.03 mol) then the reaction mixture was refluxed

for 4 h. After completion of the reaction, the mixture poured into water (500 mL) and neutralized

with saturated NaHCO3 solution and extracted using chloroform, dried with sodium sulphate.

The crude product was recrystallized from ethanol to obtained dark brown color 4-(4'-

octyloxyphenylazo)aniline (Yield: 2.9g, 92 %).

3b: C20H27N3O; Calcd. C, 73.81; H, 8.36; N, 12.91; O, 4.92; found C, 73.68; H, 8.81; N,

12.51; O, 4.80. FT-IR; 3462, 3057, 2986, 2856, 1592, 1464, 1252, 1141. 1H-NMR (CDCl3, 400

MHz), δ (ppm): 7.78 (d, J=8Hz, 2H, Ar-H), 7.61 (d, J=8Hz, 2H, Ar-H), 6.84-6.66 (d, J=8Hz, 4H,

Ar-H), 3.95 (m, 2H, Ar-NH2), 3.79 (m, 2H, -OCH2-), 1.77 (d, 2H, -CH2-),1.31-1.28 (m, 10H, -

CH2-), 0.89 (t, 3H, -CH3). 13C-NMR (CDCl3, 400 MHz), 159.4, 150.1, 144.5, 142.3, 141.1, 122.1,

116.5, 114.2, 67.4, 28.2, 25.4, 22.2 and 13.8.

2.5. Synthesis of 4-(4'-decyloxyphenylazo) aniline (3c)

The hydrolysis of 4-((4'-decyloxyphenylazo)phenyl)acetamide (3.95g, 0.01 mol) carried

out in ethanol (100 mL) and conc. HCl (3 mL, 0.03 mol) then the reaction mixture was refluxed

for 4 h. After completion of the reaction, the mixture poured into water (500 mL) and neutralized

with saturated NaHCO3 solution and extracted using chloroform, dried with sodium sulphate.

The crude product was recrystallized from ethanol to obtained dark brown color 4-(4'-

decyloxyphenylazo) aniline (Yield: 3.3g, 96 %).

3c: C22H31N3O; Calcd. C, 74.75; H, 8.84; N, 11.89; O, 4.53 found C, 74.68; H, 8.81; N,

11.85; O, 4.66. FT-IR; 3461, 3425, 3055, 2983, 2851, 1595, 1473,1253, 1143. 1H-NMR (CDCl3,

400 MHz), δ (ppm): 7.80 (d, J=8Hz, 2H, Ar-H), 7.63 (d, J=8Hz, 2H, Ar-H), 6.85-6.69 (d, J=8Hz,

4H, Ar-H), 3.97 (m, 2H, Ar-NH2), 3.70 (m, 2H, -OCH2-), 1.81 (d, 2H, -CH2-),1.31-1.25 (m, 14H,

-CH2-), 0.88 (t, 3H, -CH3). 13C-NMR (CDCl3, 400 MHz): 159.7, 150.1, 144.1, 142.3, 141.5,

122.3, 115.7, 114.9, 67.4, 27.3, 24.3, 23.1 and 14.1.

2.5. Synthesis of 4-(4'-dodecyloxyphenylazo) aniline (3d)

The hydrolysis of 4-((4'-dodecyloxyphenylazo)phenyl)acetamide (4.23g, 0.01 mol)

carried out in ethanol (100 mL) and conc. HCl (3 mL, 0.03 mol) then the reaction mixture was

refluxed for 4 h. After completion of the reaction, the mixture poured into water (500 mL) and

neutralized with saturated NaHCO3 solution and extracted using chloroform, dried with sodium

sulphate. The crude product was recrystallized from ethanol to obtained dark brown color 4-(4'-

dodecyloxyphenylazo) aniline (Yield: 3.61g, 95 %).

3d: C18H23N3O; Calcd. C, 75.55; H, 9.25; N, 11.01; O, 4.19 found C, 75.69; H, 9.21; N,

11.11; O, 3.99. FT-IR; 3461, 3057, 2984, 2856, 1592, 1414,1253, 1141. 1H-NMR (CDCl3, 400

MHz), δ (ppm): 7.79 (d, J=8Hz, 2H, Ar-H), 7.69 (d, J=8Hz, 2H, Ar-H), 6.85-6.67 (d, J=8Hz, 4H,

Ar-H), 3.99 (m, 2H, Ar-NH2), 3.65 (m, 2H, -OCH2-), 1.81 (d, 2H, -CH2-), 1.31-1.29 (m, 18H, -

CH2-), 0.89 (t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz), 159.1, 151.3, 144.1, 142.1, 141.1, 122.1,

116.1, 114.0, 68.1, 29.2, 25.3, 22.1 and 14.1.

2.5. Synthesis of 4-((3-formylphenoxy)carbonyl)phenyl4-hexyloxybenzoate (7a)

The 4-((3-formylphenoxy)carbonyl)phenyl4-hexyloxybenzoate was synthesized by

esterification reaction of 4-(4'-hexyloxybenzoyloxy)benzoic acid (3.42g, 0.01 mol),

DCC (2.47g, 0.012 mol) with 3-hydroxybenzaldehyde (1.22g, 0.01mol), 5 wt % of DMAP

(0.046g) in dry dichloromethane (50 ml) and reaction mixture was stirred for 12 h. After

completion of reaction, the precipitated N, N′-9-dicyclohexylurea was filtered, washed with

excess of dichloromethane and filtrate concentrated in a rotary evaporator. The residue was

purified by silica gel column using chloroform as eluent. (Yield: 3.7g, 85%) A similar procedure

was adopted for preparation of other even numbered alkyl series such as octyl, decyl and dodecyl

(7b-7d) derivatives.

7a : C27H26O6: Calcd C, 72.63; H, 5.87; O, 21.50; found C, 72.61; H, 5.81; O, 21.58. FT-

IR (KBr pellet, cm-1): 2916, 2851, 1736, 1603, 1262. 1H NMR (CDCl3, 400 MHz) δ (ppm): 9.77

(s, 1H, -CHO), 8.20-8.06 (d, J=8Hz, 4H, Ar-H), 7.73 (d, J=8Hz, 1H, Ar-H), 7.52 (s, 1H, Ar-H),

7.50 (t, J=8Hz, 1H, Ar-H), 7.43 (d, J=8Hz, 1H, Ar-H), 7.30 (d, J=8Hz, 2H, Ar-H), 6.9 (d,

J=8.4Hz, 2H, Ar-H), 3.79 (t, 2H, -OCH2), 1.79 (m, 2H, -CH2-), 1.33-1.29 (m, 6H, -CH2-), 0.91(t,

3H, -CH3). 13C NMR (CDCl3, 400 MHz) δ (ppm): 191.0, 165.2, 162.7, 156.5, 151.9, 137.2,

130.7, 130.2, 127.6, 122.4, 114.6, 68.4, 31.9, 29.8, 22.5 and 14.4.

2.5. Synthesis of 4-((3-formylphenoxy)carbonyl)phenyl 4-octyloxybenzoate (7b)

The 4-((3-formylphenoxy)carbonyl)phenyl 4-octyloxybenzoate was synthesized by

esterification reaction of 4-(4'-octyloxybenzoyloxy)benzoic acid (3.7g, 0.01 mol),

DCC (2.47g, 0.012 mol) with 3-hydroxybenzaldehyde (1.22g, 0.01mol), 5 wt % of DMAP

(0.047g) in dry dichloromethane (50 ml) and reaction mixture was stirred for 12 h. After

completion of reaction, the precipitated N, N′-9-dicyclohexylurea was filtered, washed with

excess of dichloromethane and filtrate concentrated in a rotary evaporator. The residue was

purified by silica gel column using chloroform as eluent. (Yield: 3.7g, 80%).

7b : C29H30O6: Calcd C, 73.40; H, 6.37; 20.23; found C, 73.31; H, 6.31; O, 20.38. FT-IR

(KBr pellet, cm-1): 2917, 2855, 1734, 1603, 1411, 1262. 1H NMR (CDCl3, 400 MHz) δ (ppm):

9.78 (s, 1H, -CHO), 8.18-8.06 (d, J=8Hz, 4H, Ar-H), 7.75 (d, J=8Hz, 1H, Ar-H), 7.51 (s, 1H,

Ar-H), 7.48 (t, J=8Hz, 1H, Ar-H), 7.41 (d, J=8Hz, 1H, Ar-H), 7.33 (d, J=8Hz, 2H, Ar-H), 6.91

(d, J=8.4Hz, 2H, Ar-H), 3.78 (t, 2H, -OCH2), 1.88 (m, 2H, -CH2-), 1.33-1.29 (m, 10H, -CH2-),

0.89 (t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz) δ (ppm): 191.3, 164.5, 162.3, 156.4, 151.5,

145.4, 136.1, 131.4, 130.2, 127.6, 122.4, 114.6, 68.4, 31.9, 29.8, 22.5 and 14.1.

2.5. Synthesis of 4-((3-formylphenoxy)carbonyl)phenyl 4-decyloxybenzoate (7c)

The 4-((3-formylphenoxy)carbonyl)phenyl 4-decyloxybenzoate was synthesized by

esterification reaction of 4-(4'-decyloxybenzoyloxy)benzoic acid (3.98g, 0.01 mol),

DCC (2.47g, 0.012 mol) with 3-hydroxybenzaldehyde (1.22g, 0.01mol), 5 wt % of DMAP

(0.049g) in dry dichloromethane (50 ml) and reaction mixture was stirred for 12 h. After

completion of reaction, the precipitated N, N′-9-dicyclohexylurea was filtered, washed with

excess of dichloromethane and filtrate concentrated in a rotary evaporator. The residue was

purified by silica gel column using chloroform as eluent. (Yield: 4.17g, 83%).

7c : C31H34O6: Calcd C, 74.08; H, 4.82; O, 19.10; found C, 74.11; H, 4.81; O, 21.08. FT-

IR (KBr pellet, cm-1): 2912, 2855, 1736, 1603, 1412, 1261. 1H NMR (CDCl3, 400 MHz) δ (ppm):

9.81 (s, 1H, -CHO), 8.21-8.09 (d, J=8Hz, 4H, Ar-H), 7.71 (d, J=8Hz, 1H, Ar-H), 7.51 (s, 1H,

Ar-H), 7.48 (t, J=8Hz, 1H, Ar-H), 7.42 (d, J=8Hz, 1H, Ar-H), 7.31 (d, J=8Hz, 2H, Ar-H), 6.91

(d, J=8.4Hz, 2H, Ar-H), 3.78 (t, 2H, -OCH2), 1.89 (m, 2H, -CH2-), 1.33-1.27 (m, 14H, -CH2-),

0.89 (t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz) δ (ppm): 192.1, 165.4, 162.3, 156.4, 151.9,

138.2, 130.7, 130.1, 128.6, 121.9, 113.1, 68.5, 31.7, 29.4, 22.1 and 14.1.

2.5. Synthesis of 4-((3-formylphenoxy)carbonyl)phenyl 4-dodecyloxybenzoate (7d)

The 4-((3-formylphenoxy)carbonyl)phenyl 4-dodecyloxybenzoate was synthesized by

esterification reaction of 4-(4'-dodecyloxybenzoyloxy)benzoic acid (4.26g, 0.01 mol),

DCC (2.47g, 0.012 mol) with 3-hydroxybenzaldehyde (1.22g, 0.01mol), 5 wt % of DMAP

(0.5g) in dry dichloromethane (50 ml) and reaction mixture was stirred for 12 h. After

completion of reaction, the precipitated N, N′-9-dicyclohexylurea was filtered, washed with

excess of dichloromethane and filtrate concentrated in a rotary evaporator. The residue was

purified by silica gel column using chloroform as eluent. (Yield: 4.54g, 86%).

7d : C33H38O6: Calcd C, 74.69; H, 7.22; O, 18.09; found C, 74.58; H, 7.81; O, 17.61. FT-

IR (KBr pellet, cm-1): 2921, 2855, 1734, 1611, 1412, 1261. 1H NMR (CDCl3, 400 MHz) δ (ppm):

9.88 (s, 1H, -CHO), 8.21-8.05 (d, J=8Hz, 4H, Ar-H), 7.75 (d, J=8Hz, 1H, Ar-H), 7.53 (s, 1H,

Ar-H), 7.50 (t, J=8Hz, 1H, Ar-H), 7.44 (d, J=8Hz, 1H, Ar-H), 7.32 (d, J=8Hz, 2H, Ar-H), 6.94

(d, J=8.4Hz, 2H, Ar-H), 4.01 (t, 2H, -OCH2), 1.89 (m, 2H, -CH2-), 1.33-1.28 (m, 18H, -CH2-),

0.91(t, 3H, -CH3). 13C NMR (CDCl3, 400 MHz) δ (ppm): 192.3, 165.3, 162.1, 156.4, 151.3,

137.3, 130.1, 129.1, 127.6, 121.4, 113.1, 67.3, 31.5, 29.7, 23.1 and 14.1.

2.6. Synthesis of 3-(4-(4'-hexyloxybenzoyloxy)benzoyloxy)phenyl4-((4-(4-

hexyloxyphenylazo)phenylimino)methyl)benzoate (8a)

A typical procedure for the synthesis of 8a-8d is as follows:

4-(4'-hexyloxyphenylazo) aniline (1.9g, 0.0064 mol) and 3-(4-(4'-hexyloxybenzoyloxy)

benzoyloxy)phenyl-4-formylbenzoate (2.84g, 0.0064 mol) was dissolved in ethanol (50 mL) then

reaction mixture refluxed until yellow color product precipitated out. After completion of

reaction, the desired product was filtered and washed with ethanol, then recrystallized from

ethanol to get yellowish brown powder (Yield: 3.29g, 71%). A similar procedure was adopted

for preparation of other even numbered alkyl series such as octyl, decyl and dodecyl (8b-8d)

derivatives.

8a: C44H47N3O6: Calcd. C, 74.46; H, 6.53; N, 5.79; O, 13.22; found C, 74.31; H, 6.48; N,

5.79; O, 13.42. FT-IR; 3471, 2922, 2852, 1734, 1602, 1474, 1413, 1253, 1116; 1H- NMR

(CDCl3, 400 MHz), δ (ppm): 8.59 (s, H, -CH=N-), 8.30-8.19 (d, J=8Hz, 4H, Ar-H), 7.95(d,

J=8Hz, 2H, Ar-H), 7.81(d, J=8Hz, 2H, Ar-H), 7.60 (q, J1=4Hz, J2=8Hz, 1H, Ar-H), 7.53 (d, 2H,

Ar-H), 7.51 (s, 1H, Ar-H), 7.40 (t, J=8Hz, 1H, Ar-H), 7.30 (d, J=8Hz, 2H,-Ar-H), 7.28 (m, 1H,

Ar-H), 6.98-6.72 (dd, J=8Hz, 4H, Ar-H), 4.08 (m, 4H, -OCH2-), 1.85 (d, 4H, -CH2-),1.33-1.28

(m, 12H, -CH2-), 0.89 (t, 6H, -CH3). 13C NMR (CDCl3, 400 MHz): 166.5, 165.3, 158.9, 156.3,

151.2, 148.1, 142.1, 135.8, 131.8, 129.8, 127.4, 124.4, 122.6, 121.9, 119.4, 118.1, 64.6, 33.9,

27.9, 22.4, 19.4 and 14.1.

2.6. Synthesis of 3-(4-(4'-octyloxybenzoyloxy)benzoyloxy)phenyl4-((4-(4-

octyloxyphenylazo)phenylimino)methyl)benzoate (8b)

4-(4'-8-octyloxyphenylazo) aniline (2.08g, 0.0064 mol) and 3-(4-(4'-octyloxybenzoyloxy)

benzoyloxy)phenyl-4-formylbenzoate (3.03g, 0.0064 mol) was dissolved in ethanol (50 mL) then

reaction mixture refluxed until yellow color product precipitated out. After completion of

reaction, the desired product was filtered and washed with ethanol, then recrystallized from

ethanol to get yellowish brown powder (Yield: 3.65g, 73%).

8b: C49H55N3O6: Calcd. C, 75.26; H, 7.09; N, 5.37; O, 12.28; found C, 75.31; H, 7.08; N,

5.47; O, 12.14. FT-IR; 3464, 2935, 2854, 1733, 1605, 1474, 1411, 1251, 1116; 1H- NMR

(CDCl3, 400 MHz), δ (ppm): 8.55 (s, H, -CH=N-), 8.31-8.19 (d, J=8Hz, 4H, Ar-H), 7.94(d,

J=8Hz, 2H, Ar-H), 7.83(d, J=8Hz, 2H, Ar-H), 7.61 (q, J1=4Hz, J2=8Hz, 1H, Ar-H), 7.53 (d, 2H,

Ar-H), 7.53 (s, 1H, Ar-H), 7.41 (t, J=8Hz, 1H, Ar-H), 7.30 (d, J=8Hz, 2H,-Ar-H), 7.27 (m, 1H,

Ar-H), 6.98-6.71 (dd, J=8Hz, 4H, Ar-H), 4.01 (m, 4H, -OCH2-), 1.88 (d, 4H, -CH2-),1.33-1.28

(m, 20H, -CH2-), 0.89 (t, 6H, -CH3). 13C NMR (CDCl3, 400 MHz): 165.4, 159.9, 156.4, 151.1,

148.5, 144.1, 135.1, 132.6, 128.9, 127.3, 124.4, 122.1, 121.5, 119.1, 118.5, 66.5, 33.1, 27.4, 22.1,

18.1 and 14.0.

2.6. Synthesis of 3-(4-(4'-decyloxybenzoyloxy)benzoyloxy)phenyl4-((4-(4-

decyloxyphenylazo)phenylimino)methyl)benzoate (8c)

4-(4'-decyloxyphenylazo) aniline (2.25g, 0.0064 mol) and 3-(4-(4'-

decyloxybenzoyloxy)benzoyloxy)phenyl-4-formylbenzoate (3.21g, 0.0064 mol) was dissolved in

ethanol (50 mL) then reaction mixture refluxed until yellow color product precipitated out. After

completion of reaction, the desired product was filtered and washed with ethanol, then

recrystallized from ethanol to get yellowish brown powder (Yield: 4.02g, 75%).

8c: C53H63N3O6: Calcd. C, 75.96; H, 7.58; N, 5.01; O, 12.28; found C, 75.81; H, 7.68; N,

5.10; O, 11.41. FT-IR; 3461, 2933, 2854, 1734, 1604, 1464, 1411, 1251, 1115; 1H- NMR

(CDCl3, 400 MHz), δ (ppm): 8.55 (s, H, -CH=N-), 8.32-8.17 (d, J=8Hz, 4H, Ar-H), 7.93(d,

J=8Hz, 2H, Ar-H), 7.80(d, J=8Hz, 2H, Ar-H), 7.64 (q, J1=4Hz, J2=8Hz, 1H, Ar-H), 7.56 (d, 2H,

Ar-H), 7.50 (s, 1H, Ar-H), 7.41 (t, J=8Hz, 1H, Ar-H), 7.32 (d, J=8Hz, 2H,-Ar-H), 6.98 (m, 1H,

Ar-H), 6.88-6.72 (dd, J=8Hz, 4H, Ar-H), 3.98 (m, 4H, -OCH2-), 1.81 (d, 4H, -CH2-),1.33-1.27

(dd, 36H, -CH2-), 0.89 (t, 6H, -CH3). 13C NMR (CDCl3, 400 MHz): 165.1, 160.1, 155.4, 151.3,

147.3, 142.4, 135.1, 131.3, 128.8, 127.4, 125.4, 122.1, 121.4, 119.1, 118.5, 66.5, 33.5, 28.1, 21.3,

18.4 and 13.8.

2.6. Synthesis of 3-(4-(4'-dodecyloxybenzoyloxy)benzoyloxy)phenyl4-((4-(4-

dodecyloxyphenylazo)phenylimino)methyl)benzoate (8d)

4-(4'-dodecyloxyphenylazo)aniline (2.44g, 0.0064 mol) and 3-(4-(4'-

dodecyloxybenzoyloxy)benzoyloxy)phenyl-4-formylbenzoate (3.39g, 0.0064 mol) was dissolved

in ethanol (50 mL) then reaction mixture refluxed until yellow color product precipitated out.

After completion of reaction, the desired product was filtered and washed with ethanol, then

recrystallized from ethanol to get yellowish brown powder (Yield: 4.06g, 71%).

8d: C57H71N3O6: Calcd. C, 76.56; H, 8.0; N, 4.74; O, 10.74; found C, 76.55; H, 7.88; N,

4.79; O, 10.78. FT-IR; 3473, 2925, 2852, 1731, 1606, 1474, 1413, 1253, 1115; 1H- NMR

(CDCl3, 400 MHz), δ (ppm): 8.53 (s, H, -CH=N-), 8.31-8.19 (d, J=8Hz, 4H, Ar-H), 7.96(d,

J=8Hz, 2H, Ar-H), 7.88 (d, J=8Hz, 2H, Ar-H), 7.61 (q, J1=4Hz, J2=8Hz, 1H, Ar-H), 7.53 (d, 2H,

Ar-H), 7.51 (s, 1H, Ar-H), 7.43 (t, J=8Hz, 1H, Ar-H), 7.31 (d, J=8Hz, 2H,-Ar-H), 7.28 (m, 1H,

Ar-H), 6.99-6.72 (dd, J=8Hz, 4H, Ar-H), 4.03 (m, 4H, -OCH2-), 1.81 (d, 4H, -CH2-),1.33-1.28

(m, 36H, -CH2-), 0.89 (t, 6H, -CH3). 13C NMR (CDCl3, 400 MHz): 165.2, 160.9, 155.4, 151.1,

145.8, 143.4, 135.2, 131.8, 129.3, 128.1, 123.8, 122.7, 121.3, 118.7, 114.3, 64.5, 33.7, 27.8, 22.3,

19.4 and 14.3.

S. 1 Microphotographs of B2 phase in 8d under the application of +75 V (D.C. electric fields, sample thickness 8 μm, temperature 133 ºC).

S. 2 Microphotographs of B2 phase in 8d under the application of -75 V (D.C. electric fields, sample thickness 8 μm, temperature 133 ºC).

S. 3 Microphotographs of B2 phase in 8d under the application of 0 V (D.C. electric fields, sample thickness 8 μm, temperature 133 ºC).

S. 4 Absorption spectra of compound 9 with different exposure time of UV light.

S. 5 Absorption spectra of compound 10 with different exposure time of UV light.