Discotic liquid crystals of transition metal complexes, 53?: Synthesis and mesomorphism of phthalocyanines substituted by m -alkoxyphenylthio groups

Journal of Porphyrins and Phthalocyanines

J. Porphyrins Phthalocyanines 2017; 21: 1–20

DOI: 10.1142/S1088424617500389

Published at http://www.worldscinet.com/jpp/

Discotic liquid crystals of transition metal complexes, 53^†:

synthesis and mesomorphism of phthalocyanines

substituted by m-alkoxyphenylthio groups

Yoshiaki Chino^a, Kazuchika Ohta*^a◊, Mutsumi Kimura^band MikioYasutake^c

^aSmart Material Science and Technology, Interdisciplinary Graduate School of Science and Technology,

Shinshu University, 1-15-1 Tokida, Ueda, 386-8567, Japan

^bDivision of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University,

Ueda 386-8567, Japan

^cComprehensive Analysis Center for Science, Saitama University, 255 Shimo-Okubo, Sakura-Ku,

Saitama 338-8570, Japan

Received 5 March 2017

Accepted 29 March 2017

ABSTRACT: We have successfully synthesized a series of novel octakis(m-alkoxyphenylthio)

phthalocyaninato copper(II) complexes, (m-C_nOPhS)₈PcCu (n = 2, 4, 6, 8, 10, 12, 14, 16: 1b~1i), by our

developed method to reveal their mesomorphism. The phase transition behavior and mesophase structures

have been established by using a polarizing optical microscope, a differential scanning calorimeter, and

a temperature-dependent small angle X-ray diffractometer. Interestingly, the very short chain-substituted

derivatives, (m-C₁OPhS)₈PcCu (1a) and (m-C₂OPhS)₈PCu (1b), show a hexagonal ordered columnar

(Col_ho) mesophase, whereas each of the other longer-chain-substituted derivatives, (m-C_nOPhS)₈PcCu

(n = 4~16: 1c~1i), shows only rectangular ordered columnar (Col_ro) mesophase(s). In contrast to the

present longer-chain-substituted phenylthio derivatives, each of the previous longer-chain-substituted

phenoxy derivatives, (m-C_nOPhO)₈PcCu (n = 10–20), shows a different columnar mesophase of Col_ho.

We discuss this difference of mesomorphism from the viewpoint of the different steric hindrance originated

by the peripheral substituents, PhO and PhS groups. Moreover, we could estimate the optical band gaps of

(m-C₁₀OPhO)₈PcCu and (m-C₁₀OPhS)₈PcCu (1f) from absorption edge of the Q-bands to be 1.79 eV and

1.70 eV, respectively. Therefore, the phenylthio-substituted derivative gave a narrower band gap by ca.

0.1 eV in comparison with the phenoxy-substituted derivative.

KEYWORDS: phthalocyanine, metallomesogen, columnar mesophase, liquid crystals.

chains in the periphery [2]. When these discogens are

INTRODUCTION

heated, the peripheral long alkyl chains ﬁrstly melt to form

Sincetheﬁrstdiscoticcolumnarliquidcrystalwasfound

soft parts, but the central rigid cores maintain columnar

by Chandrasekhar and co-workers in 1977 [1], various

discogens have been synthesized up to date. In general,

a columnar liquid crystal has a p-conjugated macrocyclic

stacking structure due to their strong p–p interaction.

Accordingly, columnar liquid crystalline phases can be

induced by this special situation. Therefore, pre-melting of

core such as triphenylene, hexabenzocoronene and phthal-

the long alkyl chains by heating is driving force to induce

ocyanine (Pc), together with more than six long alkyl

liquid crystalline phases. In addition, since p orbitals of

the p-conjugated macrocyclic cores are overlapped in

^◊SPP full member in good standing

one-dimensional columns formed by self-assembly, high

charge carrier mobility along the columnar axis may

be achieved. Therefore, the columnar liquid crystalline

compounds exhibiting high charge carrier mobilities

*Correspondence to: Kazuchika Ohta, email: ko52517@

shinshu-u.ac.jp, tel/fax: +81 268-21-5492

^†Part 52: Ref. 45 in this paper.

2

Y. CHINO ET AL.

Fig. 1. Molecular formulae of liquid crystals based on phthalocyanine. *1: [8, 9, 21]. *2: [20]

have attracted a lot of our attention to apply to organic

semiconducting devices such as organic photovoltaic

cell, organic ﬁeld effect transistor and so on [3]. In our

previous works [4–6], we synthesized columnar liquid

crystalline phthalocyanine compounds, (C₁₂H₂₅O)₈PcH₂

and (C₁₂H₂₅S)₈PcH₂, illustrated in Fig. 1. The hexagonal

ordered columnar (Col_ho) phases in (C₁₂H₂₅O)₈PcH₂and

(C₁₂H₂₅S)₈PcH₂exhibited high charge carrier mobilities of

0.051 cm²/Vs and 0.28 cm²/Vs, respectively. Therefore,

the alkylthio(RS)-substituted phthalocyanine derivative

gives about ﬁve times higher charge carrier mobility than

the alkoxy(RO)-substituted phthalocyanine derivative. In

order to achieve much higher charge carrier mobility in

columnar liquid crystalline Pc compounds, the following

two points may be furthermore required:

derivatives, (m-C_nOPhO)₈PcCu (Fig. 1), satisfying the

above two requirements. Therefore, if we can synthesize

columnar liquid crystalline phthalocyanines substituted

by m-alkoxyphenylthio(m-C_nOPhS) groups instead of

m-alkoxyphenoxy(m-C_nOPhO) groups, higher charge

carrier mobility may be realized.The alkylthio-substituted

phthalocyanine derivative, (C_nS)₈PcH₂, exhibits ﬁve times

higher charge carrier mobility than the alkoxy-substituted

phthalocyanine derivative, (C_nO)₈PcH₂, as mentioned

above [4–6]. Therefore, we can expect similarly that

the phenylthio-substituted derivative, (PhS)₈PcCu, may

exhibit higher charge carrier mobility than the phenoxy-

substituted derivative, (PhO)₈PcCu. Although the

(PhS)₈PcCu derivatives have been reported so far [9–19],

no liquid crystalline (PhS)₈PcCu derivatives have been

reported.

(1) to show very short intracolumnar stacking distance,

(2) to exhibit highly ordered alignment (ideally, homeo-

tropic alignment).

Recently, we have synthesized (PhS)₈PcCu com-

plexes having very short methoxy groups at the o-, m-,

m- & p-positions of the phenylthio group to induce

mesomorphisminspiteoftheabsenceoflongalkoxychains

[20]. The thermal ﬂuctuation of the bulky substituents

by heating makes soft parts to induce liquid crystalline

In our previous works [7, 8], we found that substitu-

tion of m-alkoxyphenoxy (m-C_nOPhO) groups at the

b-positions of Pc gave columnar liquid crystalline

J. Porphyrins Phthalocyanines 2017; 21: 2–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

3

phases. Hence, they are categorized to “ﬂying-seed-like”

recorded by using a Hitachi U-4100 spectrophotometer.

UV-vis spectral data of the (m-C_nOPhS)₈PcCu complexes

synthesized in this study were summarized in Table 2.

Thermal gravimetric analysis (TGA) was carried out

with a Rigaku Thermo Plus TG8120 thermal gravity

analyzer. All TGA were performed under N₂atmosphere.

Phase transition behavior of the present complexes was

observed with a polarizing optical microscope (Nikon

ECLIPSE E600 POL; magniﬁcations of the objective

and ocular lenses were × 10, respectively) equipped

with a Mettler FP82HT hot stage and a Mettler FP-90

Central Processor, and a Shimadzu DSC-50 differential

scanning calorimeter. The phase transition temperatures

and enthalpy changes are listed in Table 3. The

mesophases were identiﬁed by using a small angle X-ray

diffractometer (Bruker Mac SAXS System) equipped

with a temperature-variable sample holder adopted a

Mettler FP82HT hot stage.

liquid crystals [21–25]. However, these ﬂying-seed-like

liquid crystals (x-C₁OPhS)₈PcCu substituted by very short

alkoxy groups are not suitable for application to organic

semiconductor, because they show mesomorphism only at

extremely high temperatures and transform into isotropic

liquid with accompanying decomposition. Therefore, we

have planned to synthesize new long n-alkoxy-substituted

(m-C_nOPhS)₈PcCu derivatives showing mesomorphism

from room temperature and clearing into isotropic liquid

without decomposition.

In this study, we have developed the synthetic route of the

new phenylthio-substituted derivatives, (m-C_nOPhS)₈PcCu

(n = 2–16: 1b–1i in Fig. 1), having long n-alkoxy groups at

the m-position, in order to investigate their mesomor-

phism and mesomorphic structures. In comparison with the

previous phenoxy-substituted Pc derivatives, (m-C_nOPhO)₈-

PcCu (n = 10–20), we discuss the difference of meso-

morphism from the viewpoint of the different steric

hindrance originated by the peripheral PhO and PhS groups.

Synthesis

Schemes 1 and 2 illustrate synthetic routes for the

precursors of m-alkoxythiophenol (4b~4i) and the corres-

ponding liquid crystalline Pc derivatives (m-C_nOPhS)_8-

PcCu (1b~1i), respectively. All reactions were carried out

under nitrogen atmosphere.

EXPERIMENTAL

Materials

The chemical reagents of 3-hydroxybenzenethiol, tri-

tylchloride, Et₃SiH, 3-iodophenol, n-alkylbromide, NaBH₄

and 4,5-dichlorophthalonitrile were purchased from Tokyo

Chemical Industry and used without further puriﬁcations.

Other reagents were purchased from Wako Pure Chemical

Industries and used without further puriﬁcations. Thin

layer chromatography sheet (TLC) and silica gel were

purchased from Merck. All reaction solvents were

purchased fromWako Pure Chemical Industries. DMF was

pre-dried over KOH and distilled over CaH₂under reduced

pressure and stored in the presence of 4A molecular sieves.

THF was pre-dried over CaCl₂and distilled from Na wire/

benzophenone kethyl. 1-Hexanol was used without further

puriﬁcations. Deuterated chloroform and DMSO for NMR

measurements were purchased from Merck and WAKO

Pure Chemical Industries, respectively. Abbreviations of

reagents and solvents were as follows:

[Route (a)]

3-Triphenylmethylsulfanylphenol (2A). (Scheme 1)

Synthetic method was adopted [26]. A three necked ﬂask

dried was charged with 3-hydroxybenzenethiol (1.03 g,

8.15 mmol) and dry pyridine (0.679 g, 8.58 mmol). Trityl

chloride (2.27 g, 8.14 mmol) was added to the reaction

mixture and it was stirred at rt for 3.5 h. When TLC (SiO₂/

AcOEt:n-hexane = 1:1) conﬁrmed disappearance of the

spot of the starting reagent of 3-hydroxybenzenethiol

(R_f= 0.50) and appearance of the target compound (R_f=

0.68), the reaction was terminated. The reaction mixture

wasdilutedwithwaterandextractedwithdichloromethane.

The organic layer was washed with water three times and

saturated brine once. The organic layer was collected and

dried over Na₂SO₄overnight. Na₂SO₄was ﬁltrated off and

dichloromethane and pyridine were evaporated in vacuo.

The residue was dried in vacuo to obtain colorless oil

DBU:1,8-diazabicyclo[5.4.0]-7-undecene,DMF:N,N-

dimethylformamide,THF:tetrahydrofuran,DMSO:dime-

thylsulfoxid and TFA: triﬂuoroacetic acid.

1

(0.268 g). Yield 85.6%. H NMR (400 MHz, d₆-DMSO,

TMS): d, ppm 9.31 (brs, 1H, -OH), 7.33–7.20 (m, 15H,

ArH), 6.83 (t, J = 8.0 Hz, 1H, ArH), 6.55–6.52 (m, 1H,

ArH), 6.39–6.38 (m, 1H, ArH), 6.32–6.30 (m, 1H, ArH).

1-Decyloxy-3-triphenylmethylsulfanylbenzene

(3Af). (Scheme 1) Three necked ﬂask dried was charged

with 3-triphenylmethylsulfanylphenol (2A: 0.505 g, 1.37

mmol), Cs₂CO₃(0.564 g, 1.73 mmol) and dry DMF (5 mL)

at rt. 1-Bromodecane (0.315 g, 1.42 mmol) was added

to the reaction mixture and stirred at rt for 4.5 h.

When TLC (SiO₂/AcOEt:n-hexane = 1:1) conﬁrmed

disappearance of the spot of starting reagent (R_f= 0.18)

of 2A and appearance of the target compound (3Af)

(R_f= 0.63), the reaction was terminated. The reaction

Measurements

The ¹H NMR measurements were carried out by using

a Bruker Ultrashield 400 MHz. The MALDI-TOF mass

spectral measurements were carried out by using a Bruker

Daltonics Autoﬂex III spectrometer (matrix: dithranol).

TheelementalanalyseswereperformedbyusingaPerkin-

Elmer Elemental Analyzer 2400. The data of MALDI-

TOF mass spectra and elemental analyses are listed in

Table 1. Electronic absorption (UV-vis) spectra were

J. Porphyrins Phthalocyanines 2017; 21: 3–20

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Y. CHINO ET AL.

J. Porphyrins Phthalocyanines 2017; 21: 4–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

5

Table 2. UV-vis spectral data in CHCl₃solution of (m-C_nOPhO)₈PcCu (1b~1i)

Compound

Concentration (X10^-6mol L^-1)

l/nm (loge)

Q-band

Soret band

Q_0–1-band

Q_0–0-band

1b: (m-C₂OPhS)₈PcCu

1c: (m-C₄OPhS)₈PcCu

1d: (m-C₆OPhS)₈PcCu

1e: (m-C₈OPhS)₈PcCu

1f: (m-C₁₀OPhS)₈PcCu

1g: (m-C₁₂OPhS)₈PcCu

1h: (m-C₁₄OPhS)₈PcCu

1i: (m-C₁₆OPhS)₈PcCu

2.32

2.39

2.26

2.29

2.42

2.34

2.37

344.0 (4.91)

344.0 (4.92)

344.0 (4.93)

345.5 (4.90)

342.0 (4.88)

344.0 (4.88)

344.0 (4.89)

642.0 (4.68)

642.0 (4.69)

642.0 (4.70)

643.0 (4.65)

642.0 (4.66)

642.0 (4.65)

718.0 (5.42)

716.0 (5.42)

718.0 (5.43)

718.0 (5.44)

718.9 (5.42)

718.0 (5.40)

718.0 (5.38)

Table 3. Phase transition temperatures and enthalpy changes of 1b~1i

mixture was diluted with water and extracted with

dichloromethane. The organic layer was washed with

water three times and saturated brine once. The organic

layer was collected and dried over Na₂SO₄overnight.

Na₂SO₄was ﬁltrated off and dichloromethane was

evaporated in vacuo to obtain the crude product. It was

puriﬁed by silica gel column chromatography (R_f= 0.55,

CH₂Cl₂:n-hexane = 1:2). The solvents were evaporated in

vacuo and resulting product was dried in vacuo to obtain

colorless oil (0.598 g). Yield 85.8%. ¹H NMR (400 MHz,

d₆-DMSO, TMS): d, ppm 7.35–7.21 (m, 15H, ArH), 6.98

(t, J = 7.9 Hz, 1H, ArH), 6.71, 6.70 (dd, J = 2.4, 6.0 Hz,

1H, ArH), 6.59 (d, J = 7.8 Hz, 1H, ArH), 6.32–6.31 (m,

1H, ArH), 3.58 (t, J = 6.6 Hz, 2H, -OCH₂-), 1.53 (quin,

J. Porphyrins Phthalocyanines 2017; 21: 5–20

6

Y. CHINO ET AL.

Scheme 1. Synthetic routes (a), (b) and (c) for 3-alkoxybenzenethiol: (a) by using the methods adopted [26] and [27]; (b) [30]; (c) [31]

OR

4,5-dichlorophthalonitrile

K₂CO₃

S

CN

DMF

90°C

SH

4a~i

R=C_nH_2n+1

n=1 (a)

2 (b)

5a~i

OR

4 (c)

6 (d)

RO

OR

8 (e)

10 (f)

S

12 (g)

14 (h)

16 (i)

OR

N

S

DBU, CuCl₂

N

Cu

S

N

1-hexanol

reflux

N

OR

S

RO

OR

1a~i

Scheme 2. Synthetic route for (m-C_nOPhS)₈PcCu (1a~1i). 1a: previous work [20]

J. Porphyrins Phthalocyanines 2017; 21: 6–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

7

J = 6.4 Hz, 2H, -OCCH₂-), 1.32–1.20 (m, 14H, -CH₂-

ArH), 3.92 (t, J = 6.4 Hz, 2H, -OCH₂-), 1.75 (quin,

J = 7.0 Hz, 2H, -OCCH₂-), 1.48 (sext, J = 7.4 Hz, 2H,

-OCCCH₂-), 0.969 (t, J = 7.2 Hz, 3H, -CH₃).

× 7), 0.857 (t, J = 6.7 Hz, 3H, -CH₃).

3-Decyloxybenzenethiol (4f). (Scheme 1) Synthetic

method was adopted [27]. A three necked ﬂask was

chargedwithtriﬂuoroaceticacid(3mL),1-decyloxy-3-tri-

phenylmethylsulfanylbenzene (3Af: 0.598 g, 1.18 mmol),

CH₂Cl₂(1.1 mL) and Et₃SiH (0.487 g, 4.19 mmol).

It was stirred at rt for 30 min. The reaction mixture

was concentrated in vacuo and diluted with water and

extracted with dichloromethane. The organic layer was

washed with water three times and saturated brine once.

The organic layer was collected and dried over Na₂SO₄

overnight. Na₂SO₄was ﬁltrated off and dichloromethane

was evaporated in vacuo. Even by using any puriﬁcation

techniques, it was not possible to separate the target

compound and the by-compound containing deprotection

trityl group. Therefore, the synthesis of 4f by Route A

was abandoned. Next, synthesis of 4b~4i by Route B in

Scheme 1 was carried out.

3-Octyloxyiodobenzene (2Be). Yield 92.2%. ¹H

NMR (400 MHz, CDCl₃, TMS): d, ppm 7.20–7.17 (m,

2H, ArH), 6.91 (t, J = 7.8 Hz, 1H, ArH), 6.79–6.77 (m,

1H, ArH), 3.84 (t, J = 6.6 Hz, 2H, -OCH₂-), 1.69 (quin,

J = 7.2 Hz, 2H, -OCCH₂-), 1.40–1.20 (m, 10H, -(CH₂)₅-),

0.818 (t, J = 7.0 Hz, 3H, -CH₃). The ¹H NMR datum was

in accordance with Ref. 29.

3-Decyloxyiodobenzene (2Bf). Yield 93.9%. ¹H

NMR (400 MHz, CDCl₃, TMS): d, ppm 7.30–7.27 (m,

2H, ArH), 7.04 (t, J = 8.2 Hz, 1H, ArH), 6.89–6.87 (m,

1H, ArH), 3.97 (t, J = 6.4 Hz, 2H, -OCH₂-), 1.85 (quin,

J = 6.6 Hz, 2H, -OCCH₂-), 1.50–1.30 (m, 14H, -(CH₂)₇-),

0.946 (t, J = 7.0 Hz, 3H, -CH₃).

1

3-Dodecyloxyiodobenzene (2Bg). Yield 85.2%. H

NMR (400 MHz, CDCl₃, TMS): d, ppm 7.26–7.24 (m,

2H, ArH), 6.97 (t, J = 7.8 Hz, 1H, ArH), 6.86–6.83 (m,

1H, ArH), 3.91 (t, J = 6.6 Hz, 2H, -OCH₂-), 1.75 (quin,

J = 7.0 Hz, 2H, -OCCH₂-), 1.45–1.27 (m, 18H, -(CH₂)₉-),

0.881 (t, J = 7.0 Hz, 3H, -CH₃).

[Route (b)]

3-Ethoxyiodobenzene (2Bb). (Scheme 1) A three

necked ﬂask dried was charged with K₂CO₃(1.89 g,

13.7 mmol), 3-iodophenol (1.00 g, 4.55 mmol) and dry

DMF (5 mL). Ethylbromide (0.595 g, 5.46 mmol) was

then added to the reaction mixture and it was stirred at

90°C. Proceeding of the reaction was monitored by TLC

(SiO₂/n-hexane). After 1 h, disappearance of the spot

of 3-iodophenol (R_f= 0.0) was conﬁrmed, so that the

reaction was quenched with water and cooled to rt. The

product was extracted with ethyl acetate and the organic

layer was washed with water three times and saturated

brine once. The organic layer was collected and dried

over Na₂SO₄overnight. Na₂SO₄was ﬁltrated off and

the solvent was evaporated in vacuo to obtain yellowish

liquid (1.06 g). Yield 93.8%. The product was used for

3-Tetradecyloxyiodobenzene (2Bh). Yield 84.1%.

¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.27–7.24 (m,

2H, ArH), 6.97 (t, J = 8.0 Hz, 1H, ArH), 6.86–6.84 (m,

1H, ArH), 3.91 (t, J = 6.4 Hz, 2H, -OCH₂-), 1.75 (quin,

J = 6.6 Hz, 2H, -OCCH₂-), 1.47–1.26 (m, 22H, -(CH₂)₁₁-),

0.88 (t, J = 7.0 Hz, 3H, -CH₃).

3-Hexadecyloxyiodobenzene (2Bi). Yield 83.3%,

1

mp 32.4°C. H NMR (400MH, CDCl₃, TMS): d, ppm

7.27–7.23 (m, 2H, ArH)), 6.98 (t, J = 8.0 Hz, 1H, ArH),

6.86–6.83 (m,1H, ArH), 3.91 (t, J = 6.6 Hz, 2H, -OCH₂-),

1.76 (quin, J = 7.0 Hz, 2H, -OCCH₂-), 1.43 (quin, J = 7.3

Hz, 2H, -OCCCH₂-), 1.33–1.26 (m, 24H, -CH₂- × 12),

0.88 (t, J = 6.8 Hz, 3H,-CH₃).

1

the next reaction without further puriﬁcation. H NMR

3-Ethoxybenzenthiol (4b). (Scheme 1) Synthetic

method was adopted [30]. A three necked ﬂask dried

was charged with K₂CO₃(1.00 g, 7.26 mmol), powdered

sulfur (0.358 g, 11.2 mmol), CuI (72.3 mg, 0.380 mmol),

3-ethoxyiodebenzene (2Bb) (0.897 g, 3.62 mmol) and

dry DMF (4 mL). The reaction was carried out at 90°C

with stirring for 12 h. TLC (SiO₂/n-hexane) conﬁrmed

disappearance of the spot of starting reagent of 2Bb

(Rf = 0.30) and appearance of the new spot (Rf = 0.0)

were conﬁrmed by TLC. The reaction mixture was cooled

to rt and diluted with water. The product was extracted

with ethyl acetate and the organic layer was washed with

water three times and saturated brine once. The organic

layer was collected and dried over Na₂SO₄overnight.

Na₂SO₄was ﬁltrated off and the solvent was evaporated

in vacuo to obtain the crude product, which was used

for next reaction without further puriﬁcation. The three

necked ﬂask containing the crude product was charged

with NaBH₄(4.24 g, 112 mmol) and dry THF (10 mL)

and it was stirred for 32 h. The reaction was quenched

with slowly dropwise adding conc. HCl in an ice bath. The

product was extracted with ethyl acetate and the organic

(400 MHz, CDCl₃, TMS): d, ppm 7.27–7.24 (m, 2H,

ArH), 6.98 (t, J = 8.0 Hz, 1H, ArH), 6.86–6.84 (m, J =

2.4 Hz, 8.4 Hz, 1H, ArH), 4.00 (quart, J = 6.9 Hz, 2H,

-OCH₂-), 1.40 (t, J = 7.0 Hz, 3H, -CH₃).

3-Hexyloxyiodobenzene (2Bd). Yield 91.6%. This

synthesis was carried out as the same method of 2Bb.

The crude product was puriﬁed by silica gel column

chromatography (n-hexane/R_f= 0.30) to obtain colorless

1

liquid (1.29 g). H NMR (400 MHz, CDCl₃, TMS): d,

ppm 7.20–7.18 (m, 2H, ArH), 6.90 (t, J = 7.8 Hz, 1H,

ArH), 6.79–6.77 (m, 1H, ArH), 3.84 (t, J = 6.6 Hz, 2H,

-OCH₂-), 1.69 (quin, J = 7.0 Hz, 2H, -OCCH₂-), 1.41–

1.22 (m, 6H, -(CH₂)₃-), 0.835 (t, J = 7.0 Hz, 3H, -CH₃).

¹H NMR datum was in accordance with Ref. 28.

Other homologs 2Bc~2i were synthesized by the same

method for 2Bd. Only the yield and ¹H NMR data were

shown below. All compounds were obtained as liquid

except for 2Bi.

1

3-Butoxyiodobenzene (2Bc). Yield 42.7%. H NMR

(400 MHz, CDCl₃, TMS): d, ppm 7.27–7.25 (m, 2H,

ArH), 6.98 (t, J = 8.0 Hz, 1H, ArH), 6.87–6.84 (m, 1H,

J. Porphyrins Phthalocyanines 2017; 21: 7–20

8

Y. CHINO ET AL.

layer was washed with water three times and saturated

brine once. The organic layer was collected and dried

over Na₂SO₄overnight. Na₂SO₄was ﬁltrated off and

the solvent was evaporated in vacuo to obtain colorless

liquid (0.382 g). The product was used for next reaction

without further puriﬁcations. Yield 68.5%. ¹H NMR (400

MHz, CDCl₃, TMS): d, ppm 7.12 (t, J = 8.0 Hz, 1H, ArH),

6.84–6.81 (m, 2H, ArH), 6.68 (dd, J = 2.0 Hz, 6.0 Hz, 1H,

ArH), 4.00 (quart, J = 7.1 Hz, 2H, -OCH₂-), 3.44 (s, 1H,

-SH), 1.39 (t, J = 7.0 Hz, 3H, -CH₃).

[Route (c)]

Derivative 4i was also synthesized by another method,

see Refs. 31 and 32.

Bis(3-hydroxyphenyl)disulﬁde (2C). (Scheme 1)

In a three neck ﬂask 3-hydroxybenzenethiol (0.247 g,

1.96 mmol) was dissolved in 10 mL of DMSO-CHCl₃

mixed solvent (1:1, v/v). To the reaction mixture, 47 wt%

HBr aq. sol. (72.9 mg, 0.423 mmol) was added and it

was stirred at rt for 12.5 h. When TLC (SiO₂/CHCl₃)

conﬁrmed disappearance of the spot of starting reagent

of 3-hydroxybenzenethiol (R_f= 0.10) and appearance of

a new spot of target compound 2C (R_f= 0.0), the reaction

was terminated. The solvents were evaporated in vacuo

to concentrate the reaction mixture. The product was

extracted with ethyl acetate and washed with water three

times and saturated brine once. The organic layer was

collected and dried over Na₂SO₄overnight. Na₂SO₄was

ﬁltrated off and the solvent was evaporated in vacuo. The

residue was dried in vacuo to obtain the target compound

2C as white powder (0.242 g).Yield 98.5%, mp 80–90°C

Other homologs 4c~4i were synthesized by the same

1

method for 4b. Only the yield and H NMR data were

shown below.All compounds 4c~4i were obtained as liquid.

1

3-Butoxybenzenethiol (4c). Yield 77.9%. H NMR

(400 MHz, CDCl₃, TMS): d, ppm 7.12 (t, J = 8.0 Hz,

1H, ArH), 6.84–6.81 (m, 2H, ArH), 6.68 (dd, J = 3.2 Hz,

7.6 Hz, 1H, ArH), 3.93 (t, J = 6.4 Hz, 2H, -OCH₂-), 3.43

(s, 1H, -SH), 1.75 (quin, J = 7.0 Hz, 2H, -OCCH₂-), 1.48

(sext, J = 7.4 Hz, 2H, -OCCCH₂-), 0.969 (t, J = 7.4 Hz,

3H, -CH₃).

3-Hexyloxybenzenethiol (4d). Yield 65.9%. ¹H NMR

(400 MHz, CDCl₃, TMS): d, ppm 7.05 (t, J = 7.8 Hz,

1H, ArH), 6.76–6.75 (m, 2H, ArH), 6.62–6.60 (m, 1H,

ArH), 3.86 (t, J = 6.6 Hz, 2H, -OCH₂-), 3.36 (s, 1H, -SH),

1.68 (quin, J = 7.1 Hz, 2H, -OCCH₂-), 1.41–1.27 (m, 6H,

-OCCCH₂-), 0.832 (t, J = 6.8 Hz, 3H, -CH₃).

(broad). H NMR (400 MHz, d₆-DMSO, TMS): d, ppm

1

9.75 (s, 2H, -OH), 7.17 (t, J = 8.0 Hz, 2H, ArH), 6.93–

6.90 (m, 4H, ArH), 6.68–6.60 (m, 2H, ArH).

Bis(3-hexadecyloxyphenyl) disulﬁde (3Ci).(Scheme1)

A three necked ﬂask was charged with bis(3-hydroxy-

phenyl)disulﬁde (2C) (0.263 g, 1.05 mmol), K₂CO₃

(0.744 g, 5.38 mmol) and dry DMF (4 mL). 1-Bromo-

hexadecane (0.808 g, 2.64 mmol) was then added to

the reaction mixture and it was stirred at 90°C for

3.5 h. The reaction was terminated when TLC (SiO₂/

CH₂Cl₂) conﬁrmed disappearance of both the spots of

starting reagent of 2C (Rf = 0.0) and monoalkylated

compound (Rf = 0.55), and appearance of only one spot

of dialkylated compound (SiO₂/CH₂Cl₂, Rf = 0.95). The

reaction mixture was diluted with water and the product

was extracted with dichloromethane. The organic layer

was washed with water three times and saturated brine

once. The organic layer was collected and dried over

Na₂SO₄overnight. Na₂SO₄was ﬁltrated off and the

solvent was evaporated in vacuo. The crude product was

recrystallised from acetone and then n-hexane at 25°C to

obtain white powder (0.330 g). Yield 44.9%, mp 62.5°C

(mp1), 64.8°C (mp2). (This compound showed double

melting behavior). ¹H NMR (400 MHz, CDCl₃, TMS): d,

ppm 7.18 (t, J = 8.2 Hz, ArH, 2H), 7.06–7.04 (m, ArH,

4H), 6.75, 6.74 (dd, J = 2.2 Hz, 6.6 Hz, ArH, 2H), 3.90

(t, J = 6.6 Hz, -(OCH₂)- × 2, 4H), 1.74 (quin, J = 7.1 Hz,

-(OCCH₂)- × 2, 4H), 1.45–1.26 (m, -(CH₂)- × 26, 52H),

0.879 (t, J = 6.8 Hz, -CH₃× 2, 6H).

3-Octyloxybenzenethiol (4e). Yield 91.6%. ¹H NMR

(400 MHz, CDCl₃, TMS): d, ppm 7.05 (t, J = 8.0 Hz, 1H,

ArH), 6.76–6.74 (m, 2H, ArH), 6.63–6.60 (m, 1H, ArH),

3.84 (t, J = 6.6 Hz, 2H, -OCH₂-), 3.36 (s, 1H, -SH), 1.69

(quin, J = 7.2 Hz, 2H, -OCCH₂-), 1.40-1.22 (m, 10H,

CH₂× 5), 0.816 (t, J = 7.0 Hz, 3H, -CH₃).

3-Decyloxybenzenethiol (4f). Yield 80.5%. ¹H NMR

(400 MHz, CDCl₃, TMS): d, ppm 7.04 (t, J = 8.0 Hz, 1H,

ArH), 6.79–6.73 (m, 2H, ArH), 6.63–6.59 (m, 1H, ArH),

3.84 (t, J = 6.6 Hz, 2H, -OCH₂-), 3.36 (s, 1H, -SH), 1.75

(quin, J = 7.0 Hz, 2H, -OCCH₂-), 1.41–1.20 (m, 14H,

CH₂× 7), 0.811 (t, J = 6.8 Hz, 3H, -CH₃).

3-Dodecyloxybenzenethiol (4g). Yield 62.3%.

¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.12 (t, J =

8.2 Hz, 1H, ArH), 6.84–6.81 (m, 2H, ArH), 6.70–6.67

(m, 1H, ArH), 3.91 (t, J = 6.6 Hz, 2H, -OCH₂-), 3.43 (s,

1H, -SH), 1.76 (quin, J = 7.0 Hz, 2H, -OCCH₂-), 1.45–

1.27 (m, 18H, CH₂× 9), 0.881 (t, J = 7.0 Hz, 3H, -CH₃).

3-Tetradecyloxybenzenethiol (4h). Yield 92.7%.

¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.12 (t, J =

7.8 Hz, 1H, ArH), 6.84–6.81 (m, 2H, ArH), 6.70–6.67

(m, 1H, ArH), 3.92 (t, J = 6.6 Hz, 2H, -OCH₂-), 3.43 (s,

1H, -SH), 1.76 (quin, J = 7.0 Hz, 2H, -OCCH₂-), 1.47–

1.26 (m, 22H, CH₂× 11), 0.88 (t, J = 6.8 Hz, 3H, -CH₃).

3-Hexadecyloxybenzenethiol (4i). Yield 51.8%.

¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.12 (t, J =

8.2 Hz, 1H, ArH), 6.84–6.81 (m, 2H, ArH), 6.69, 6.68

(dd, J = 2.0 Hz, 6.0 Hz, 1H, ArH), 3.92 (t, J = 6.6 Hz, 2H,

-OCH₂-), 3.44 (s, 1H, -SH), 1.76 (quin, J = 7.0 Hz, 2H,

-OCCH₂-), 1.47–1.26 (m, 26H, -(CH₂)₁₃-), 0.88 (t, J = 6.4

Hz, 3H, -CH₃).

3-Hexadecyloxybenzenthiol (4i). (Scheme 1) Com-

pound 4i was synthesized from compound 3Ci

according to the method used by authors in Ref. 32.

A three necked ﬂask was charged with bis(3-hexadecy-

loxypheny)disulﬁde (3Ci: 0.324 g, 0.464 mmol), PPh₃

(0.299 g, 1.14 mmol) and THF (12 mL) and then conc.

HCl aq. sol. (0.4 mL) and H₂O (2 mL). It was gently

reﬂuxed with stirring for 5 h. After cooled to rt, large

J. Porphyrins Phthalocyanines 2017; 21: 8–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

9

excessive amounts of iodomethane was added to the

4,5-Bis(m-octyloxyphenylthio)phthalonitrile (5e).

SiO₂, CH₂Cl₂:n-hexane = 4:1, R_f= 0.58. Yield 95.1%, mp

72.1°C. ¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.41

(t, J = 8.0 Hz, 2H, ArH), 7.11–7.03 (m, 8H, ArH), 3.98

(t, J = 6.6 Hz, 4H, -OCH₂-), 1.81 (quin, J = 7.1 Hz, 4H,

-OCCH₂-), 1.49–1.24 (m, 20H, (-CH₂-)₅× 2), 0.889 (t,

J = 6.8 Hz, 6H, -CH₃).

4,5-Bis(m-decyloxyphenylthio)phthalonitrile (5f).

SiO₂, CH₂Cl₂, R_f= 0.80. Yield 78.1%, mp 76.5°C.

¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.43 (t,

J = 7.6 Hz, 2H, ArH), 7.13–7.08 (m, 8H, ArH), 4.00 (t,

J = 6.6 Hz, 4H, -OCH₂-), 1.83 (quin, J = 7.4 Hz, 4H,

-OCCH₂-), 1.53–1.31 (m, 28H, (-CH₂-)₇× 2), 0.904 (t,

J = 6.6 Hz, 6H, -CH₃).

reaction mixture and stirred at rt for 9 h. The reaction

mixture was diluted with water and extracted with toluene.

The organic layer was washed with water three times and

saturated brine once. The organic layer was collected and

dried over Na₂SO₄overnight. Na₂SO₄was ﬁltrated off

and the solvent was concentrated in vacuo. n-hexane was

added to the solution until precipitation was occurred.

It was heated until the precipitates were completely

dissolved and then cooled to rt. The resulted precipitates

were removed by ﬁltration. To the ﬁltrate n-hexane was

furthermore added to occur precipitation completely. The

precipitates were removed again by ﬁltration, and then the

ﬁltrate was evaporated in vacuo to remove the solvent to

afford colorless oil (0.151 g). Yield 46.5%. ¹H NMR (400

MHz, CDCl₃, TMS): d, ppm 7.12 (t, J = 8.2 Hz, 1H, ArH),

6.84–6.81 (m, 2H, ArH), 6.69, 6.68 (dd, J = 2.0 Hz, 6.0

Hz, 1H, ArH), 3.92 (t, J = 6.6 Hz, 2H, -OCH₂-), 3.44 (s,

1H, -SH), 1.76 (quin, J = 7.0 Hz, 2H, -OCCH₂-), 1.47–

1.26 (m, 26H, -(CH₂)₁₃-), 0.88 (t, J = 6.4 Hz, 3H, -CH₃).

4,5-Bis(m-dodecyloxyphenylthio)phthalonitrile

(5g). SiO₂, CH₂Cl₂:n-hexane = 4:1, R_f= 0.58. Yield

1

29.3%, mp 76.2°C. H NMR (400 MHz, CDCl₃, TMS):

d, ppm 7.41 (t, J = 8.2 Hz, 2H, ArH), 7.11–7.03 (m, 8H,

ArH), 3.98 (t, J = 6.6 Hz, 4H, -OCH₂-), 1.81 (quin, J =

7.1 Hz, 4H, -OCCH₂-), 1.50–1.21 (m, 36H, (-CH₂-)₉× 2),

0.88 (t, J = 6.8 Hz, 6H, -CH₃).

4,5-Bis(m-ethoxyphenylthio)phthalonitrile

(5b).

Synthetic method was adopted [33]. A three necked

ﬂask was charged with K₂CO₃(0.653 g, 4.73 mmol),

3-ethoxybenzenethiol (3a) (0.234 g, 1.52 mmol) and

DMF (5 mL) and it was heated up to 90°C. To the

reaction mixture, 4,5-dichlorophthalonitrile (0.102 g,

0.517 mmol) was added and stirred at 90°C for 7 h with

occasionally monitoring by TLC. When the reaction was

completed, it was quenched with water. The product was

extracted with ethyl acetate and the organic layer was

washed with water three times and saturated brine once.

The organic layer was collected and dried over Na₂SO₄

overnight. Na₂SO₄was ﬁltrated off and the solvent was

evaporated in vacuo. The crude product was puriﬁed by

column chromatography (SiO₂, CH₂Cl₂, R_f= 0.50) to

obtain white crystals (0.112 g).Yield 50.2%, mp 139.8°C.

¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.41 (t, J =

8.2 Hz, 2H, ArH), 7.12–7.03 (m, 8H, ArH), 4.07 (quart,

J = 7.1 Hz, 4H, -OCH₂-), 1.45 (t, J = 7.0 Hz, 6H, -CH₃).

Other homologs 5c~5i were synthesized by the

same method for 5b. The eluents for the column

4,5-Bis(m-tetradecyloxyphenylthio)phthalonitrile

(5h). SiO₂, CH₂Cl₂:n-hexane = 4:1, R_f= 0.38. Yield

75.0%, mp 50.0°C (mp₁), 83.3°C (mp₂) (this compound

1

showed double melting behavior). H NMR (400 MHz,

CDCl₃, TMS): d, ppm 7.41 (t, J = 7.8 Hz, 2H, ArH),

7.11–7.04 (m, 8H, ArH), 3.98 (t, J = 6.4 Hz, 4H, -OCH₂-),

1.81 (quin, J = 7.0 Hz, 4H, -OCCH₂-), 1.49–1.26 (m, 44H

(-CH₂-)₁₁× 2), 0.879 (t, J = 6.8 Hz, 6H, -CH₃).

4,5-Bis(m-hexadecyloxyphenylthio)phthalonitrile

(5i). SiO₂, CH₂Cl₂:n-hexane = 5:2, R_f= 0.70. Yield

73.9%, mp 58.3°C (mp₁), 70.2°C (mp₂) (this compound

1

showed double melting behavior). H NMR (400 MHz,

CDCl₃, TMS): d, ppm 7.41 (t, J = 8.2 Hz, 2H, ArH),

7.11–7.03 (m, 8H, ArH), 3.98 (t, J = 6.4 Hz, 4H, -OCH₂-),

1.81 (quin, J = 7.0 Hz, -OCCH₂-), 1.47 (quin, J = 7.2 Hz,

-OCCCH₂-), 1.38–1.26 (m, 48H, -(CH₂)₁₂-,), 0.878 (t, J =

6.8 Hz, 6H, -CH₃).

Octakis(m-ethoxyphenylthio)phthalocyaninato

copper(II) (1b). A three necked ﬂask was charged with

anhydrous CuCl₂(15.5 mg, 0.115 mmol), 4,5-bis(3-

ethoxyphenylthio)phthalonitrile (94.1 mg, 0.218 mmol)

and 1-hexanol (5 mL). To the reaction mixture 5 drops of

DBU was added and reﬂuxed for 1.5 h. It was cooled to rt

and poured into methanol to precipitate. The precipitates

were collected by ﬁltration and washed with methanol,

ethanol and ethyl acetate successively. The precipitates

were puriﬁed by Soxhlet extraction (toluene) two times.

The obtained toluene solution was concentrated in vacuo

and the residue was reprecipitated from acetone to obtain

green solid (43.1 mg).

The homologs 1c, 1h and 1i were also synthesized and

puriﬁed by the same procedure for 1b.

Octakis(m-hexyloxyphenylthio)phthalocyaninato

copper(II) (1d). A three necked ﬂask was charged

with anhydrous CuCl₂(9.2 mg, 0.068 mmol), 4,5-bis

(3-hexyloxyphenylthio)phthalonitrile (5d: 48.2 mg,

1

chromatography, yields, melting points and H NMR

data were described below for these homologs.

4,5-Bis(m-butoxyphenylthio)phthalonitrile

(5c).

SiO₂, CH₂Cl₂:n-hexane = 4:1, R_f= 0.30. Yield 68.9%, mp

96.1°C. ¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.41

(t, J = 7.4 Hz, 2H, ArH), 7.11–7.04 (m, 8H, ArH), 3.99

(t, J = 6.6 Hz, 4H, -OCH₂-), 1.80 (quin, J = 7.0 Hz, 4H,

-OCCH₂-), 1.51 (sext, J = 7.5 Hz, 4H, -OCCCH₂-), 0.993

(t, J = 7.4 Hz, 6H, -CH₃).

4,5-Bis(m-hexyloxyphenylthio)phthalonitrile (5d).

SiO₂, CH₂Cl₂:n-hexane = 4:1, R_f= 0.48. Yield 86.0%, mp

64.1°C. ¹H NMR (400 MHz, CDCl₃, TMS): d, ppm 7.41

(t, J = 7.9 Hz, 2H, ArH), 7.11–7.03 (m, 8H, ArH), 3.98

(t, J = 6.4 Hz, 4H, -OCH₂-), 1.81 (quin, J = 7.0 Hz, 4H,

-OCCH₂-), 1.49–1.33 (m, 12H, (-CH₂-)₃× 2), 0.914 (t,

J = 7.0 Hz, 6H, -CH₃).

J. Porphyrins Phthalocyanines 2017; 21: 9–20

10

Y. CHINO ET AL.

0.0885 mmol) and 1-hexanol (5 mL). To the reaction

mixture 5 drops of DBU was added and it was reﬂuxed

with stirring for 1.5 h. It was cooled to rt and poured into

methanol to precipitate. The precipitates were collected

by ﬁltration and washed with methanol, ethanol and

ethyl acetate successively. The residue was dissolved in

chloroform and the solution was concentrated in vacuo.

Subsequently, the crude product was puriﬁed by column

chromatography (SiO₂, CHCl₃, Rf = 1.0) to obtain green

solid (27.6 mg).

decyloxy group. Due to the low polarity of substituent R

in this study, Compound 4f could not be separated from

the reaction mixture.

Route (b) in Scheme 1 was followed [30]. Firstly,

the OH group in 3-iodophenol was substituted by long

alkoxy group using Williamson reaction to obtain

derivatives 2Bb~2Bi. Subsequently, these iodobenzene

derivatives 2Bb~2Bi were successfully converted into

benzenethiol derivatives 4b~4i in good yields (average

total yield: 62.8%).

The homologs 1e~1g were also synthesized and

puriﬁed by the same procedure for 1d. Table 1 lists the

yields, MALDI-TOF-MASS and elemental analysis data

of all the homologs 1b~1i. The UV-vis spectral data were

summarized in Table 2.

Derivative 4i was also successfully synthesized by

using another method [31] (Route (c) in Scheme 1).

Firstly, commercially available 3-hydroxybenzenethiol

was converted into corresponding disulﬁde derivative 2C

in the presence of HBr aq. sol. and DMSO. Subsequently,

the OH groups in this disulﬁde derivative 2C were

substituted by long alkoxy groups using Williamson

reaction to obtain disulﬁde derivative 3Ci. Following the

method used by authors in Ref. 32, derivative 3Ci was

converted into corresponding benzenethiol derivative

4i. This method also successfully provided the key

benzenethiol derivative 4i in moderate yield (total yield:

20.1%).

Decomposition temperatures of 1b~1i

Decomposition temperatures (T_d) obtained from TGA

are listed below.

1b. T_d> 400°C, 1c. T_d= 389°C, 1d. T_d= 397°C, 1e.

T_d= 359°C, 1f. T_d= 386°C, 1g. T_d= 399°C, 1h. T_d=

371°C, 1i. T_d= 360°C.

Thus, the methods of Routes (b) and (c) in Scheme

1 successfully provided the long alkoxy-substituted

benzenethiol derivatives 4b~4i.

RESULTS AND DISCUSSION

As shown in Scheme 2, the target phthalocyanine

derivatives (m-C_nOPhS)₈PcCu (1a~1i) were synthesized

using the method used by authors in Ref. 33. Firstly,

each of the long alkoxy-substituted benzenethiol

derivatives 4a~4i was reacted with 4,5-dichlorophthalo-

nitrile to obtain the phthalonitrile derivatives 5a~5i.

These phenylthio-substituted phthalonitriles 5a~5i were

tetracyclized to afford the target phenylthio-substituted

phthalocyanines, (m-C_nOPhS)₈PcCu (1a~1i), in relati-

vely good yields (average yield: 59%). Each of the

phthalocyanines could be satisfactorily identiﬁed by the

MALDI-TOF MASS, elemental analysis and UV-vis

spectrum (Tables 1 and 2).

Synthesis

Phenylthio substituted phthalocyanine derivatives

(PhS)₈PcM (M = H₂, metal) reported up to date were

prepared from commercially available benzenethiol

derivatives as the starting reagents [10–20]. However,

each of these benzenethiol derivatives does not have

long alkyl chains. Therefore, at ﬁrst we have developed

the synthetic route for the long alkoxy chain-substituted

benzenethiols 4b~4i in this study. Although many

synthetic methods for benzenethiol derivatives have been

reported so far [34–39], we have tried in this study the

following three relatively simple methods (Routes (a), (b)

and (c) in Scheme 1) for the long alkoxy chain-substituted

benzenethiol precursors 4b–4i.

Phase transition behavior

Route(a)inScheme1wasfollowed[26, 27].The starting

material, 3-hydroxybenzenethiol, was commercially

available. The thiol group in 3-hydroxybenzenethiol

was protected with trityl group to obtain derivative 2A.

Subsequently, the OH group in the phenol derivative 2A

was substituted by an alkoxy group using Williamson

reaction to obtain derivative 3Af. The trityl group in 3Af

was deprotected by triethylsilane in acidic condition.

Although the reaction proceeded, it was not possible

to separate the target compound 4f and the by-product

containing trityl group. It is attributable to the nonpolarity

of both the target compound and the by-product having

non-polar decyl groups. In Refs. 26 and 27, the target

benzenethiol derivative can be separated from reaction

mixture since substituent R is higher polarity group than

Table 3 summarizes phase transition behavior of all

the phenylthio-substituted PcCu complexes: the shortest-

alkoxy-substituted derivative (m-C₁OPhS)₈PcCu (1a)

synthesized in our previous work, and the other longer-

alkoxy-substituted derivatives, (m-C_nOPhS)₈PcCu (n =

2~16; 1b~1i), synthesized in this work.

In Fig. 2, the phase transition temperatures of all the

derivatives (m-C_nOPhS)₈PcCu (n = 1~16: 1a~1i) were

plotted against the alkyl chain length (n). As can be seen

this ﬁgure, each of the lines for the clearing points (),

the highest melting points (·), and the liquid crystal–

liquid crystal transition points () is very smoothly

connected. However, there is only a gap between n = 2

and 4 for the melting points. It may correspond to the

difference of mesomorphism driving forces between the

J. Porphyrins Phthalocyanines 2017; 21: 10–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

11

hexagonal ordered columnar (Col_ho) phases for 1a–1b

(n = 1, 2) and the rectangular ordered columnar (Col_ro

(P2m)) phases for 1c~1i (n = 4~16). Furthermore, each of

the derivatives 1f~1i (n = 10~16) shows two rectangular

ordered columnar phases of Col_ro1(P2m) and Col_ro2(P2m).

Interestingly, the Col_hophases appear only for the

extremely short alkoxy-substituted derivatives 1a–1b

(n = 1, 2), so that these discogens can be considered

as ﬂying-seed-like liquid crystals induced by thermal

ﬂuctuation of the bulky peripheral substituents [20–25].

On the other hand, the Col_ro(P2m) phase(s) appear only

for the longer alkoxy-substituted derivatives 1c~1i

(n = 4~16), so that these discogens can be considered

as conventional liquid crystals induced by melting of

the peripheral long alkoxy chains. To the best of our

knowledge, this is the ﬁrst example of changing from

ﬂying-seed-like liquid crystals to long alkyl chain

type of liquid crystals in a series of liquid crystalline

homologs.

Polarizing optical microscopic observation

Figure 3 shows the polarizing optical photomicro-

graphs of liquid crystalline phases in the representative

derivatives, 1b (n = 2), 1f (n = 10) and 1i (n = 16).

Both (a) and (b) are the photomicrographs of the liquid

crystalline phase in the shortest alkoxy-substituted

derivative (m-C₂OPhS)₈PcCu (1b) at 220°C. As can be

Fig. 2. Phase transition temperature vs. the number of carbon

atom in the alkoxy chains for (m-C_nOPhS)₈PcCu (1a–1i).

: clearing point, : melting point, : crystal–crystal phase

·

.

transition, and : mesophase–mesophase transition

Fig. 3. Photomicrographs of (a) and (b): Col_hoof (m-C₂OPhS)₈PcCu (1b) at 220°C; (c) Col_ro2(P2m) of (m-C₁₀OPhS)₈PcCu (1f) at

115°C; (d) Col_ro1(P2m) of (m-C₁₀OPhS)₈PcCu (1f) at 90°C; (e) sheared sample of the photo (d) of 1f at 90°C; (f) Col_ro1(P2m) of

(m-C₁₆OPhS)₈PcCu (1i) at 100°C; (g) sheared sample of the photo (f) of 1i at 100°C

J. Porphyrins Phthalocyanines 2017; 21: 11–20

12

Y. CHINO ET AL.

Table 4. X-ray data of 1a~1i

Compound (mesophase)

Lattice constants/Å

Spacing/ Å

Miller indices (h k l)

Observed

Calculated

1a*: (m-C₁OPhS)₈PcCu

Col_hoat 300°C

a = 20.9

h = 6.82

18.1

13.6

18.2

13.6

10.5

9.05

6.82

6.03

3.95

(1 0 0)

(0 0 1)^2h

Z = 0.95 for r = 1.1

10.1

(1 1 0)

9.16

(2 0 0)

6.82

(0 0 1)^h

(3 0 0) + #1

(4 1 0)

ca. 5.9

3.98

1b: (m-C₂OPhS)₈PcCu

Col_hoat 220°C

a = 22.0

h = 7.12

19.0

14.3

19.0

14.4

11.0

7.19

6.34

—

(1 0 0)

(0 0 1)^2h

Z = 1.0 for r = 1.1

10.9

(1 1 0)

7.12

(2 1 0) + (0 0 1)^h

(3 0 0)

6.23

ca. 5.2

4.00

#1

4.15

(4 1 0)

1c: (m-C₄OPhS)₈PcCu

Col_ro2(P2m) at 199°C

a = 22.7

b = 21.7

22.7

10.8

7.17

5.26

4.88

4.18

3.71

22.7

10.8

7.17

5.27

4.89

4.19

3.73

(1 0 0)

(0 2 0)

h = 7.17

(0 0 1)^h

Z = 1.1 for r = 1.0

(1 4 0)

(2 4 0) + #1

(5 2 0)

(6 1 0)

1d: (m-C₆OPhS)₈PcCu

Col_ro2(P2m) at 148°C

a = 36.8

b = 26.6

26.6

18.4

10.7

8.61

7.92

5.82

5.02

4.58

4.06

3.60

26.6

18.4

10.8

8.63

8.00

5.85

5.04

4.60

4.08

3.60

(0 1 0)

(2 0 0)

(2 2 0)

(1 3 0)

(2 3 0)

(3 4 0)

(6 3 0)

(8 0 0) + #2

(8 3 0)

(0 0 1)^h

h = 3.60

Z = 1.0 for r = 1.1

1e: (m-C₈OPhS)₈PcCu

Col_ro2(P2m) at 115°C

a = 35.0

b = 27.5

35.0

21.6

15.9

10.8

35.0

21.6

14.8

10.7

(1 0 0)

(1 1 0)

(2 1 0)

(3 1 0)

h = 3.99

Z = 1.0 for r = 1.1

(Continued)

J. Porphyrins Phthalocyanines 2017; 21: 12–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

13

Table 4. (Continued)

Compound (mesophase)

Lattice constants/Å

Spacing/ Å

Miller indices (h k l)

Observed

Calculated

7.06

6.58

5.14

4.69

3.99

7.00

6.41

5.25

4.70

3.99

(5 0 0)

(2 4 0)

(2 5 0) + #2

(7 2 0) + #2

(0 0 1)^h

1f: (m-C₁₀OPhS)₈PcCu

Col_ro1(P2m) at 80°C

a = 36.6

b = 27.2

36.6

21.8

13.6

10.9

7.07

4.98

4.57

4.01

37.0

22.1

11.1

7.15

5.05

4.60

4.06

(1 0 0)

21.8

13.7

10.7

(1 1 0)

h = 4.01

(0 2 0)

Z = 0.98 for r = 1.1

(2 2 0)

6.93

(5 1 0)

5.01

4.61

4.01

(5 4 0) + #2

(8 0 0) + #2

(0 0 1)^h

Col_ro2(P2m) at 115°C

a = 37.0

b = 27.6

37.0

(1 0 0)

22.1

10.6

(1 1 0)

h = 4.06

(2 2 0)

Z = 1.0 for r = 1.1

7.06

(5 1 0)

5.08

4.61

4.06

(5 4 0) + #2

(0 6 0) + #2

(0 0 1)^h

1g: (m-C₁₂OPhS)₈PcCu

Col_ro2(P2m) at 100°C

a = 39.5

b = 21.3

39.5

21.3

10.7

7.90

7.00

5.09

—

(1 0 0)

(0 1 0)

(0 2 0)

(5 0 0)

(1 3 0)

(0 0 1)^h

#2

21.3

10.7

h = 5.09

Z = 0.97 for r = 1.1

8.02

6.98

5.09

4.63

Col_ro1(P2m) at 90°C

a = 43.1

b = 21.6

43.1

21.6

13.7

10.8

7.11

4.96

—

(1 0 0)

(0 1 0)

(3 0 0)

(4 0 0)

(1 3 0)

(0 0 1)^h

#2

21.6

13.7

10.8

h = 4.96

Z = 1.1 for r = 1.1

7.04

4.96

4.62

1h: (m-C₁₄OPhS)₈PcCu

Col_ro2(P2m) at 105°C

a = 43.7

b = 21.5

43.7

21.5

14.6

10.7

(1 0 0)

(0 1 0)

(3 0 0)

(0 2 0)

21.5

14.4

10.6

h = 5.08

Z = 1.0 for r = 1.1

(Continued)

J. Porphyrins Phthalocyanines 2017; 21: 13–20

14

Y. CHINO ET AL.

Table 4. (Continued)

Compound (mesophase)

Lattice constants/Å

Spacing/ Å

Miller indices (h k l)

Observed

7.14

Calculated

7.15

(0 3 0)

(0 0 1)^h

#2

5.08

—

ca. 4.6

Col_ro1(P2m) at 85°C

a = 50.1

b = 22.6

50.1

22.6

50.1

22.6

13.4

11.0

7.16

—

(1 0 0)

(0 1 0)

(3 1 0)

(4 1 0)

(7 0 0)

#2

h = 4.59

14.3

Z = 1.1 for r = 1.1

10.7

7.09

ca. 4.9

4.59

(0 0 1)^h

1i: (m-C₁₆OPhS)₈PcCu

Col_ro1(P2m) at 100°C

a = 49.9

b = 28.6

49.9

24.8

49.9

24.8

16.6

10.8

7.07

—

(1 0 0)

(1 1 0)

(3 0 0)

(3 2 0)

(1 4 0)

#2

h = 4.07

17.0

Z = 1.0 for r = 1.0

10.7

7.07

ca. 5.1

ca. 4.6

4.07

—

#2

(0 0 1)^h

4.07

#1, #2 = broad halos due to the thermal ﬂuctuation of the phenylthio groups and the molten alkyl

chains, respectably. h = stacking distance. r = assumed density (g/cm³). * [20].

seen from these photos, photo (a) shows a focal conic

texture typical of liquid crystalline phases and photo

(b) shows a dendritic texture typical of a hexagonal

columnar (Col_h) phase. Therefore, this liquid crystalline

phase of 1b could be identiﬁed as a Col_hphase. Photo

(c) is a Col_ro2(P2m) phase in the moderately long alkyl-

substituted derivative (m-C₁₀OPhS)₈PcCu (1f) at 115°C.

Both (d) and (e) are a Col_ro1(P2m) phase in the same

derivative 1f at 90°C. As can be seen from these photos,

both Col_ro1,2phases did not give any typical textures

of mesophases. However, when the phase in photo (d)

was pressed and sheared, it showed both stickiness

and birefringence as shown in photo (e). Therefore,

the Col_ro1(P2m) phase in 1f could be identiﬁed as a

liquid crystalline phase. Photo (f) shows a Col_ro1(P2m)

phase in the longest alkoxy-substituted derivative

(m-C₁₆OPhS)₈PcCu (1i) at 100°C. This photo exhibits

a focal conic texture typical of liquid crystalline phases.

In addition, when this sample was pressed and sheared,

it showed both stickiness and birefringence as shown in

photo (g). Therefore, this phase could be also identiﬁed

as a liquid crystalline phase.

Temperature-dependent small angle X-ray

diffraction (TD-SAXS) measurements

Table 4 summarizes temperature-dependent small

angle X-ray diffraction (TD-SAXS) data of the

liquid crystalline phases in (m-C_nOPhS)₈PcCu (1a~1i).

Figures 4, 5 and 6 show the representative SAXS patterns

of (m-C₂OPhS)₈PcCu (1b), (m-C₁₀OPhS)₈PcCu (1f) and

(m-C₁₆OPhS)₈PcCu (1i), respectively. In these ﬁgures,

the enlarged diffractgrams are shown as the insets. These

SAXS patterns were measured for the samples obtained

by cooling from isotropic liquid.

The SAXS pattern of (m-C₂OPhS)₈PcCu (1b) at

220°C is shown in Fig. 4. As can be seen from this

ﬁgure, a very broad halo (#1) due to thermal ﬂuctuation

of phenylthio groups was observed in 2Θ = 13~23°. This

broad halo #1 was also observed for the previous ﬂying-

seed-like liquid crystalline derivative, (m-C₁OPhS)₈PcCu

(1a) [20]. The d-spacings in the low angle region are in a

ratio of 1:1/√3:1/√7:1/3, which is typical of a Col_hphase.

Therefore, the mesophase could be identiﬁed as a Col_h

phase. This identiﬁcation is consistent with the dendritic

J. Porphyrins Phthalocyanines 2017; 21: 14–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

15

Fig. 4. XRD pattern of (m-C₂OPhS)₈PcCu (1b) at 220°C (on cooling from I.L). #1 = broad halo due to the thermal ﬂuctuation of

the phenylthio groups

Fig. 5. XRD pattern of (m-C₁₀OPhS)₈PcCu (1f) at 115°C. #2 = broad halo due to the molten alkyl chains

texture typical of a Col_hmesophase mentioned above. In

addition, two peaks at around 2Θ = 6° and 13° could be

assigned to the interdimer stacking d₀₀₁(2h = 14.3 Å) and

the intermonomer stacking d₀₀₁(h = 7.12 Å), respectively.

This means that an equilibrium between the dimers and

monomers exists in the Col_homesophase as the same case

as the [m,p-(C_nO)₂PhO]₈PcCu derivatives reported in

2001 [7]. From the Z value calculation [40], the Z value

of this Col_homesophase in 1b could be obtained as Z =

1.0 assuming the intermonomer stacking distance as h =

7.12Å and the density of the mesophase as r = 1.0 g.cm^-3.

Although the intracolumnar stacking distance h (7.12 Å)

is much larger than that of conventional Col_hophases.

However,thevalueZ=1.0isconsistentwiththetheoretical

J. Porphyrins Phthalocyanines 2017; 21: 15–20

16

Y. CHINO ET AL.

Fig. 6. XRD pattern of (m-C₁₆OPhS)₈PcCu (1i) at 100°C (on cooling from I.L). #2 = broad halo due to the molten alkyl chains

value (Z = 1.0) for a Col_homesophase. Moreover, the large

stacking distance h = 7.12 Å is comparable to that of

ﬂying-seed-like liquid crystals reported in our previous

works [20, 24]. Thus, the present derivative 1b could

be classiﬁed as a ﬂying-seed-like liquid crystal similar

to the previously reported derivative 1a. In our previous

work, this liquid crystalline phase of 1a was identiﬁed as

a Col_ro(P2m) phase [20]. However, the d spacings of 1a

(Col_ro(P2m)) phase (s), whereas each of the previous

longer alkoxy-substituted phenoxy derivatives (m-

C_nOPhO)₈PcCu(n = 10~20) showed only a hexagonal

columnar (Col_ho) phase [8, 9].

Columnar stacking structures of (m-C_nOPhO)₈PcCu

(n = 10–20) and (m-C_nOPhS)₈PcCu (n = 1–16)

are also in a ratio of 1:1/√3:1/√7:1/3, the same as that of

The different mesophase appearance mentioned above

may be attributed to difference of interaction among

the Pc cores having steric hindrance of the peripheral

substituents (PhO and PhS).

.

1b. From the Z value calculation, the result (Z = 0.95 .

1.0) is consistent with a Col_hophase. Moreover, the

equilibrium between the dimers and monomers in the

Col_homesophase could be also observed as the same case

as the (m-C₂OPhS)₈PcCu (1b) homolog. Therefore, the

liquid crystalline phase of 1a could be also identiﬁed as

Col_hophase, so that we correct the identiﬁcation of this

mesophase from Col_ro(P2m) to Col_hoin this study.

Figure 5 shows a SAXS pattern of the moderately

long alkoxy-substituted derivative (m-C₁₀OPhS)₈PcCu

(1f) at 115°C. As can be seen from this ﬁgure, a broad

halo (#2) due to the molten long alkyl chains was

observed. From the reciprocal lattice calculation [40],

the liquid crystalline phase was identiﬁed as Col_ro2

(P2m) (a = 37.0 Å, b = 27.6 Å, h = 4.06 Å). Figure 6

shows the SAXS pattern of the longest alkoxy-

substituted derivative (m-C₁₆OPhS)₈PcCu (1i) at 100°C.

The liquid crystalline phase was also identiﬁed as

Col_ro1(P2m) (a = 49.9 Å, b = 28.6 Å, h = 4.07 Å). It is

very interesting that each of the present longer alkoxy-

substituted phenylthio derivatives (m-C_nOPhS)₈PcCu

It is well-known that stronger interaction between cores

is required to form a rectangular columnar (Col_r) phase

in comparison with a hexagonal columnar (Col_h) phase

[41–43]. As schematically shown in Fig. 7, covalent bond

radius of sulfur atom (1.04 Å) is larger than that of oxygen

atom (0.66 Å). Hence, C–S bond length (1.81 Å) is longer

than C–O bond length (1.43 Å) [44]. Accordingly, the

interaction between Pc cores in the phenoxy-substituted

derivatives (m-C_nOPhO)₈PcCu (n = 10–20) is weakened

by bigger steric hindrance of the phenoxy groups closer

to the Pc core. As the result, the phenoxy-substituted

derivatives (m-C_nOPhO)₈PcCu (n = 10–20) may form the

hexagonal columnar phase (Col_h). On the other hand, the

interaction between Pc cores in the phenylthio-substituted

derivatives (m-C_nOPhS)₈PcCu (n = 4–16) is strengthened

by smaller steric hindrance of phenylthio group farther

from the Pc core. In this case, an additional coordination

bonds may be formed between copper atoms and nitrogen

atoms between the upper and lower Pc cores, as illustrated

(n

= 4~16) showed only rectangular columnar

J. Porphyrins Phthalocyanines 2017; 21: 16–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

17

Fig. 7. Columnar stacking structures of (m-C_nOPhO)₈PcCu (n = 10–20) and (m-C_nOPhS)₈PcCu (n = 4–16)

in Fig. 7 (dotted lines). Thus, the phenylthio-substituted

derivatives (m-C_nOPhS)₈PcCu (n = 4–16) may form the

rectangular columnar (Col_r) phase.

the phenylthio-substituted derivative (m-C₁₀OPhS)₈PcCu

(1f) red-shifts by 35.7 nm into near infrared region

compared with the phenoxy-substituted derivative

(m-C₁₀OPhO)₈PcCu. This result is compatible with those

of the phenylthio-substituted phthalocyanes reported so far

[16–20].

UV-vis absorption spectra

Figure 8 shows the UV-vis absorption spectra of

(m-C₁₀OPhO)₈PcCu (upper) and (m-C₁₀OPhS)₈PcCu (1f)

(lower) in THF solution. Table 5 lists their spectral data.

As can be seen from these ﬁgure and table, the Q-band of

Moreover, we could estimate the optical band gaps

of (m-C₁₀OPhO)₈PcCu and (m-C₁₀OPhS)₈PcCu (1f)

from absorption edge of the Q-bands to be 1.79 eV and

1.70 eV, respectively. Hence, the phenylthio-substituted

J. Porphyrins Phthalocyanines 2017; 21: 17–20

18

Y. CHINO ET AL.

Fig. 8. UV-vis absorption spectra of (m-C₁₀OPhO)₈PcCu (upper) and (m-C₁₀OPhS)₈PcCu (1f) (lower) in THF solution

Table 5. UV-vis spectral data of (m-C₁₀OPhO)₈PcCu and (m-C₁₀OPhS)₈PcCu in THF solution

Compound

Concentration

(X10^-6mol L^-1)

l_abs/nm (loge)

l_edge/nm E_gap*/eV

Soret band

Q-band

Q_0–1-band

Q_0–0-band

(m-C₁₀OPhO)₈PcCu

2.27

2.29

351.9 (4.93) 608.3 (4.64)

353.3 (4.90) 635.7 (4.69)

675.9 (5.43)

711.6 (5.44)

692.8

731.1

1.79

1.70

(m-C₁₀OPhS)₈PcCu (1f)

* E_gapwas estimated from the absorption edge of Q-band.

J. Porphyrins Phthalocyanines 2017; 21: 18–20

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES, 53

19

derivative gave a narrower band gap by ca. 0.1 eV in

comparison with the phenoxy-substituted derivative.

10. Kandaz M, Yılmaz İ and Bekarog˘lu Ö. Polyhedron

2000; 19: 115–121.

11. Balakireva OV, Maizlish VE and Shaposhnikov GP.

Russ. J. Gen. Chem. 2003; 73: 292–296.

12. Kobayashi N, Ogata H, Nonaka N and Luk’yanets

EA. Chem. Eur. J. 2003; 9: 5123–5134.

CONCLUSION

In this study, we have successfully synthesized

novel phenylthio-substituted phthalocyanine derivatives

(m-C_nOPhS)₈PcCu(1b~1i)torevealtheirmesomorphism.

We found that the shortest alkoxy-substituted derivatives,

(m-C₁OPhS)₈PcCu (1a) and (m-C₂OPhS)₈PCu (1b) could

be classiﬁed as ﬂying-seed-like liquid crystals. On the

otherhand, theotherlongeralkoxy-substitutedderivatives

(m-C_nOPhS)₈PcCu: n = 4~16 (1c~1i) could be classiﬁed

as conventional long alkyl-chain-melting liquid crystals.

It is very interesting that each of the present longer alkoxy-

substituted phenylthio derivatives (m-C_nOPhS)₈PcCu

(n = 4~16) showed only rectangular columnar (Col_ro-

(P2m)) phase(s), whereas each of the previous longer

alkoxy-substituted phenoxy derivatives (m-C_nOPhO)₈PcCu

(n = 10~20) showed only a hexagonal columnar (Col_ho)

phase. The different mesophase appearance may be

originated from the difference of interaction among the Pc

cores having steric hindrance of the peripheral substituents

(PhO and PhS). The Q-band of the phenylthio-substituted

derivative (m-C₁₀OPhS)₈PcCu (1f) red-shifts by 35.7 nm

into near infrared region compared with the phenoxy-

substituted derivative (m-C₁₀OPhO)₈PcCu. Thus, in

this study, we successfully synthesized a novel series

of liquid crystalline (m-C_nOPhS)₈PcCu (n = 1~16)

derivatives showing the Q-bands in near infrared region.

We intend to measure the charge carrier mobilities in the

near future.

13. Lu G, Bai M, Li R, Zhang X, Ma C, Lo P-C, Ng DKP

and Jiang J. Eur. J. Inorg. Chem. 2006; 3703–3709.

14. Arican D, Arici M, Ug˘ur AL, Erdog˘mus A and Koca

A. Electrochimica Acta 2013; 106: 541–555.

15. Mayukh M, Lu C-W, Hernandez E and McGrath

DV. Chem. Eur. J. 2011; 17: 8427–8478.

16. Polaske NW, Lin H-C, Tang A, Mayukh M,

Oquendo LE, Green J, Ratcliff EL, Armstrong NR,

Saavedra SS and McGrath DV. Langmuir 2011; 27:

14900–14909.

17. Yu L, Shi W, Lin L, Guo Y, Li R and Peng T. Dyes

Pigm. 2015; 114: 231–238.

18. Shi W, Peng B, Guo Y, Lin L, Peng T and Li R. J.

Photochem. Photobiol., A 2016; 321: 248–256.

19. Zimcik P, Malkova A, Hruba L, Miletin M and

Novakova V. Dyes Pigm. 2017; 136: 715–723.

20. Ishikawa A, Ohta K and Yasutake M. J. Porphyrins

Phthalocyanines 2015; 19: 639–650.

21. Ohta K, Shibuya T and Ando M. J. Mater. Chem.

2006; 16: 3635–3639.

22. Takagi Y, Ohta K, Shimosugi S, Fujii T and Itoh E.

J. Mater. Chem. 2012; 22: 14418–14425.

23. Hachisuga A, Yoshioka M, Ohta M and Itaya T. J.

Mater. Chem. C 2013; 1: 5315–5321.

24. Yoshioka M, Ohta K and Yasutake M. RSC Adv.

2015; 5: 13828–13839.

25. Watarai A, Ohta K and Yasutake M. J. Porphyrins

Phthalocyanines 2016; 20: 822–832.

26. Barluenga S, Dakas P-Y, Ferandin Y, Meijer L and

Winssinger N. Angew. Chem. Int. Ed. 2006; 45:

3951–3954.

REFERENCES

1. Chandrasekhar S, Sadashira BK and Suresh KA.

Pramana 1977; 9: 471–480.

2. Cammidge AN and Bushby RJ. Handbook of Liquid

Crystals, Vol. 2B, Wiley-VCH: 1998; Chap. 7,

pp. 693–743.

3. Sergeyev S, Pisula W and Geerts YH. Chem. Soc.

Rev. 2007; 36: 1902–1929.

4. Ban K, Nishizawa K, Ohta K and Shirai H. J. Mater.

Chem. 2000; 10: 1083–1090.

5. van de Craats AM, Shouten PG and Warman JM.

Ekisho, 1998; Vol. 2, no. 1.

6. Warman JM, Kroeze JE, Schouten PG and van de

Craats AM. J. Porphyrins Phthalocyanines 2003; 7:

342–350.

27. Patent PCT/US2006/041501.

28. Hwang JY, Arnold LA, Zhu F, Kosinski A, J. Man-

gano T, Setola V, Roth BL and Guy RK. J. Med.

Chem. 2009; 52: 3892–3901.

29. Wakioka M, Ikegami M and Ozawa F. Macromol-

ecules 2010; 43: 6980–6985.

30. Jiang Y, Qin Y, Xie S, Zhang X, Dong J and Ma D.

Org. Lett. 2009; 11: 5250–5253.

31. Natarajan P, Sharma H, Kaur M and Sharma P. Tet-

rahedron. Lett. 2015; 56: 5578–5582.

32. Patel SK and Long TE. Tetrahedron. Lett. 2009; 50:

5067–5070.

33. Wöhrle D, Eskes M, Shigehara K and Yamada A.

Synthesis 1993; 194–196.

34. Kamiyama T, Enomoto S and Inoue M. Chem.

Pharm. Bull. 1985; 33: 5184–5189.

35. Newman MS and Karnes HA. J. Org. Chem. 1996;

31: 3980–3984.

7. Hatsusaka K, Ohta K, Yamamoto I and Shirai H.

J. Mater. Chem. 2001; 11: 423–433.

8. Ichihara M, Suzuki A, Hatsusaka K and Ohta K.

J. Porphyrins Phthalocyanines 2007; 11: 503–512.

9. Sato H, Igarashi K, Yama Y, Ichihara M, Itoh E and

Ohta K. J. Porphyrins Phthalocyanines 2012; 16:

1148–1158.

36. Itoh T and Mase T. Org. Lett. 2004; 6: 4587–4590.

J. Porphyrins Phthalocyanines 2017; 21: 19–20

20

Y. CHINO ET AL.

37. Itoh T and Mase T. J. Org. Chem. 2006; 71:

2203–2206.

Society, Sigma Shuppan: Tokyo, 2007; Chap. 2-(3),

pp. 11–21, ISBN-13:978-4915666490.

38. Mazzio KA, Okamoto K, Li Z, Gutmann S, Strein

E, Glinger DS, Sclaf R and Luscombe CK. Chem.

Commun. 2013; 49: 1321–1323.

39. Heine NB and Studer A. Macromol. Rapid.

Commun. 2016; 37: 1494–1498.

40. (a) Ohta K. Dimensionality and Hierarchy of Liquid

Crystalline Phases: X-ray Structural Analysis of the

Dimensional Assemblies, Shinshu University Insti-

tutional Repository, submitted on 11 May, 2013;

http://hdl.handle.net/10091/17016. (b) Ohta K. In

Identiﬁcation of discotic mesophases by X-ray

structure analysis, Introduction to Experiments

in Liquid Crystal Science (Ekisho Kagaku Jikken

Nyumon [in Japanese]), Japanese Liquid Crystal

41. Laschat S, Baro A, Steinke N, Giesselmann F,

Hägele C, Scalia G, Judele R, Kapatsina E, Sauer S,

Schreivogel A and Tosoni M. Angew. Chem. Int. Ed.

2007; 46: 4832–4887.

42. Zheng H, Lai CK and Swager TM. Chem. Mater.

1995; 7: 2067–2077.

43. Morale F, Date RW, Gullion D, Bruce DW, Finn

RL, Wilson C, Blake AJ, Schröder M and Donnio

B. Chem. Eur. J. 2003; 9: 2484–2501.

44. Atkins PW and de Paula J. Physical Chemistry, 8th

edition, 2006.

45. Watarai A, Ohta K and Yasutake M. J. Porphyrins

Phthalocyanines 2016; 20: 1444–1456.

J. Porphyrins Phthalocyanines 2017; 21: 20–20

Article Doi

Discotic liquid crystals of transition metal complexes, 53?: Synthesis and mesomorphism of phthalocyanines substituted by m -alkoxyphenylthio groups

DOI: 10.1142/S1088424617500389

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Full text of DOI:10.1142/S1088424617500389

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