scholarly journals Discotic liquid crystals of transition metal complexes 51: Synthesis and mesomorphism of flat-pumpkin-shaped phthalocyanine-fullerene dyads

2014 ◽  
Vol 18 (10n11) ◽  
pp. 856-868 ◽  
Author(s):  
Miho Yoshioka ◽  
Kazuchika Ohta ◽  
Yohei Miwa ◽  
Shoichi Kutsumizu ◽  
Mikio Yasutake

We have synthesized a novel type of donor–acceptor liquid crystalline material, phthalocyanine-fullerene ( Pc - C 60) dyad, [m,p,m′-( C 14 O )3 PhO ]6 PcCu - C 60 (7), and the Pc precursors, [m,p,m′-( C 14 O )3 PhO ]6 PcCu - OFBA (6) and [m,p,m′-( C 14 O )3 PhO ]6 PcCu - OH (5), and established their mesomorphism by using a polarizing optical microscope, a differential scanning calorimeter and a small angle X-ray diffractometer. Very interestingly, their corresponding previous parent Pc derivative, [m,p,m′-( C 14 O )3 PhO ]8 PcCu (4), shows a very wide temperature region ca. 90°C of a bicontinuous Cub(Pn3m) mesophase, whereas the present children Pc precursors (5 and 6) and Pc- C 60 dyad 7 show not the Cub mesophase but a Colho mesophase. It is also noteworthy that the staking distance in the Colho mesophase of the Pc- C 60 dyad 7was a very big value of ca. 9.1 Å, which is the biggest in discotic liquid crystals to our best knowledge. It may be originated from the biggest excluded volume caused by thermal fluctuation of peripheral long alkoxy chains at m, m′-positions. The excluded volume caused by thermal fluctuation of the peripheral long chains is so big that the molecular shape of the Pc derivative 4 and the Pc- C 60 dyad 7 very resembles a flat pumpkin.

2007 ◽  
Vol 11 (07) ◽  
pp. 503-512 ◽  
Author(s):  
Masahiro Ichihara ◽  
Ayumi Suzuki ◽  
Kazuaki Hatsusaka ◽  
Kazuchika Ohta

In order to clarify the peripheral chain substitution position effect on columnar mesophase and stacking structures, we have synthesized three novel series of discotic liquid crystals (1-3) having octakis(phenoxy)phthalocyaninato copper(II) as a central core and one peripheral chain at the para position (1), meta position (2) or ortho position (3) of each phenoxy group, and three more novel series of discotic liquid crystals (4-6) having the same central core and two peripheral chains at para and meta positions (4), meta and meta positions (5) or ortho and meta positions (6) of each phenoxy group. Their columnar mesophase and stacking structures were investigated with a polarizing optical microscope, a differential scanning calorimeter and a temperature-dependent X-ray diffractometer. According to the results, their columnar mesophase and stacking structures strongly depended on the peripheral chain substitution positions and the number of peripheral chains. Derivatives 3 and 5 are viscous isotropic liquid at room temperature. Derivatives 1, 2, 4 and 6 exhibit various kinds of columnar mesophases: 1 Colhd; 2 Colhd and Colho; 4 Colhd, Colrd(P21/a), Coltet.d and Cub ( Pn [ three bar ] m ); 6 Colhd, Colrd(P21/a) and Colrd(X). Moreover, derivatives 1, 4 and 6 exhibit disordered columnar mesophases. However, derivative 2 only exhibits an ordered columnar mesophase and its X-ray diffraction pattern shows a sharp reflection corresponding to a very short intracolumnar stacking distance of 3.33 Å. Thus, we can drastically change the mesophase and stacking structures by the peripheral chain substitution positions and the number of peripheral chains at each phenoxy group. This is a new way of controlling mesomorphic structure.


2012 ◽  
Vol 16 (11) ◽  
pp. 1209-1216 ◽  
Author(s):  
Hiroyuki Sato ◽  
Yuya Sakagami ◽  
Eiji Itoh ◽  
Kazuchika Ohta

We synthesized a novel discotic liquid crystalline compound, octakis[3-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)phenoxy]phthalocyaninato copper(II) (abbreviated as [m- MeO(EtO)3PhO]8PcCu ), and established the mesomorphism by using a differential scanning calorimeter, a polarizing optical microscope, and temperature-dependent wide angle X-ray diffraction diffractometer. Very interestingly, this [m- MeO(EtO)3PhO]8PcCu complex showed a hexagonal ordered columnar (Colho) mesophase in the virgin sample, whereas it showed a rectangular ordered columnar (Colro(P21/a)) mesophase in the non-virgin sample. The Colho mesophase gave a dimer stacking distance at 9.26 Å, whereas the Colro mesophase gave a short monomer stacking distance at 3.45 Å. Furthermore, this novel Pc derivative is readily soluble in polar solvents such as acetone, ethanol and methanol. Using antagonist solubilities of the present hydrophilic [m- MeO(EtO)3PhO]8PcCu derivative in a polar solvent and the previous hydrophobic (C10O)16TzCu derivative in the non-polar solvent, a p-n junction layered thin films could be successfully prepared.


2021 ◽  
Vol 17 (3) ◽  
pp. 285-294
Author(s):  
Mohamad Azani Abd Khadir Jalani ◽  
Hendrik O. Lintang ◽  
Siew Ling Lee ◽  
Juan Matmin ◽  
Nur Fatiha Ghazalli ◽  
...  

Gold(I) pyrazolate complex ([Au3Pz3]C10TEG) has been widely studied due to its interesting liquid crystalline properties by exhibiting the discotic hexagonal columnar arrangement. Generally, the liquid crystalline properties of the gold complex were confirmed based on their differential scanning calorimetry thermogram and polarized optical microscopy (POM) images. However, there is still no in-depth study on the phase transition in liquid crystals of [Au3Pz3]C10TEG especially on its structural change at variable temperature. In this study, the resulting liquid crystalline properties of [Au3Pz3]C10TEG upon being heated and cooled was extensively demonstrated via variable-temperature POM (VT-POM) and small angle X-ray scattering (VT-SAXS). Based on the VT-POM images, it was indicated that [Au3Pz3]C10TEG displayed a fan-shaped texture for typical arrangements of discotic hexagonal columnar of liquid crystals. Moreover, VT-SAXS results was in good agreement with the VT-POM images as it showed that [Au3Pz3]C10TEG might consist of two types of stacking system, which are ordered and disordered hexagonal discotic arrangements. Likewise, VT-SAXS analysis also demonstrated that hexagonal columnar mesophase of [Au3Pz3]C10TEG could be recovered even after the heating and cooling for two cycles.


2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Monica Iliş ◽  
Viorel Cîrcu

Mesomorphic three-coordinate copper(I) complexes ([Cu(BTU)2X], where X = Cl or Br) based on a new N-benzoylthiourea (BTU) ligand with two decyloxy and one perfluorooctyl groups at its periphery were designed and prepared. The BTU ligand coordinates via the S atom in a neutral monodentate fashion as confirmed by IR and NMR spectroscopy data. The liquid crystalline behavior of these copper(I) complexes was investigated by a combination of polarized optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray diffraction analysis (XRD), while their thermal stability was studied by thermogravimetric analysis (TGA). These new copper(I) complexes have mesomorphic properties and exhibit a hexagonal columnar mesophase over a large temperature range, more than 100°C.


Soft Matter ◽  
2019 ◽  
Vol 15 (16) ◽  
pp. 3315-3322 ◽  
Author(s):  
Taiki Hoshino ◽  
Masanari Nakayama ◽  
So Fujinami ◽  
Tomotaka Nakatani ◽  
Yoshiki Kohmura ◽  
...  

The static structure and dynamics of liquid-crystalline colloidal dispersions of hydroxyapatite nanorods are studied using X-ray scattering techniques.


1997 ◽  
Vol 52 (12) ◽  
pp. 1539-1543 ◽  
Author(s):  
Esther Frackowiak ◽  
Günter Scherowsky

Abstract , 1997 1,3,5-Triphenylbenzenes, Chiral and Non-Chiral Substituents Aiming to design new discotic liquid crystals, chiral and non-chiral esters and ethers of hexa-and nonasubstituted 1,3,5-triphenylbenzenes were synthesized. The new compounds are crystalline or high viscous liquids. They do not form mesophases or columnar donor-acceptor-complexes with TNF, DNF or DBox-H. The chiral esters 5c and 5d. used as dopants, induce cholesteric phases in nematic discotics.


2013 ◽  
Vol 781-784 ◽  
pp. 403-406
Author(s):  
Mei Tian ◽  
Zhi Xin Xu ◽  
Li Gao ◽  
Dan Shu Yao ◽  
Xiao Zhi He ◽  
...  

A series of new main-chain liquid-crystal polymers (LCPs) were prepared from sebacoyl chloride (SD) and various amount of 4, 4-Dihydroxy-2, 2-dimethyl Benzalazine (DDBA) and isosorbide (ISO). The liquid crystal (LC) properties were investigated by polarized optical microscope (POM), differential scanning calorimetry (DSC) and X-ray diffraction measurements. P1 exhibited a typical nematic thread texture, which contains no ISO. P2-P7 are Sc* and N LCPs, which exhibited broken fan-shaped texture and droplet texture. The introduction of chiral units into the polymers led to a change of mesomorphase, as compared with P1.


Sign in / Sign up

Export Citation Format

Share Document