New phosphorescent platinum(ii) complexes: lamellar mesophase and mechanochromism

2016 ◽  
Vol 40 (12) ◽  
pp. 10371-10377 ◽  
Author(s):  
Hao Geng ◽  
Kaijun Luo ◽  
Guo Zou ◽  
Haifeng Wang ◽  
Hailiang Ni ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Photophysical Properties ◽  
Picolinic Acid ◽  
Auxiliary Ligand ◽  
Square Planar ◽  
Main Ligand

Several new square planar platinum(ii) complexes based on modified 2-phenylpyridine derivatives as the main ligand and picolinic acid as the auxiliary ligand were synthesized and their photophysical properties, and mechanochromic and liquid crystalline behavior were investigated.

scholarly journals Synthesis and Characterization of Photoluminescence Liquid Crystals Based on Flexible Chain-Bearing Pentafluorinated Bistolanes

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 603
Author(s):  
Shigeyuki Yamada ◽  
Masaya Sato ◽  
Tsutomu Konno
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Oxygen Atom ◽  
Liquid Crystalline ◽  
Color Change ◽  
Photophysical Properties ◽  
Structure Property ◽  
Flexible Chain ◽  
Structure Property Relationships ◽  
Chiral Nematic

The liquid-crystalline (LC) and photophysical properties of molecules are very sensitive to their electronic and molecular aggregate structures. Herein, to shed light on the structure–property relationships of pentafluorinated bistolane-based photoluminescence (PL) liquid crystals (PLLCs) previously reported by our group, we synthesized pentafluorinated bistolanes with variable flexible chains and evaluated their LC and photophysical properties. The incorporation of an oxygen atom (to afford a 2-methoxyethoxy unit) or an oxygen atom and a methyl group (to afford a 1-methoxyprop-2-oxy unit) into the flexible butoxy chain significantly decreased the temperature of the crystalline-to-LC phase transition, and a chiral nematic phase comprising helical molecular aggregates was observed for the chiral 1-methoxyprop-2-oxy group–bearing bistolane. The synthesized bistolanes exhibited strong blue PL in both solution and crystalline phases; the featuring PL characteristics were maintained in the LC phase (produced by the crystalline-to-LC phase transition) except for a slight PL color change. Thus, it was concluded that the PL behavior of pentafluorinated bistolanes can be modulated by the choice of a suitable flexible chain, and the obtained insights are believed to facilitate the application of PLLCs in thermosensing PL materials.

Synthesis and Photophysical Study of Divalent Complexes of Chelating Schiff Base

2020 ◽  
Vol 1 (01) ◽  
pp. 5-16
Author(s):  
Alaa A. Rashad ◽  
Farah Muaiad ◽  
Ahmed Ahmed ◽  
EkhlasA. Salman ◽  
Evon Akram
Keyword(s):  
Schiff Base ◽  
Surface Morphology ◽  
Theoretical Study ◽  
Energy Gap ◽  
Photophysical Properties ◽  
Schiff Base Complex ◽  
Tetrahedral Geometry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Square Planar

 Background: Schiff base compounds derivative from1,2,4-triazole, and their transition metal complexes play an essential role in coordination and bioinorganic chemistry due to biological and industrial applications. Objective: The work aims to prepare and characterize of 1, 2, 4-triazole Schiff base and its complexes with a theoretical study using  PM3 calculation and HyperChem program, photophysical properties, and surface morphology for these complexes. Methods: 1, 2, 4-triazole Schiff base prepared by condensation reaction between  4-Amino-3-mercapto-5-phenyl-4H-1,2,4-triazole and 2-hydroxy-1-naphthaldehyde, then Schiff base reacted with Co2+, Ni2+,  and Cu2+ ions,   the synthesized 1, 2, 4-triazole Schiff base, and its complexes were characterized by infrared spectra, magnetic susceptibility, conductivity measurements, photophysical properties, and surface morphology measured by atomic force microscopy. The practical results were reinforced with a theoretical study for these Schiff base complexes. Then the proposed structures of the prepared complexes. Results: 1, 2, 4-triazole Schiff base act as a chelate ligand. The coordination has occurred through the oxygen of the phenolic group O-H and the nitrogen of the imine group N=C of Schiff base with divalent metal ions. Cobalt complex has a tetrahedral geometry, while the nickel and copper complexes have square planar geometries. The stability of all compounds was studied by calculating the energy gap by diffuse reflectance spectroscopy and theoretical calculations. Copper Schiff base is a more stable complex due to the lower value of the energy gap, and the copper Schiff base complex is more semiconductivity than the other complexes. Surface morphology, properties of chelating  Schiff base ligand and its complexes measured by atomic force microscopy, cobalt Schiff base complex is higher roughness. The bond length of (-C=N-), (-C-O-),(M-O), and (M-N)  are affected in the coordination with metal ions, the bond length of the square planar geometry more affected than tetrahedral geometry. Conclusion: All compounds were prepared successfully, characterized, and photophysical properties were studied.  

Novel Azopyridine-Containing Silver Mesogens:  Synthesis, Liquid-Crystalline, and Photophysical Properties

2002 ◽  
Vol 14 (6) ◽  
pp. 2687-2692 ◽  
Author(s):  
P. K. Sudhadevi Antharjanam ◽  
V. Ajay Mallia ◽  
Suresh Das
Keyword(s):  
Liquid Crystalline ◽  
Photophysical Properties

Preparation and photophysical properties of monomeric liquid-crystalline azo-dyes embedded in bulk and film SiO2-sonogel glasses

2010 ◽  
Vol 56 (1) ◽  
pp. 7-18 ◽  
Author(s):  
V. Torres-Zúñiga ◽  
O. G. Morales-Saavedra ◽  
E. Rivera ◽  
R. Castañeda-Guzmán ◽  
J. G. Bañuelos ◽  
...  
Keyword(s):  
Azo Dyes ◽  
Liquid Crystalline ◽  
Photophysical Properties

scholarly journals Photophysical and Photochemical Properties of Green Fluorescent Liquid Crystalline Systems

2003 ◽  
Vol 58 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Ivo Grabchev ◽  
Jean-Marc Chovelon
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Liquid Crystalline ◽  
Photophysical Properties ◽  
Orientational Order ◽  
Polymer Dispersed Liquid Crystal ◽  
Polymer Dispersed ◽  
Photochemical Properties ◽  
Green Fluorescent ◽  
Naphthalimide Dye

The photophysical properties of polymer-dispersed liquid crystal systems, containing naphthalimide dye as fluorescent units are reported. Investigations have been carried out on some 1,8- naphtalimide derivatives both in isotropic and anisotropic media, and their photophysal properties have been described. The orientational order parameters of the dyes in nematic liquid crystal ZLI 1840 have been determined. The photostability of the dye/liquid crystal systems has been investigated and the effect that the substituents in the naphthalimide structure have upon the orientation of the dye was discussed.

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