Influence of Long-Chain Aliphatic Dopants on the Spectroscopic Properties of Polyketimine Containing 3,8-Diamino-6-phenylphenanthridine and Ethylene Linkage in the Main Chain. Noncovalent Interaction: Proton Transfer, Hydrogen and Halogen Bonding

Simple Bisthiocarbonohydrazone as a Sensitive, Selective, Colorimetric, and Ratiometric Fluorescent Chemosensor for Picric Acids

A bisthiocarbonohydrazone-based chemosensor molecule (R1) containing a tetrahydro-8-hydroxyquinolizine-9-carboxaldehyde moiety has been synthesized and characterized as a new ratiometric fluorescent probe for picric acid (PA). The ratiometric probe R1 is a highly selective and sensitive colorimetric chemosensor for PA. The association between the chemosensor and PA and the ratiometric performance enabled by the key role of excited state intramolecular proton transfer in the detection process are demonstrated. Selectivity experiments proved that R1 has excellent selectivity to PA over other nitroaromatic chemicals. Importantly, the ratiometric probe exhibited a noteworthy change in both colorimetric and emission color, and this key feature enables R1 to be employed for detection of PA by simple visual inspection in silica-gel-coated thin-layer chromatography plates. Probe R1 has been shown to detect PA up to 3.2 nM at pH 7.4. Microstructural features of R1 and its PA complex have been measured by a field emission scanning electron microscope, and it clearly proves that their morphological features differ dramatically both in shape and size. Density function theory and time-dependent density function theory calculations were performed to establish the sensing mechanism and the electronic properties of probe R1. Furthermore, we have demonstrated the utility of probe R1 for the detection of PA in live Vero cells for ratiometric fluorescence imaging.

Polyazomethine with vinylene and phenantridine moieties in the main chain: Synthesis, characterization, opto(electrical) properties and theoretical calculations

The opto(electrical) properties and theoretical calculations of polyazomethine with vinylene and phenantridine moieties in the main chain were investigated in the present study. 2,5-Bis(hexyloxy)-1,4-bis[(2,5-bis(hexyloxy)-4-formyl-phenylenevinylene]benzene was polymerized in solution with 3,8-diamino-6-phenylphenanthridine (PAZ-PV-Ph). The temperatures of 5% weight loss ( T5%) of the polyazomethine was observed at 356 °C in nitrogen. Electrochemical properties of thin film of the polymer were studied by differential pulse voltammetry. The HOMO level of the PAZ-PV-Ph was at −4.97 eV. The energy band gap ( Eg) was detected of approximately ∼1.9 eV. Energy band gap ( Egopt) was additionally calculated from absorption spectrum and absorption coefficient α. The absorption UV-vis spectra of polyazomethine recorded in solution showed a blue shift in comparison with the solid state. HOMO-LUMO levels and Eg were additionally calculated theoretically by density functional theory and molecular simulations of PAZ-PV-Ph are presented. Current density–voltage ( J– U) measurements were performed on ITO/PAZ-PV-Ph/Al, ITO/TiO2/PAZ-PV-Ph/Al and ITO/PEDOT/PAZ-PV-Ph:TiO2/Al devices in the dark and during irradiation with light (under illumination of 1000 W m−2). The polymer was tested using AFM technique and roughness ( Ra, Rms) along with skew and kurtosis are presented.

1,10-Phenanthrolinium ionic liquid crystals

The 1,10-phenanthrolinium cation is introduced as a new building block for the design of ionic liquid crystals. 1,10-Phenanthroline, 5-methyl-1,10-phenanthroline, 5-chloro-1,10-phenanthroline, and 4,7-diphenyl-1,10-phenanthroline were quaternized by reaction with 1,3-dibromopropane or 1,2-dibromoethane. The resulting cations were combined with dodecyl sulfate or dioctyl sulfosuccinate anions. The influence of both the cation and anion type on the thermal behavior was investigated. Several of the complexes exhibit mesomorphic behavior, with smectic E phases for the dodecyl sulfate salts and smectic A phases for the dioctyl sulfosuccinate salts. Structural models for the packing of the 1,10-phenanthrolinium and anionic moieties in the liquid-crystalline phases are presented. The ionic compounds show fluorescence in the solid state and in solution.

Ionically self-assembled terephthalylidene-bis-4-n-alkylanilines/n-decanesulfonic acid supramolecules: synthesis, mesomorphic behaviour and optical properties

This paper describes the preparation, mesomorphic and photophysical studies of a two type of calamitic molecules derived from azomethines, N,N'-(1,4-phenylenebis(methan-1-yl-1-ylidene)bis(4-pentylbenzenamine) (LCBAZ1) and N,N'-(1,4-phenylenebis(methan-1-yl-1-ylidene)bis(4-decylbenzenamine) (LCBAZ2) before and after protonation with the n-decyl sulfonic acid (DSA). The lengths of the outer spacers are four or nine methylene units connected with the imine group by phenyl ring in the para position. Liquid crystal properties of the undoped and doped azomethines are studied by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Wide-angle X-ray diffraction (WAXD) technique is used to probe the structural properties of the azomethines as well as its complexes. The lengths of the outer flexible spacers have an effect on the mesomorphic properties of the azomethines. The compound LCBAZ2 with nine methylene units exhibit smectic phases (Sm C and Sm X), while the LCBAZ1 with four methylene units exhibit nematic and smectic phases (N and Sm C). The effects of protonation on the phase transitions of the azomethines are investigated. The structure formation of (LCBAZx)(1)(DSA)(2) complexes are discussed on the basis of FTIR spectroscopy. Additionally, the azomethines before and after protonation with DSA are investigated by UV-vis and photoluminescence (PL) spectroscopy. With the exception of LCBAZ1 in its undoped state, the chloroform solution of the doped or undoped azomethines exhibit greenish fluorescence when the solutions are subjected to 400 nm excitation wavelength. It are concluded that the combination of the molecular and supramolecular engineering concepts stabilized the smectic phase.