The synthesis of new insecticidal
-dimethyspiro-cyclopropanes derived from pyrrolidine-2,3-dione have been described, and their biological effect against different insect species has been evaluated. ...The presented results demonstrate the excellent insecticidal activity of cyclopropane
against
and
. Cyclopropane
showed the quickest knockdown and the best killing against
and
compared to
-chrysanthemic acid and pyrethrin. The biological results of the high insecticidal activity were confirmed by the results of docking. This is evident in the binding affinity obtained for cyclopropane
, indicating good binding with an important active amino acid residue of the 5FT3 protein.
Dielectric and electro-optic properties have been studied in order to understand the effect of the fluoro-substitution on hydrogen bonded liquid crystal proprieties. The fluoro-substitution alters ...the characteristics of pure LC structure and changes its physical parameters. In the present paper, variation in physical parameters like dielectric permittivity, response time, elastic constant, rotational viscosity etc. has been explained based on many factors. In addition, the fluorine substitution has lead to the appearance of the polar nematic phase.
Nematic phase at room temperature with wide stability and high birefringence is particularly desirable for functional devices. Two thermotropic liquid crystals (tolane and the ...4-pentyl-4-biphenylcarbonitrile nematic also known as 5CB) are mixed by varying the weight fraction (wt%) in order to investigate the phase sequences and their physical properties using differential scanning calorimetry (DSC), polarised optical microscopy (POM) and dielectric spectroscopy techniques. Phase coexistence was observed for a concentrations 20 ≤ C ≤ 60 wt% of tolane in 5CB and the phase diagram was established. In addition, the nematic-isotropic temperature T
NI
increases with increasing the concentration of tolane LCs. A eutectic mixture at room temperature with large nematic range and high birefringence is obtained for C = 10 wt%. The increase in the nematic range is due to an enhancement of the nematic order induced by the LCs. It is found that the electro optical parameters like the threshold voltage, the response time were relatively increased. This increment can be attributed to an increase in the viscoelastic properties of the mixture.
A series of P
5+
- doped La
2
Mo
2
O
9
phases with different concentrations of P
5+
were prepared using conventional solid-state reactions. The formation of phase-pure P
5+
-doped La
2
Mo
2
O
9
has ...been monitored by powder X-ray diffraction, thermal analysis, conductivity measurements, Raman, and FT-IR absorption techniques. The structure and lattice parameters of La
2
Mo
2−
y
P
y
O
9−
y
/2
are obtained from Rietveld refinement. The effect of substituting P for Mo reveals that the phase transition which occurs in La
2
Mo
2
O
9
around 560 °C disappears when
y
> 0.02, as demonstrated by thermal analysis. Pure P
5+
-doped phases with monoclinic structure (α-form, the space group
P
2
1
) were observed for the concentration of optically active ions up to
y
= 0.02. When the concentration of P
5+
ions is higher, a cubic structure (β-form, the space group
P
2
1
3) starts to appear. However, up to the concentration of
y
= 0.03 of the P
5+
ion a mixture of the monoclinic and cubic phases has been observed. From infrared and Raman analysis it is confirmed that different vibration modes arise from the vibration of molybdenum-oxygen bands. Mo-O bond lengths are also found to be independent of P-doping.
Combining XRD, DTA, FTIR, Raman and conductivity measurements, a thorough investigation of the solid solutions La
2
Mo
2
y
P
y
O
9−
y
/2
(
y
= 0.01 to 0.05) was revealed.
Nowadays, in parallel to the appearance of the COVID-19 virus, the risk of viruses in water increases leading to the necessity of developing novel disinfection methods. This review focuses on the ...route of virus contamination in water and introduces non-thermal plasma technology as a promising method for the inactivation of viruses. Effects of essential parameters affecting the non-thermal discharge for viral inactivation have been exposed. The review has also illustrated a critical discussion of this technology with other advanced oxidation processes. Additionally, the inactivation mechanisms have also been detailed based on reactive oxygen and nitrogen species.
A new series of hydrogen-bonded liquid crystals was prepared by mixing 4-n-alkoxy-2.3-difluorobenzoic acid and 4-pentyl-4-biphenylcarbonitrile (5CB). Thermal and liquid crystal behaviour was ...established using differential scanning calorimetry and polarizing optical microscopy. The influence of terminal acid donors on mesogenic behaviour was discussed in detail. It was found that all complexes with a (1:1) molar ratio exhibit the smectic B phase. In addition, the binary phase diagram that has been established revealed that the mixtures with lower concentration exhibit a nematic phase at room temperature with large stability. Dielectric, electro-optic and viscoelastic properties of 5CB/9OBAFF with molar fraction x = 0.1 were discussed.
The present work reported the synthesis and characterisation of β-cyclodextrin (βCD) grafted into silica (SiO
2
@βCD) nanoparticles (NPs). Morphology analysis shows that the prepared NPs have a ...spherical shape with 170 nm of size. The electro-optic, dielectric and viscoelastic properties of SiO
2
@βCD doped nematic 5CB were examined in different concentrations of the NPs. A decrease in clearing temperature, birefringence and the order of the nanocomposite systems as compared to the pure system was observed. Dielectric parameters of pure and doped samples were measured in the frequency range of 1-2 MHz. Ionic conductivity and dielectric anisotropy increase significantly with NPs concentration due to the strong dipole moment and polarisability of SiO
2
@βCD. The advantage of dopedSiO
2
@βCDnematic 5CB is attributed to the significant decrements in threshold voltage by 32% and strong additional coupling of the electrical dipole moments in the spherical NPs with the nematic director field. On the other hand, it is found that the NPs exhibit a decreasing effect on the response time of the nematic liquid crystal, which is demonstrated by the decrement in the viscosity. The results indicate that doping SiO
2
@βCD is appropriate to fabricate a fast response LC device.
Hydrogen bonded liquid crystal, possessing a wide temperature range of cybotactic phase was used as a matrix to disperse ferroelectric LiNbO3 nanoparticles at the concentrations from 0.5 wt.% to ...3.0 wt.%. The influence of nanoparticles on the physical properties has been studied with the help of polarizing optical microscopy (POM), impedance spectroscopy and electro-optic measurements. POM investigation revealed a nematic droplet dispersed in the isotropic phase due to the addition of ferroelectric nanoparticles. The suppression of the polarization has been observed and explained by the occurrence of antiparallel dipole configuration. The isotropic-nematic phase transition temperature was decreased due to the reduction in the parameter order. The decreasing in dielectric anisotropy (∆ε), response time (τ) and in threshold Freedericksz voltage (Vth) was associated to the decrease in splay constant elastic (K11) and in the rotational viscosity (γ). The curves of ∆ε, Vth, τ, K11 and γ when NPs concentration increases, showed a minimum at the same concentration (c = 1 wt.%) allowing the determination of the optimal NPs concentration.
•Nematic-isotropic transition temperature decreases.•The nematic droplet dispersed in isotropic phase is observed.•The nanoparticles concentration dependence of the dielectric permittivity is illustrated.•The nanoparticles concentration dependence of the electro-optic and viscoelastic is presented and discussed.
•The synthesis of (C6H8NO)3ZnCl4ZnCl3(H2O) was carried out at room temperature by the slow evaporation method.•The vibrational frequencies were also predicted from the calculated intensities by the ...DFT method and were compared with the experimental frequencies.•This compound was characterized by thermal analysis between 30 °C and 800 °C.•The optical and the emission properties were elucidated.•The antimicrobial activities and in vitro enzyme inhibition assays of the targeted compound were performed.
This work centers around the search for sophisticated hybrid compounds with versatile applications. A new compound, denoted as (C6H8NO)3ZnCl4ZnCl3(H2O) (1), was synthesized and thoroughly characterized. The structural features were determined through the use of various analytical techniques, including spectroscopy (FT-IR, Raman), thermo-gravimetric analysis, and optical studies encompassing ultraviolet-visible spectroscopy, nonlinear optical (NLO), and fluorescence measurements. The crystalline arrangement was explored through single crystal X-ray diffraction analysis, revealing a triclinic crystal system with the P1¯ space group. The molecular composition comprises three distinct mono-protonated p-aminophenol (C6H8NO)+ cations alongside two isolated tetrahedral anions (ZnCl42− and ZnCl3(H2O)−). The stabilization of this hybrid compound accounts for a wide array of interactions, including hydrogen bonds and π–π (ring-ring) interactions, as deduced from comprehensive analyses. Theoretical investigations were conducted employing density functional theory (DFT) at the Cam-B3LYP/Lanl2dz level, accompanied by a detailed examination of the atoms in molecules (AIM) utilizing the BCP point. Furthermore, the nonlinear optical (NLO) properties were assessed, encompassing the evaluation of dipole moment, linear polarizability, and second hyperpolarizability. Notably, the compound exhibited pronounced solid-state fluorescence when excited at 350 nm, displaying intense emission within the blue spectrum. The correlated color temperature (CCT) value was measured at 7011 K, indicative of a "cool" white light emission. Basically, the synthesized compound exhibited antibacterial efficiency against several strains of human pathogenic bacteria in vitro and considerable enzyme inhibitory activity against pathogenic microorganisms. This research underscores the characteristics of (1), making it an appealing contender for a variety of applications.
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A series of novel naphthopyrano2,3-dpyrimidin-11(12H)-one containing isoxazole nucleus 4 was synthesized under microwave irradiation and classical conditions in moderate to excellent yields upon ...1,3-dipolar cycloaddition reaction using various arylnitrile oxides under copper(I) catalyst. A one-pot, three-component reaction, N-propargylation and Dimroth rearrangement were used as the key steps for the preparation of the dipolarophiles3. The structures of the synthesized compounds were established by 1H NMR, 13C NMR and HRMS-ES means. The present study aims to also predict the theoretical assembly of the COVID-19 protease (SARS-CoV-2 Mpro) and to discover in advance whether this protein can be targeted by the compounds 4a–1 and thus be synthesized. The docking scores of these compounds were compared to those of the co-crystallized native ligand inhibitor (N3) which was used as a reference standard. The results showed that all the synthesized compounds (4a–l) gave interesting binding scores compared to those of N3 inhibitor. It was found that compounds 4a, 4e and 4i achieved greatly similar binding scores and modes of interaction than N3, indicating promising affinity towards SARS-CoV-2 Mpro. On the other hand, the derivatives 4k, 4h and 4j showed binding energy scores (−8.9, −8.5 and −8.4 kcal/mol, respectively) higher than the Mpro N3 inhibitor (−7.0 kcal/mol), revealing, in their turn, a strong interaction with the target protease, although their interactions were not entirely comparable to that of the reference N3.
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