Advanced Journal of Chemistry, Section A
Volume:5 Issue: 1, Winter 2022

Copper has been well-known for its antimicrobial properties, killing microorganisms and viruses. Scientific evidence attests the potential of copper and copper nanoparticle’s derived surfaces to combat microorganisms and viruses in the surrounding environment. Coronavirus disease 2019 has affected people’s life and undermined the economy worldwide. There are many preventive measures in practice to combat coronavirus disease as per local, national and/or World Health Organization (WHO) guidelines. However, with reference to the antibacterial and antiviral potential of copper and copper nanoparticles, respiratory face masks, phone cases and hand sanitizers are developed by incorporating copper and copper nanoparticles and made available in pandemic time. In this review, copper and copper nanoparticle’s derived preventive technologies are summarised and discussed in detail.

In this paper, quantum chemical calculations were performed on urea, cinnoline, and some cinnoline derivatives (1-8) at ab initio/HF/6-311G (d, p) level of theory using Gaussian09 and Gussview05 programs. Calculated optimized molecular structure, dipole moment (μ), polarizability (α), molecular electrostatic potential (MEP), and the first order hyperpolarizability (β) for hetero-aromatics 1 to 8, and urea (as a standard molecule) in three phases (gas phase, in presence of water and ethanol) were calculated. The effects of water and ethanol as solvents were taken into account with the aid of the polarizable continuum model (IEF-PCM). The optical properties of studied molecules are increasing in presence of solvents and their values have a direct relationship with the electric constants of solvents. There is a relationship between optical property and energy of the frontier molecular orbitals (FMOs), so these orbitals and the HOMO-LUMO energy gap (ΔE) were investigated. The nonlinear optical (NLO) materials are applied in optical devices, so they are very important. Since experimentally measurement of NLO property is hard, theoretical chemistry is useful in designing new NLO materials.

Sol-gel derived TiO2 was prepared and decorated with Au nanoparticles by photo deposition technique and examined by means of TEM, XRD, EDX, DRS, and BET-BJH analyses. The band gap was related to the Au decorated TiO2 (Au/T) and the synthesized plain TiO2 were obtained from DRS curves by 3.07 and 3.2 eV. The Au/T showed an enhanced visible light photocatalytic activity towards the Crystal violet (CV) dye in comparison to the plain TiO2 because of surface plasmon resonance phenomenon of the gold nanoparticles. A cooperative working mechanism involving the possible photoactivation of gold nanoparticles as well as surface bounded dye was proposed for the photocatalytic performance of Au/TiO2 system. During the decolorization of the CV dye, two reaction pathways including demethylation of amine sites of the chromophore system and breaking of the whole conjugated chromophore skeleton competing each other. The demethylation of amine sites of CV dye took place predominantly through the raid of OH species to the dye N, N-dimethyl groups, in a stepwise manner.

The main purpose of the current research was the synthesis of a novel nanomagnetic adsorbent modified with Thiol containing groups and investigating its adsorption behavior for effective elimination of heavy metal ions from environmental waters. To this end, first, the co-precipitation method was utilized to prepare Thiol-modified magnetite nanoparticles (NPs). Then, the surface of magnetic NPs was modified with Thiourea formaldehyde polymeric material, followed by purification and identification of the synthesized products. Finally, the efficiency and performance of the synthesized nanoparticles for heavy metal ions removal were investigated in the aqueous solution. The synthesis mechanism of modified nanomagnetic adsorbents were investigated and identified through various analyses including (FT-IR), (XRD), (SEM) and (VSM). The results indicated that modified nanomagnetic adsorbents were able to remove and extract the chromium (II) and cobalt (II) from aqueous solutions. Further, Langmuir and Freundlich adsorption isotherms were studied and the results showed that adsorption data of both analytes were fitted well with Langmuir isotherm. Thus, the single-layer adsorption mechanism and the homogeneous adsorbent surface can be considered.

In this study, single-phase bismuth ferrite (BiFeO3) was synthesized using hydrothermal method. The effect of KOH concentration and temperature during the reaction on morphology, particle size, and phase formation was investigated. Then, the structural properties of the samples were assessed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) analysis. XRD analysis results revealed that the samples were fabricated in distorted rhombohedral perovskite structure with R3C space group. Also, BiFeO3 (BFO) was formed in a single-phase at 220 °C and 4M concentration of KOH. The magnetic properties of the optimal sample were determined by VSM analysis and very weak magnetic properties were observed in pure nanoparticles. Also, the optical properties and photocatalytic properties of the optimal sample were investigated by UV-visible and Photoluminescence (PL) analysis. The optical gap of BFO was recorded by 2.8 and its photocatalytic properties were investigated at three different pHs (2, 6, and 10) at a concentration of 20 ppm Congo red. The results demonstrated that BFO nanoparticles nearly destroyed dye structure after 120 min at pH = 2.

Alzheimer's disease (AD) is a neurodegenerative ailment that affects many people worldwide. Its cause has yet to be determined. One of the symptoms of AD is the loss of cholinergic transmission, which is related to cognitive impairment and memory loss. Acetylcholinesterase (AChE) inhibitors like donepezil, galantamine, and rivastigmine are currently used in medicine, but they have been taken off the market due to their adverse side effects. Molecular docking simulation was used to simulate and design some tacrine derivatives because of the inhibitory ability of tacrine on the enzyme AChE. This study was tailored to theoretically calculate the tacrine derivatives binding scores and design some potent Alzheimer's inhibitors. After docking, molecule A8 has the highest binding scores of -9.8 kcal/mol, and it was chosen as a template for designing new compounds. Five new hypothetical molecules (B3, B5, B6, B8, and B10) were designed. ADMET prediction of the designed molecules and drug-likeness show good pharmacokinetic abilities. Moreover, the in-silico techniques used in this study could further design similar potent inhibitor compounds against AD.

Organic pi-conjugated compounds have attracted the interest of many researchers world wide due to their stability, high conductivity and intriguing optoelectrical properties. In this study, theoretical calculations were carried out to investigate the effect of electron-withdrawing and electron-donating groups at a different position on electronic properties, geometry and photophysical parameters of bithiophene and bipyridine ring linked by a single bond using density functional theory (DFT) and time dependent DFT (TD-DFT). The calculated energy gap (Eg) of the studied co-oligomers with substituents decreased with substituent strength. The reduction in the value of ɳ (1.54eV to 1.8eV) of the substituted co-oligomers compared with 1.95eV of unsubstituted co-oligomer implies lower resistance to distortion which enhances electron-withdrawing. The theoretical maximum absorption (λ-max) values for substituted compounds range between 335.4nm to 404.2nm compared with 318.2nm of an unsubstituted compound. Hence, the study results show that the substitute groups' nature, species, and position affect both the electronic and absorption properties without any significant difference in the geometry of the bithiophene-bipyridine co-oligomer. The mutual comparison of substituted and unsubstituted compounds shows a decrease in energy gap (Eg) and significantly reflected bathochromic shift for all substituted compounds, especially compound with NO2 substituent, indicating that the HOMO and LUMO level of the studied compounds were well controlled by the attached substituents groups. Hence, it is expected to be useful for opto electronic material design.