Concentration effects on optical properties, DFT, crystal characterization and α-glucosidase activity studies: Novel Zn(II) complex

Designing efficient materials for high-performance of non-fullerene organic solar cells through side-chain engineering on DBT-4F derivatives by non-fused-ring electron acceptors

CONTEXT

For the advancement in fields of organic and perovskite solar cells, various techniques of structural alterations are being employed on previously reported chromophores. In this study, the end-capped engineering is carried out on DBT-4F (R) by modifying terminal acceptors to improve optoelectronic and photovoltaic attributes. Seven molecules (AD1-AD7) are modeled using different push-pull acceptors. DFT/B3LYP/6-31G along with its time-dependent approach (TD-DFT) are on a payroll to investigate ground state geometries, absorption maxima (λmax), energy gap (Eg), excitation energy (Ex), internal reorganization energy, light harvesting efficiency (LHE), dielectric constant, open circuit voltage (VOC), fill factor (FF), etc. of OSCs. AD1 displayed the lowest band gap (1.76 eV), highest λmax (876 nm), lowest Ex (1.41 eV), and lowest binding energy (0.21 eV). Among various calculated parameters, all of the sketched molecules demonstrated greater dielectric constant when compared to R. The highest dielectric constant was exhibited by AD3 (56.26). AD5 exhibited maximum LHE (0.9980). Lower reorganization energies demonstrated improved charge mobility. AD5 and AD7 (1.63 and 1.68 eV) have higher values of VOC than R (1.51 eV). All novel molecules having outperforming attributes will be better candidates to enhance the efficacy of OSCs for future use.

METHODS

Precisely, a DFT and TD-DFT analysis on all of the proposed organic molecules were conducted, using the functional MPW1PW91 at 6-31G (d,p) basis set to examine their optoelectronic aspects, additionally the solvent-state computations were studied with a TD-SCF simulation. For all these simulations, Guassian 09 and GuassView 5.0 were employed. Moreover, the Origin 6.0, Multiwfn 3.8, and PyMOlyze 1.1 software were utilized for the visual depiction of the graphs of absorption, TDM, and DOS, respectively of the studied molecules. A number of crucial aspects such as FMOs, bandgaps, light-harvesting efficiency, electrostatic potential, dipole moment, ionization potential, open-circuit voltage, fill factor, binding energy, interaction coefficient, chemical hardness-softness, and electrophilicity index were also investigated for the studied molecules.

A Zn-coordination polymer for the quantitative and selective colorimetric detection of residual tetracycline in aqueous solution and urine

A one-step solvothermal synthesis provides a functional crystalline one-dimensional Zn-coordination polymer (Zn-CP) with excellent stability in aqueous solution over a wide range of temperature and pH. Zn-CP is a rapid, highly sensitive and selective sensor for detecting tetracycline (TC). Quantitative TC detection is based on the ratio of fluorescence intensities I₅₃₀/I₄₂₀, with a limit of detection (LOD) of 5.51 nM in aqueous solution and 47.17 nM in human urine. The characteristics of colorimetric TC sensing by Zn-CP are highly favorable for application because the color of Zn-CP changes in the visible part of the spectrum from blue-purple to yellow-green upon addition of TC. Conversion of these colors into an RGB signal is simply achieved with an app for the smart phone and provides LODs of 8.04 nM and 0.13 μM TC in water and urine, respectively. Our suggested sensing mechanisms assume that the fluorescence intensity of Zn-CP@TC at 530 nm is enhanced by energy transfer of Zn-CP to TC, while the fluorescence of Zn-CP at 420 nm is quenched by photoinduced electron transfer (PET) from TC to the organic ligand in Zn-CP. These fluorescence properties make Zn-CP a convenient, low-cost, rapid and green detection device for monitoring TC under physiological conditions and in aqueous media.

A review on α-glucosidase inhibitory activity of first row transition metal complexes: a futuristic strategy for treatment of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by high blood glucose levels and has emerged as a controversial public health issue worldwide. The increasing number of patients with T2DM on one hand, and serious long-term complications of the disease such as obesity, neuropathy, and vascular disorders on the other hand, have induced a huge economic impact on society globally. In this regard, inhibition of α-glucosidase, the enzyme responsible for the hydrolysis of carbohydrates in the body has been the main therapeutic approach to the treatment of T2DM. As α-glucosidase inhibitors (α-GIs) have occupied a special position in the current research and prescription drugs are generally α-GIs, researchers have been encouraged to design and synthesize novel and efficient inhibitors. Previously, the presence of a sugar moiety seemed to be crucial for designing α-GIs since they can attach to the carbohydrate binding site of the enzyme mimicking the structure of disaccharides or oligosaccharides. However, inhibitors lacking glycosyl structures have also shown potent inhibitory activity and development of non-sugar based inhibitors is accelerating. In this respect, in vitro anti-α-glucosidase activity of metal complexes has attracted lots of attention and this paper has reviewed the inhibitory activity of first-row transition metal complexes toward α-glucosidase and discussed their probable mechanisms of action.