Novel Grafted Hydrogel for Iron and Ammonia Removal from Groundwater: A Synthesis and Computational Chemistry Study.

Current research is moving towards iron and ammonia elimination from groundwater. Here, we are using a poly acrylic-poly acrylamide hydrogel that is grafted with 3-chloroaniline. This copolymer was synthesized by addition polymerization technique. The effects of agitation time, dosage and adsorbent temperature on the removal process sensitivity were investigated. The copolymer was described experientially and theoretically. Isothermal kinetic adsorption models are discussed. This hydrogel could be regenerated efficiently (98.3% removal of iron and 100% removal of ammonia). The density functional theory (DFT) method, using B3LYP/6-311G(d,p), and the LANL2DZ level of the theory were managed to investigate the stationary states of the grafted copolymer and the complexation energy of the hydrogel with the studied cations. DFT has been used to investigate the Natural Bond Orbital (NBO) properties to locate the most negative centers on the hydrogel. The calculated complexation energy showed hydrogel selectivity with regard to the studied cations.

Designing Efficient Metal-Free Dye-Sensitized Solar Cells: A Detailed Computational Study.

The modulation of molecular characteristics in metal-free organic dyes holds significant importance in dye-sensitized solar cells (DSSCs). The D-π-A molecular design, based on the furan moiety (π) in the conjugated spacer between the arylamine (D) and the 2-cyanoacrylic acid (A), was developed and theoretically evaluated for its potential application in DSSCs. Utilizing linear response time-dependent density functional theory (TDDFT) with the CAM-B3LYP functional, different donor and acceptor groups were characterized in terms of the electronic absorption properties of these dyes. All the studied dye sensitizers demonstrate the ability to inject electrons into the semiconductor's conduction band (TiO2) and undergo regeneration through the redox potential triiodide/iodide (I3-/I-) electrode. TDDFT results indicate that the dyes with CSSH anchoring groups exhibit improved optoelectronic properties compared to other dyes. Further, the photophysical properties of all dyes absorbed on a Ti(OH)4 model were explored and reported. The observed results indicate that bidentate chemisorption occurs between dyes and TiO4H5. Furthermore, the HOMO-LUMO energy gaps for almost all dye complexes are significantly smaller than those of the free dyes. This decrease of the HOMO-LUMO energy gaps in the dye complexes facilitates electron excitation, and thus more photons can be adsorbed, guaranteeing larger values of efficiency and short-circuit current density.

Efficient D-π-π-A-Type Dye Sensitizer Based on a Benzothiadiazole Moiety: A Computational Study.

The design of highly efficient sensitizers is one of the most significant areas in dye-sensitized solar cell (DSSC) research. We studied a series of benzothiadiazole-based D-π-π-A organic dyes, putting emphasis on the influence of the donor moiety on the DSSC's efficiency. Using (linear-response time-dependent) density functional theory ((TD)DFT)) with the CAM-B3LYP functional, different donor groups were characterized in terms of electronic absorption spectra and key photovoltaic parameters. As a reference, a dye was considered that had a benzothiadiazole fragment linked via thiophene rings to a diphenylamine donor and a cyanoacrylic-acid acceptor. The different systems were first studied in terms of individual performance parameters, which eventually aggregated into power conversion efficiency. Only the amino-substituted species showed a modest increase, whereas the dimethylamino case showed a decrease.

Boron nitride nanoclusters, nanoparticles and nanotubes as a drug carrier for isoniazid anti-tuberculosis drug, computational chemistry approaches.

In this work, the ability of B12N12 fullerene-like nanoclusters as a drug carrier for isoniazid anti-tuberculosis drug has been studied by DFT methods. Binding energies in both gas and water phases are reported. The formed bonds between B12N12-FLN and Iso drug are studied and computed using QMAIM method. NPA is computed to obtain the total charges transferred in the B12N12-FLN-Iso drug complexes, NPA obtained values suggested that the cluster may oxidize the coordinated of Iso drug. The charge-transfer energy values are also computed and confirmed that the charges were transferred from the non-bonding lone-pair (n) of N and O atoms orbitals to the σ* orbitals of B and N atoms of B12N12-FLN. Also, the adsorption of Iso drug on BN nanoparticles surface (different sizes and shapes) and BN nanotubes was studied by Monte Carlo simulation. We found that increasing the BN size did not affect significantly on the adsorption energies of Iso drug for all various BN nanoparticles shapes. All adsorption energies obtained by MC calculations are negative values which revealed that the adsorption of the Iso drug molecule on BN surfaces is exothermic, spontaneous and energetically favourable. Also, the stability of B12N12-FLN-Iso drug complex in water explicitly was studied by MD simulations. MD simulation confirmed that iso-B12N12-FLN complexes are stable in the presence of water molecules. So, finally, we deduced that B12N12 fullerene-like nanoclusters can be acted as a drug carrier for isoniazid anti-tuberculosis drug. Communicated by Ramaswamy H. Sarma.

Carbonyl vibrational wave packet circulation in Mn2(CO)10 driven by ultrashort polarized laser pulses.

The excitation of the degenerate E(1) carbonyl stretching vibrations in dimanganese decacarbonyl is shown to trigger wave packet circulation in the subspace of these two modes. On the time scale of about 5 ps, intramolecular anharmonic couplings do not cause appreciable disturbance, even under conditions where the two E(1) modes are excited by up to about two vibrational quanta each. The compactness of the circulating wave packet is shown to depend strongly on the excitation conditions, such as pulse duration and field strength. Numerical results for the solution of the seven-dimensional vibrational Schrödinger equation are obtained for a density functional theory based potential energy surface and using the multi-configuration time-dependent Hartree method.

Laser control of single and double proton transfer reactions.

Theory and simulation of laser control of single and double proton transfer reactions in hydrogen-bonded molecular systems are reviewed. Different approaches to the construction of potential energy surfaces are introduced as a means to design simple models for unraveling basic mechanistic principles of laser control. Obtaining the control laser field is the central task and various methods such as optimal control theory are outlined. Applications are presented for the infrared laser-driven single proton transfer in models of thioacetylacetone and acetylacetone as well as for the double proton transfer in porphycene derivatives.