Theoretical investigation on the surrounding effects of second-order nonlinear properties for (N^C^N)Pt(II)Cl complexes.

Pt(II) complexes are widely used as nonlinear optical (NLO) materials. The geometric and electronic structures, second-order NLO property and UV-Vis absorption spectra of (N^C^N)Pt(II)Cl complexes (1-4) N^C^N binding by central benzene and two lateral N-heterocycles) are evaluated by density functional theory (DFT) and time-dependent DFT calculations. The detailed environmental effect of total first hyperpolarizability (β) in the solution and crystal phases is simulated by polarized continuum model (PCM) and quantum mechanics/molecular mechanics (QM/MM) method, respectively.

Enhancing bioretention efficiency for pollutant mitigation in stormwater runoff: Exploring ecosystem cycling dynamics amidst temporal variability.

In this study, three distinct bioretention setups incorporating fillers, plants, and earthworms were established to evaluate the operational efficiency under an ecosystem concept across varying time scales. The results revealed that under short-term operating conditions, extending the drying period led to a notable increase in the removal of NO-N, total phosphorus (TP), and chemical oxygen demand (COD) by 5 %-7%, 4 %-12 %, and 5 %-10 %, respectively. Conversely, under long-time operating conditions, the introduction of plants resulted in a significant boost in COD removal by 10 %-20 %, while the inclusion of earthworms improved NH-N and NO-N removal, especially TP removal by 9 %-16 %.

Studies on the Surface Adsorption of Binary Molten Salts.

The surface adsorption of eight binary molten salts, AgNO-MNO(M = Li, Na, K, Rb), NaNO-MNO (M = K, Rb), Ca(NO)-CsNO, and Cd(NO)-NaNO, has been investigated. It is found that the surface tension and temperature of molten salts at constant pressure and mole fraction satisfy the same equation as that for pure liquid compounds reported in our previous works. The heats of phase transition from the bulk to the surface phase for eight molten salts are determined.

Design and spatial pattern optimization for a sponge city using factor analysis and geographical statistics to restore urban resilience: A case study in a coastal area of China.

The sponge city is a new concept of stormwater management for ecological city construction, which aims to restore water-cycle processes and reduce runoff. Cities in coastal districts are suffering from serious instability due to high population density, urbanization, and land-use changes. However, previous research contains few evaluations of balancing urban ecological indicators of sponge city performance, including geographical, environmental, economic, and social factors, and their effect on resilience at a macro level to develop low-impact development schemes.

Theoretical Perspective on Two-State "ON-OFF" NLO Switch of Rh(III)-Azobenzene Complex with Considerable First Hyperpolarizability.

In this paper, a light-induced Rh(III)-azobenzene (azo) complex in its two conformations (- and -form) is analyzed via density functional theory methods, focusing on the geometrical and electronic structure, linear and second-order nonlinear optical (NLO) properties, as well as UV-vis absorption spectra. The results show that exhibits more obvious charge separation and more extensive π-conjugation than . The energy gaps () between the highest occupied molecular orbital and lowest unoccupied molecular orbital of and are as small as 0.

Block Effective Hamiltonian Theory and Its Application.

Block effective Hamiltonian theory (BEHT) is presented in this work. Configuration interaction functions are divided into , , and spaces. Effective Hamiltonian is constructed with the partitioning technique within the space.

Computational Studies on the Reactivity of Polycyclic Aromatic Hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are widely present in the environment as toxic pollutants. In this study, quantum chemistry methods are used to study reactions of PAHs in both particle and gas phases. Seven theoretical methods are exploited to predict the reactive sites of 15 PAHs in the particle phase.

Ultrastable liquid crystalline blue phase from molecular synergistic self-assembly.

Fabricating functional materials via molecular self-assembly is a promising approach, and precisely controlling the molecular building blocks of nanostructures in the self-assembly process is an essential and challenging task. Blue phase liquid crystals are fascinating self-assembled three-dimensional nanomaterials because of their potential information displays and tuneable photonic applications. However, one of the main obstacles to their applications is their narrow temperature range of a few degrees centigrade, although many prior studies have broadened it to tens via molecular design.

Quantitative description of surface adsorption of surfactant in aqueous solution without the Gibbs equation.

A new equation related to the surface tension and concentration of solute in the surface region is derived and a three-step procedure is proposed to determine the molecular area of surfactants in aqueous solution at saturation of the air-liquid surface. Based on their surface tension data, the molecular areas of hexyl, octyl and decyl trimethylammonium bromide (HTABr, OTABr and DTABr) in aqueous solutions have been calculated and are in agreement with the computational results of density functional theory. Gibbs analysis has also been carried out for these surfactants.

Rhodium-Catalyzed C(sp)-H Amidation of Azine with Sulfonamides.

Direct C-H amidation of azine with sulfonamide was developed for the first time. The reactions proceeded smoothly under benign conditions and gave the corresponding products with high selectivity. This approach shows high regioselectivity, wide substrate scope, and functional group tolerance.

Multireference Rayleigh-Schrödinger perturbation theory and its application.

Based on the complete active space multireference wavefunction, multireference Rayleigh-Schrödinger perturbation theory (MRSPT) is derived with the assumption that the orbital energies of active orbitals are the same as ε¯, an unknown parameter. In this work, ε¯ is optimized at the MRSPT2 level. The second and third order perturbation theories are shown numerically to be size extensive.

Broadband Reflection in Polymer-Stabilized Cholesteric Liquid Crystals via Thiol-Acrylate Chemistry.

Thiols are prone to react with a multitude of various functional groups in high yields, which has been widely used for surface- and particle-patterning, bioorganic synthesis, polymer modification, imprint nanolithography, the fabrication of optical components, hydrogel synthesis, and the curing of hard protective coatings. In this work, a chiral thiol with a high helical twisting power was synthesized through a novel synthetic route with high selectivity, yield, and cost-effectiveness. It was then used to fabricate a liquid-crystal composite film with ultra-wide broadband reflection via thiol click chemistry.

Nonelectric Sustaining Bistable Polymer Framework Liquid Crystal Films with a Novel Semirigid Polymer Matrix.

In this work, a bistable polymer framework liquid crystal (PFLC) thin film by thermal curing of epoxy monomers with two different thiols, a traditional flexible-structure thiol and a novel original rigid-structure thiol, has been successfully fabricated, combining a novel mixed morphology of polymer matrix and cholesteric liquid crystals with negative dielectric anisotropy. The polymer framework morphology has been formed by curing two types of epoxy monomers with two types of thiols, and the liquid crystals tend to be focal conic textures with large size domains at the initial state in the PFLC film so that it has a moderate light transmissivity at this state between the transparent state and the opaque state. Thus, the devices based on PFLC films can be switched reversibly between the transparent state and the opaque state by alternative electric field.

A Facile All-Solution-Processed Surface with High Water Contact Angle and High Water Adhesive Force.

A series of sticky superhydrophobicity surfaces with high water contact angle and high water adhesive force is facilely prepared via an all-solution-processed method based on polymerization-induced phase separation between liquid crystals (LCs) and epoxy resin, which produces layers of epoxy microspheres (EMSs) with nanofolds on the surface of a substrate. The morphologies and size distributions of EMSs are confirmed by scanning electron microscopy. Results reveal that the obtained EMS coated-surface exhibits high apparent contact angle of 152.

A new size extensive multireference perturbation theory.

A new multireference perturbation series is derived based on the Rayleigh-Schrödinger perturbation theory. It is orbitally invariant. Its computational cost is comparable to the single reference Møller-Plesset perturbation theory.

Revealing the nature of intermolecular interaction and configurational preference of the nonpolar molecular dimers (H₂)₂, (N₂)₂, and (H₂)(N₂).

Understanding the nature of noncovalent interactions between nonpolar small molecules is not only theoretically interesting but also important for practical purposes. The interaction mechanism of three prototype dimers (H₂)₂, (N₂)₂, and (H₂)(N₂) are investigated by state-of-the-art quantum chemistry calculations and energy decomposition analysis. It is shown that their configuration preferences are essentially controlled by the electrostatic component rather than the dispersion effect though the monomers have zero dipole moment.

Bond order analysis based on the Laplacian of electron density in fuzzy overlap space.

Bond order is an important concept for understanding the nature of a chemical bond. In this work, we propose a novel definition of bond order, called the Laplacian bond order (LBO), which is defined as a scaled integral of negative parts of the Laplacian of electron density in fuzzy overlap space. Many remarkable features of LBO are exemplified by numerous structurally diverse molecules.

Quantitative analysis of molecular surface based on improved Marching Tetrahedra algorithm.

Quantitative analysis of molecular surface is a valuable technique for analyzing non-covalent interaction, studying molecular recognition mode, predicting reactive site and reactivity. An efficient way to realize the analysis was first proposed by Bulat et al. (J.

Multiwfn: a multifunctional wavefunction analyzer.

Multiwfn is a multifunctional program for wavefunction analysis. Its main functions are: (1) Calculating and visualizing real space function, such as electrostatic potential and electron localization function at point, in a line, in a plane or in a spatial scope. (2) Population analysis.

A Single Reference Perturbation Theory beyond the Møller-Plesset Partition.

A new single reference perturbation partition is proposed for restricted open-shell Hartree-Fock (ROHF) and complete active space self-consistent field (CASSCF) orbitals. It is a sum of one-particle operator which is implicitly defined. When the operator acts on a ROHF or CASSCF orbital, the resultant eigenvalue is the orbital's corresponding orbital energy coming from the ROHF or CASSCF calculation.

Cation electric field is related to hydration energy.

Electronic structure calculations on ions that use dielectric continuum theory to mimic solvent around the bare ionic solutes are often prone to make large errors in the hydration energies. It is found for cations that much of the error can be accounted for by a simple linear correlation with the maximum value found anywhere on the dielectric cavity surface of the solute potential or, even better, the outgoing normal electric field, thus mirroring analogous results previously obtained for anions. This correlation allows for significantly improved estimates of cation hydration energies while still retaining cavities of physically reasonable size in determination of the bulk dielectric contributions.