Yanhua Lei

Adsorbate free energies are important parameters in surface chemistry and catalysis. Because of its simplicity, the harmonic oscillator (HO) model remains the most widely used method for calculating adsorbate free energy in many fields, including microkinetic modeling. However, it is well-known that the HO method is ineffective for weak adsorption. In this study, we propose a translational model with a diffusion barrier to calculate the state functions of near free translation. Furthermore, an effective mass is introduced in this model. To address hindered translation uniformly, a diffusion barrier-based damping function (DF) is proposed that effectively links the harmonic vibration and translation limits. Adsorbates are divided into three categories according to their adsorption strength and diffusion barrier height. Adsorbed hydrogen atoms have a strong binding energy and relatively high vibrational frequency but a low diffusion barrier. The HT and our proposed DF methods predict that the adsorbed hydrogen atoms behave as translation above room temperature, while the previous DF method predicts that they behave as vibration at any temperature. At last, the dehydrogenation reaction of propane on the Pt(111) surface was taken as an example to illustrate the influence of different methods on the thermodynamic functions.

The azine‐based bismuth (III) complex [Bi(H₂L¹)(NO₃)₃(H₂O)₂]•H₂O(1a) was synthesized by an equivalent reaction between Schiff base and Bi (NO₃)₃•5H₂O using mannitol as an auxiliary agent. During the formation of the complex (1a), the Schiff base containing 3‐methoxy group transformed into 3‐methoxysalicylaldehyde azine and further coordinated with Bi^III ion to form a mononuclear Bi^III complex (1a). Bismuth (III) ions were unexpectedly found to catalyze the formation of the azines from Schiff bases derived from pyrazinohydrazide, and their formation mechanism was further studied. Theoretical studies of the complex (1a) involving thermodynamic and electronic properties were done using the density functional theory (DFT) B3LYP method. Furthermore, in vitro biological evaluation showed that the antimicrobial and cytotoxic activities of the complex (1a) were much higher than those of free ligands. The obtained MIC and IC₅₀ values of the complex (1a) were almost close to those of the reference drugs.

Thermodynamic state functions are fundamental quantities in many fields. In this work, the van der Waals (vdW) equation of state and calculation formulas of state functions are derived with statistical thermodynamic method in three‐dimensional (3D) and two‐dimensional (2D) spaces. The heat capacity at constant volume (C_V,m) or area (C_A,m) is exactly the same as that of ideal gas, but the heat capacity at constant pressure (C_p,m) and other state functions are different from those of ideal gas. The vdW equation of state is a cubic equation, which leads to the fact that the entropy and free energy changes of vdW fluid can be expressed as explicit expressions of volume rather than pressure. Therefore, the adsorbate entropy at constant area can still be theoretically proven to have a linear relationship with the gas‐phase entropy at constant volume. However, the linear correlation between it and gas‐phase entropy at constant pressure is no longer strictly true in theory. In addition, since the vdW equation of state is applicable to both gas and liquid, the linear correlation between adsorbate entropy and liquid‐phase entropy can also be found. At last, the reference state for real gas or fluid at a constant molar volume is suggested.

A new bismuth(III) Schiff‐base complex [Bi₂(HL)₂(NO₃)₄] was synthesized by using equivalent molar of Schiff‐base ligand [H₂L = (E)‐N′‐(2‐hydroxy‐3‐methoxybenzylidene)isonicotinohydrazide] and Bi(NO₃)₃•5H₂O with the assistance of Mannitol. The complex was structurally characterized by elemental analysis, spectroscopic methods, and single crystal X‐ray diffraction. The experimental and theoretical vibrational bands (infrared and Raman spectra) have been discussed. The antimicrobial activity of the complex against Schizosaccharomyces pombe was evaluated by bio‐microcalorimetry at 32°C. Some thermokinetic parameters (k, P_max, t_G, and Q_total) were obtained from the metabolic power–time curves of S. pombe, and their quantitative relationships with the concentration (c) were discussed. The half inhibition concentrations (IC₅₀) of isoniazid, Schiff base, and the complex were calculated. The complex showed the strongest inhibition effect among three compounds.

Reaction of silver nitrate with 2‐aminobenzothiazole (abbreviated as Habt) in methanol at 45°C gave mononuclear complex of formula [Ag (Habt)₂]NO₃•CH₃OH. The structure of the complex was characterized by infrared (IR) spectra, single crystal X‐ray diffraction, and elemental analysis. X‐ray diffraction analysis indicated that the title complex was crystallized in the triclinic crystal system with space group P–1, in which silver(I) ion was coordinated to two 2‐aminobenzothiazole ligands through the benzothiazol nitrogen atom. Theoretical study of the complex was carried out by density functional theory (DFT) B3LYP method. The antimicrobial effects of the ligand and its silver(I) complex were evaluated by bio‐microcalorimetry on the growth of Schizosaccharomyces pombe (S. pombe). Some quantitative metabolic parameters, such as growth rate constant (k), maximum heat power (P_max), inhibition ratio (I), and half inhibition concentration (IC₅₀), were derived from the metabolic power–time curves of S. pombe growth. The half inhibition concentration (IC₅₀) of the ligand was calculated to be 2.58 × 10⁻³ mol L⁻¹. The complex could strongly influence the lag phase of S. pombe.

Defects favor dehydrogenation of propene to acrolein on the MoO₃(010) surface.