Periodic Table of the Elements, History, Education and Evaluation

The periodic tables of transition metal thiophosphates MPS3, transition metal dichalcogenides MX2 and other materials, the origin of chemical elements and toxic trace elements in dried mushrooms are provided. The effective nucleus-electron attraction is proportional to the effective nuclear charge (Zeff) and inversely proportional to the effective principal quantum number (n*). The periodic arch is one of many modern visual displays that have been developed to augment the traditional periodic table of the chemical elements. The table is related with the multiparameter optimisation of N atom, nuclear magnetic resonance and everyday life. Educational activities are developed with evaluation.

Calculation of Arrhenius Parameters by the Rrkm Method for the Carbon–Hydrogen Bond Fission Reaction of Fluorobenzene

The present study provides quantitative results for the rate of the unimolecular hydrogen–carbon bond fission reaction of fluorobenzene at elevated temperatures up to 2000 K. The potential energy surfaces for each C–H bond fission reaction (in the ortho, meta, and para sites) of fluorobenzene were investigated using ab initio calculations. The geometry and vibrational frequencies of the species involved in these reactions were optimised at the unrestricted MP2 level of theory, using the cc-pVDZ basis set. Since the C–H bond fission channel is a barrier-less reaction, we have used variational Rice–Ramsperger–Kassel–Marcus (RRKM) theory to predict rate constants. The difficulty in the application of the RRKM method to molecules bigger than benzene is discussed and a method is offered to solve the problem. Using calculated rate constants at different temperatures, the activation energies and exponential factors were determined. The Arrhenius expressions for the C–H bond fission reactions of fluorobenzene at the ortho, meta and para sites were obtained as k( T) = 6.1 × 1016 e−57328/ T, k( T) = 1.8 × 1017 e−59080/ T and k( T) = 1.3 × 1017 e−59600/ T respectively. Moreover, the effect of the fluorine atom including electron attraction and resonance with the benzene ring, on molecular rotation and the tunnelling effect on the rate expression have been discussed.

Theoretical Study on Ru2+, Cu+, and Fe2+ Complexes Toward the Application in Dye Sensitized Solar Cell

This paper reports the application of the Ru2+, Cu+, and Fe2+ complexes in form of RuL2(SCN)2, CuL2(SCN)2− for dye-sensitized solar cell (DSSC) development. The calculation results, given by quantum chemistry, demonstrated that the complex containing copper is more suitable than the one containing iron. The modification of Cu(I) complex by using various numbers of ligands enhanced photon absorption capacity as well as the absorption range. The addition of an organic ligand such as an electron attraction group to the benzene ring gave a better result as compared to the inorganic ones. Based on the analysis conducted, CuM2(SCN)2− is considered as potential material for N3 replacement.