Advanced Materials Research Vols. 634-638

Abstract: A number of newly Ln-N bond valence parameters were quantitatively estimated, which allowed us to obtain all Ln-N bond lengths with different coordination numbers in metal organic complexes. Twenty linear correlations among the mean bond valence parameters of Ln-O, Ln-N, Ln-S, Ln-Cl and Ln-C bonds of metal organic complexes have been well established and denoted by a set of linearity equations, which provides us a useful method to determine the bond valence parameters of other type Ln-atom bonds in coordination chemistry. The present work shows us a novel approach to deeply understand the chemical bonding characteristics between Ln and the ligands in various metal organic complexes.

Abstract: The design idea and design flow of the simulation software on the complex reaction kinetics are introduced in this article. Firstly, the total framework of the software was determined by the goal and function of the software; Secondly, the manuscript was written, the multimedia material was made and the computational programs were designed, the examples of making multimedia material by Photoshop and Flash are introduced, moreover, the thinking and method of program is introduced; Finally, The material such as text, images, sounds, animation is integrated by Authorware. The simulation software has friendly interface and simple operation, it can be used as a computational tool in studying chemical kinetics, in addition, the software can be assisted in the teaching such as physical chemistry and reaction engineering.

Abstract: The 91×91 complete energy matrix of 4f2 configuration ion praeseodymium in octahedral cubic crystal field has been constructed based upon the combination of Racah’s group-theoretical consideration with Slater’s wavefunctions. The energy levels of praseodymium (Pr3+) in hexachloride elpasolite crystals Cs2NaYCl6 have been calculated. The calculated results display a good agreement with the experimental values, which implies that the complete energy matrix method can be received as a recommendable tool to perform a theoretical analysis to the doped crystal.

Abstract: The recognition mechanism of the urea-based non-involving fluorine (A) and involving fluorine (B) derivation receptors for the chlorine anion (Cl-) was discussed by using the density function B3LYP method. The results showed that recognition mechanism was performed by using four coordination weak bonds, which include two N-H…Cl hydrogen bonds and two C-I…Cl halogen bonds. The calculated interaction energies (ΔECP) with basis set super-position error (BSSE) correction of the two systems are -121.78 and -179.71 kJ•mol-1, respectively. So, the urea-based involving fluorine derivation receptor (B) presents the better recognition capable for the Cl-. Natural bond orbital theory (NBO) analysis has been used to investigate the electronic behavior and property of the N-H…Cl hydrogen bonds and two blue-shift C-I…Cl halogen bonds in the A…Cl- and B…Cl- recognition systems, respectively.

Abstract: The mathematical model on acid-base titration was established by using analytical chemistry theory; therefore the author designed a program to solve the model by using of Visual Basic language. The program can not only calculate the pH Value of the acid-base titration solution, choose the appropriate indicator, calculate the endpoint error and judge the feasibility of the titration, but also can draw the curve of the acid-base titration.

Abstract: First-principles investigation on the inelastic electron tunneling spectra of octanethiolate molecular junctions is performed. It is demonstrated that the inelastic electron tunneling spectra are very sensitive to the molecular junction width. The varied peak height mainly caused by the different coupling energy between the electrode and molecule.

Abstract: A first-principles computational method is developed to study the inelastic electron tunneling spectroscopy (IETS) of octanethiolate molecular junctions with different orientation of the molecule adsorbed on the Au(111) surface. We have demonstrated that IETS is very sensitive to the orientation of the molecule. The computational results demonstrate that the IETS has certain selection rule for vibrational modes, where the modes with the same direction as the tunneling current have greatest contribution to the IETS.

Abstract: Zeatin belongs to the derivation of purine, and the C=C is one of the functional groups in the zeatin structure. So, there are trans- and cis- structures for the zeatin molecule. Interestingly, the trans-zeatin has biological activities, but the cis-zeatin has no obvious biological activity. The trans-zeatin is the first separated cell cytokinins from the plant tissue. And the zeatin, especially trans-zeatin has important and extensive applications in many research fields. In this study, the Geometries of the trans-zeatin and cis-zeatin were optimized by using the density function Becke, three-parameter, Lee-Yang-Parr, DFT/B3LYP/6-31G method. Additionally, FT-IR experiments were conducted for the trans-zeatin. The geometry structures and molecular vibrational property of the zeatin were simply discussed.

Abstract: The geometry structures and IR properties of the non-involving fluorine (A) and involving fluorine (B) urea-based derivation receptors used recognition for chlorine anion (Cl-) was investigated by using the density function Becke, three-parameter, Lee-Yang-Parr (B3LYP) method. The involving fluorine urea-based derivation receptor (B) presents a better recognition capable for the Cl-. In the A…Cl- recognition system, the stretch vibrational frequency of the N-H bond presents an obvious red-shift, and the red-shift value higher than 12.4 cm-1, moreover, the IR intensity increased from 8.26 km•mol-1 of the monomer to 312.12km•mol-1 of the recognition system. However, as for the C-I bonds of the halogen bond donors of the receptor molecules A and B, their stretch vibrational frequencies present the different potential shift.