Probing the Properties of Polynuclear Superhalogens without Halogen Ligand via ab Initio Calculations: A Case Study on Double-Bridged [Mg2 (CN)5 ](-1) Anions.
An ab initio study of the superhalogen properties of eighteen binuclear double-bridged [Mg2 (CN)5 ](-1) clusters is reported herein by using various theoretical methods. High-level CCSD(T) results indicate that all the clusters possess strong superhalogen properties owing to their high vertical electron detachment energies (VDEs), which exceed 6.8 eV (highest: 8.15 eV). The outer valence Green's function method provides inaccurate relative VDE values; hence, this method is not suitable for this kind of polynuclear superhalogens. Both the HF and MP2 results are generally consistent with the CCSD(T) level regarding the relative VDE values and-especially interesting-the average values of the HF and MP2 VDEs are extremely close to the CCSD(T) results. The distributions of the extra electrons of the anions are mainly aggregated into the terminal CN units. These distributions are apparently different from those of previously reported triple-bridged isomers and may be the reason for the decreased VDE values of the clusters. In addition, comparisons of the VDEs of binuclear and mononuclear superhalogens as well as studies of the thermodynamic stabilities with respect to the detachment of various CN(-1) ligands are also performed. These results confirm that polynuclear structures with pseudohalogen ligands can be considered as probable new superhalogens with enhanced properties.
MOE Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an, 710069, China.
Jin-Feng
JF
Li
MOE Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an, 710069, China.
Miao-Miao
MM
Li
Key Laboratory of Energy Source and Chemical Engineering, Ningxia University, Yinchuan, Ningxia, 750021, China.
Hongcun
H
Bai
MOE Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an, 710069, China.
Yin-Yin
YY
Sun
MOE Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an, 710069, China.
Jian-Li
JL
Li
MOE Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an, 710069, China. rayinyin@nwu.edu.cn.
Bing
B
Yin
ab initio calculations; computational chemistry; extra electron density; superhalogens; vertical electron detachment energy