Is the regulation of the electronic properties of organic molecules by polynuclear superhalogens more effective than that by mononuclear superhalogens? A high-level ab initio case study

Abstract

The regulation of the electronic properties of organic molecules induced by polynuclear superhalogens is theoretically explored here for sixteen composite structures. It is clearly indicated by the higher vertical electron detachment energy (VDE) that polynuclear superhalogens are more effective in regulating the electronic properties than mononuclear structures. However, this enhanced regulation is not only determined by superhalogens themselves but also related to the distribution of the extra electron of the final composites. The composites, in which the extra electron is mainly aggregated into the superhalogen moiety, will possess higher VDE values, as reported in the case of C1', 7.12 eV at the CCSD(T) level. This is probably due to the fact that, compared with organic molecules, superhalogens possess stronger attraction towards the extra electron and thus should lead to lower energies of the extra electrons and to higher VDE values eventually. Compared with CCSD(T), the Outer Valence Green's Function (OVGF) method fails completely for composite structures containing Cl atoms, while MP2 results are generally consistent in terms of the relative order of VDEs. Actually if the extra electron distribution of the systems could be approximated by the HOMO, the results at the OVGF level will be consistent with the CCSD(T) results. Conversely, the difference in VDEs between OVGF and CCSD(T) is significantly large. Besides superhalogen properties, the structures, relative stabilities and thermodynamic stabilities with respect to various fragmentation channels were also investigated for all the composite structures.

Mg3F7: A superhalogen with potential for new nanomaterials design

“…The vertical electron detachment energies of the Mg 3 F 7 − isomers calculated at the OVGF/6‐311+G(3df) level are provided in Figure , while those obtained at the CCSD(T)/6‐311+G(3df) are shown in Table for comparison. On the basis of our and other's experience, we consider the VDEs calculated at the OVGF/6‐311+G(3df) theory level as the most reliable results, and we limit our discussion to these values. The only issue we want to raise considering this comparison is the observation that the VDEs are underestimated at the CCSD(T) level of theory (with respect to OVGF values).…”

Electron affinity of modified benzene

“…Until recently, much of the research on super‐ and hyper‐halogens focused on inorganic constituents. This is because the electron affinities of organic molecules are rather small.…”

Superhalogen Anions Supported by the Systems Comprising Alternately Aligned Boron and Nitrogen Central Atoms

“…However, the number of ligands bound to a single central atom cannot be increased beyond certain values (mostly due to destabilizing valence repulsion effects and steric hindrance). Hence, polynuclear superhalogen anions matching the (M n X n×k+1 ) – formula in which an excess electron density is expected to delocalize over n× k +1 electronegative ligands have been extensively studied in recent years ( Alexandrova et al, 2004 ; Anusiewicz and Skurski, 2007 ; Freza and Skurski, 2010 ; Sikorska and Skurski, 2012 ; Wileńska et al, 2014 ; Yin et al, 2014 ; Li et al, 2015a , 2015b , Li et al, 2015 M.-M. ; Czapla and Skurski, 2015 , 2018 ; Díaz-Tinoco and Ortiz, 2016a ; Díaz-Tinoco and Ortiz, 2016b ; Sun et al, 2016b ; Ding et al, 2017 ; Zhao et al, 2017 ; Anusiewicz et al, 2018 ; Cyraniak et al, 2019 ; Shi et al, 2019 ). Even though the polynuclear superhalogens investigated to date contain various central atoms (e.g., Li, Na, Mg, Ca, B, Al, Ge, Sn, P, Ti, Sb, As, V, In, Ta, Fe, Au, Pt), the systems utilizing nitrogen central atoms have not been proposed thus far.…”