2. Computational details
Quantum chemical calculations on Pt(CN)n(n = 1–6) complexes and their corresponding supersalts and
superacids were performed utilizing DFT [43,44] with B3LYP
[45,46]. SDD basis set [47,48] supplemented with
Stuttgart/Dresden relativistic effective core potential was used for Pt
atom, whereas, 6–311+G(d) basis set [49–51] was used for CN
moieties. Workers [52,53] have used similar approach to perform
geometry optimizations obtaining better results. All calculations were
carried out using the Gaussian 16W software package [54]
utilizing the linear combination of atomic orbital–molecular orbital
(LCAO–MO) technique. In current investigation, all possible minimum
energy structures of Pt(CN)n complexes were
modelled. The structures were analyzed by using the GaussView 6 [55]
software.
EA values were obtained by calculating the energy difference between
optimized structures of neutral and anionic forms of
Pt(CN)n complexes. Highest occupied molecular
orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were
visualized by using the GaussView 6 [55] software. The HOMO and LUMO
are frontier orbitals which play an important role in determining the
chemical reactivity of complexes. Percentage (%) contribution by each
element to various orbitals of Pt(CN)n complexes
was determined by using the GaussSum 2.2 [56] program. The program
utilizes the output files generated by Gaussian 16W software
package [54] to determine the elemental percentage (%)
contributions in the orbitals. Parameters relevant for probing the
properties of supersalts and superacids corresponding to
Pt(CN)n complexes were also calculated byGaussian 16W software package [54] as discussed in following
section.