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Unique superhalogen properties of Pt(CN)n complexes (n = 1–6) have been investigated under the quantum chemical formalism. The study involves theoretical calculations for both neutral and anionic forms of Pt(CN)n using density functional theory (DFT) with the hybrid functional B3LYP. In order to improve the accuracy of calculations, 6–311+G(d) basis set was implemented for CN moieties, whereas SDD basis set supplemented with Stuttgart/Dresden relativistic effective core potential was used for Pt atom. Long-range electron correlations in the subject molecules have been accounted for by using Grimme's dispersion with the D3 damping function. HOMO-LUMO energy band gaps, vibrational frequencies, and dissociation energies of Pt(CN)n complexes have been calculated to investigate their relative stability as well as reactivity. Salt-forming capability of Pt(CN)n complexes has also been analyzed. Reliable low-cost investigations on superacidity properties of associated protonated species have been carried out keeping their industrial applications in mind. [ABSTRACT FROM AUTHOR]

Density functional theory calculations, using the B3LYP parameterisation, were performed to determine structures, vibrational frequencies, and binding energies for complexation of Ni+ and Ni2+ cations with benzene and naphthalene molecules and clusters. The calculations employed the Stuttgart basis set with ECP pseudo potentials for the Ni cations and basis sets of at least triple ζ plus polarisation, and diffuse quality for C and H. The effect of electron correlation on non-bonded interactions was accounted for by the Grimme GD3 dispersion correction. Counterpoise computations were made for BSSE. Comparison between experiment and theory provide fascinating new insight into the bonding for these prototypical organometallic (OM) complexes. These structures have a sandwich topology, indicating major structural reorganisations occuring when benzene or naphthalene interact with Ni cations. Adiabatic electron affinities and ionisation potentials agree well with experiment when available. Binding energies were also determined, providing insight into the stability of the complexes. The results presented here provide important information for future studies to address additional investigations of both problems of the electronic structure properties of these complexes, as well as the role of the polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium (ISM) and soot formation in combustion. The Ni+/Ni2+ + aromatic organometallic bonding is of the same order of stability as an aromatic C–H bond. Such bonding modifies the IR spectrum of the complexed aromatic molecules by enhancing the 3.3 μm feature and decreasing the C–H bands in the 11–12 μm range (γ C–H). Organometallic complexation reactions may contribute significantly to metal depletion in the ISM. [ABSTRACT FROM AUTHOR]