Stacking and Solvent Effects on the Electronic and Optical Properties of Gold and Mercury Acetylide Aggregations: A Theoretical Study

Abstract

The effects of various packing styles, solvents, and substituents on the electronic structures of gold(I) and mercury(II) acetylides are investigated by using the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). In comparison with the second-order Moeller−Plesset (MP2) and coupled-cluster (CCSD(T)) results, most of the hybrid GGA and hybrid meta GGA (among the studied 36 DFT functionals) can give reasonable predictions on binding energies in a dimer. A series of packing aggregates extended along intermolecular Au···Au and π−π (between aryl ligands) contacting directions are employed to illustrate the stacking dependence of the low-lying vertical excitation energies. The lowest excitation energy undergoes little change from the Au···Au linked dimer to higher oligomers. A polarized continuum model (PCM) study is carried out on a series of substituted gold and mercury acetylide derivatives in several solutions. The lowest vertical excitation energies exhibit a blue sh...