Phosphorescent Modulation of Metallophilic Clusters and Recognition of Solvents through a Flexible Host-Guest Assembly: A Theoretical Investigation.

摘要: MP2 (Second order approximation of Moller–Plesset perturbation theory) and DFT/TD-DFT (Density functional theory/Time-dependent_density_functional_theory) investigations have been performed on metallophilic nanomaterials host clusters [Au(NHC)2]+⋅⋅⋅[M(CN)2]−⋅⋅⋅[Au(NHC)2]+ (NHC = N-heterocyclic carbene, M Au, Ag) with high phosphorescence. The phosphorescence quantum yield in the experiments was evidenced by their μS1/ΔES1−T1 values ( μ S 1 : S0 → S1 transition dipole, ∆ E − T splitting energy between lowest-lying singlet triplet excited state T1 states). systematic variation guest solvents (S1: CH3OH, S2: CH3CH2OH, S3: H2O) are employed not only to illuminate effect interaction but also as probes investigate recognized capacity hosts. simulations revealed that interactions mainly electrostatic guests can subtly modulate geometries, especially Au⋅⋅⋅M distances hosts through mutual hydrogen bond interactions. spectra predicted be blue-shifted under polar solvent excitation from HOMO (highest occupied molecular orbital) LUMO (lowest unoccupied found responsible for 3MLCT (triplet metal-to-ligand charge transfer) characters host-guest complexes. results investigation introduced clues design promising blue-emitting phosphorescent materials.