A time-dependent density functional theory study on the effect of electronic excited-state hydrogen bonding on luminescent MOFs.

We have investigated a new silver-based luminescent metal–organic framework (MOF) using density functional theory and time-dependent density functional theory methods. We theoretically demonstrated that the H⋯O hydrogen bond is strengthened and the Ag–O coordination bond is shortened significantly due to strengthening of the hydrogen bond in the S1 state. When the hydrogen bond is formed, the mechanism of luminescence changes from a ligand-to-metal charge transfer (LMCT) coupled with intraligand charge transfer (LLCT) to LMCT, and the luminescence is found to be enhanced.