Analysis of Near Infrared-Emitting Bimolecular Excited States in Platinum(II) Complexes with Simple Computational Tools

This work presents a simple computational methodology for analysing and predicting luminescence originating from bimolecular excited states, dimers and excimers, of platinum(II) complexes. Photoluminescence spectrum of said species resembles Gaussian distribution. Gaussian perfectly fits PL spectra in the region of interest from the onset to peak and given its simplicity serves as a perfect model for experimental data. Time-dependent density functional theory (TDDFT) methods provide computational data which are then correlated with the features of the experimental PL spectrum: peak and onset energy. Good linear correlation (r2 = 0.94) between experimental and computational data yields high precision predictions of PL spectra based on the simple computational model. A diverse selection of platinum(II) complexes used for calibration of the model guarantees generality. The study provides an insight into the structure of dimers/excimers of platinum complexes, suggesting that anti or head-to-tail configuration is preferred.