Antiprotozoal Pt(II) Complexes as Luminophores Bearing Monodentate P/As/Sb-Based Donors: An X-ray Diffractometric, Photoluminescence, and 121Sb-Mössbauer Spectroscopic Study with TD-DFT-Guided Interpretation and Predictive Extrapolation toward Bi

• DOI: 10.1021/acs.inorgchem.3c02727
• Publication Date: 2024-05-23T13:05:54Z
• Authors: Stefan Buss; Lukas Ketter; Dana Brünink; Dominik Schwab; Steffen Klenner; Alexander Hepp; Jutta Kösters; Thomas J. Schmidt; Rainer Pöttgen; Nikos L. Doltsinis; Cristian A. Stras...

In this study, it is demonstrated that the radiative rate constant of phosphorescent metal complexes can be substantially enhanced using monodentate ancillary ligands containing heavy donor atoms. Thus, chlorido coligand from a Pt(II) complex bearing monoanionic tridentate C^N*N luminophore ([PtLCl]) was replaced by triphenylphosphane (PPh3) and its heavier pnictogen congeners (i.e., PnPh3 to yield [PtL(PnPh3)]). Due high tridentate-ligand-centered character excited states, P-related rather low while showing significant boost upon replacement P As- Sb-based units. The syntheses three PPh3, AsPh3, SbPh3 were completed unambiguous characterization clean products exact mass spectrometry, X-ray diffractometry, bidimensional NMR, 121Sb-Mössbauer spectroscopy (for [PtL(SbPh3)]) as well steady state time-resolved photoluminescence spectroscopies. Hence, shown hybridization defects Vth main-group atoms overcome complexation with Pt center. Notably, enhancement constants mediated coligands achieved without significantly influencing states. A rationalization results TD-DFT. Even though Bi-based homologue not accessible due phenylation side reactions, experimental data allowed reasonable extrapolation structural features whereas properties related Bi-species phosphorescence predicted theory. showed an interesting antiprotozoal activity, which unexpectedly notorious for P-containing complex. This work could pave road toward new efficient materials optoelectronics novel antiparasitic drugs.