Multinuclear PtII Complexes: Why Three is Better Than Two to Enhance Photophysical Properties

Chemistry. 2020 Aug 26;26(48):11007-11012. doi: 10.1002/chem.202001510. Epub 2020 Jul 1.

Abstract

The self-assembly of platinum complexes is a well-documented process that leads to interesting changes of the photophysical and electrochemical behavior as well as to a change in reactivity of the complexes. However, it is still not clear how many metal units must interact in order to achieve the desired properties of a large assembly. This work aimed to clarify the role of the number of interacting PtII units leading to an enhancement of the spectroscopic properties and how to address inter- versus intramolecular processes. Therefore, a series of neutral multinuclear PtII complexes were synthesized and characterized, and their photophysical properties at different concentration were studied. Going from the monomer to dimers, the growth of a new emission band and the enhancement of the emission properties were observed. Upon increasing the platinum units up to three, the monomeric blue emission could not be detected anymore and a concentration independent bright-yellow/orange emission, due to the establishment of intramolecular metallophilic interactions, was observed.

Keywords: aggregation-induced emission; luminescence; metallophilic interactions; multinuclear; platinum.