Towards thermochromic and thermoresponsive near-infrared (NIR) luminescent molecular materials through the modulation of inter- and/or intramolecular Pt•••Pt and π-π interactions

A series of mononuclear and dinuclear alkynylplatinum(II) terpyridyl complexes has been found to show inter- and/or intramolecular aggregation in fluid solution state at low temperature or even at room temperature. Drastic colour changes and near infra-red (NIR) emission enhancement as well as broad and poorly resolved resonance signals in the H-1 NMR spectra were observed. Such aggregation processes have been probed by H-1 NMR, electronic absorption and emission spectroscopy.