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 1 H NMR spectra were observed. Such aggregation processes have been probed by 1 H NMR, electronic absorption and emission spectroscopy. Mono- and dinuclear alkynylplatinum( ii ) terpyridyl complexes show drastic colour changes and NIR emission enhancement due to aggregation upon a change in temperature.