The first example of a Pt...Pt interaction in platinum(ii) complexes bearing bulky tri-tert-butyl-2,2':6',2''-terpyridine pendants via conformational control of the calix[4]arene moiety.

An unprecedented short Pt...Pt contact between sterically bulky Pt((t)Bu(3)trpy) alkynyl moieties has been observed in the X-ray crystal structure of a dinuclear platinum(ii) complex bridged by a diethynylcalix[4]arene derivative; the complex in its crystalline state showed a red shift in the emission maxima at 298 K and 77 K relative to its powder form, which has been attributed to the presence of a metal-metal interaction in the crystal lattice.