Multiply "trapped" 3 [trans-Pt(PR 3 ) 2 (C[triple bond, length as m-dash]CC 6 H 4 X) 2 ]* conformers in rigid media.

The complexes (R = Me, Et, Bu; X = H, SMe) exhibit well-defined multi-exponential emissions (2-4 components) in the solid state at 77 and 298 K and in 2MeTHF glasses at 77 K due to multiple frozen conformers exhibiting variable dihedral angles formed by the PtP2 C2 and C6 H4 planes. The demonstration was made using X-ray crystallography at various temperatures where different sites are present in the samples, and using geometry optimization (DFT computations) where various stable conformers are noted.