Large Pressure-Induced Red Shift of the Luminescence Band Originating from Nonstacked Square-Planar [Pt(SCN)₄]^2- in a Novel Trimetallic Complex

Luminescence of the novel trimetallic complex {Pt(SCN)₂[(μ-SCN)Mn(NCS)(bipy)₂]₂} originates from a d−d transition of the square-planar [Pt(SCN)₄]^2- moiety. The band maximum shows a red shift of −99 cm^-1 kbar^-1 under external pressure up to 32 kbar at room temperature. This red shift is comparable to values for crystals where Pt−Pt interaction between stacked complexes is enhanced by pressure, but the crystal structure for the trimetallic complex shows that no metal−metal interaction can occur.