Spectroscopic studies of cyclo-metallated Pt(lI) complexes: optical absorption and emission and the structure of single crystal [Pt(bpm)(CN) 2]·H 2O (bpm = 2,2′-bipyrimidine)

Abstract

The polarized optical absorption and emission spectra of single crystal [Pt(bpm)(CN) 2]·H 2O (bpm =2,2′-bipyrimidine) have been measured as functions of temperature (1.9 K⩽ T⩽295 K) and of homogeneous magnetic fields (0 ⩽ H⩽6 T). Analysis of the spectra shows that the inter-complex coupling is weak and that the emission at low temperatures originates mainly from two types of traps located energetically by Δv̄ ∼40 and ∼45 cm −1, respectively, below the triplet exciton band. The spectroscopic properties are discussed on the basis of the crystallographic data for [Pt(bpm)(CN) 2]·H 2O: monoclinic, space group P2 1/ c, a = 7.076(1), b = 8.999(2), c = 18.127(2) )Å, β = 99.84(1)°, V = 1137.29 Å 3, Z = 4, D x = 2.47 g cm −3. Anisotropic refinement (2743 reflexes I>; 2σ( I), 163 variables) resulted in R = 0.066, R w = 0.037, S = 0.78.