Molecular and Crystal Structure of an Organoplatinum(II) Complex with Dipyrido[3,2-a : 2′,3′-c]phenazine (dppz)

The dimesitylplatinum(II) complex PtMes₂(dppz) (Mes = mesityl = 2,4,6-trimethylphenyl) crystallizes with one equivalent of toluene (C₄₃H₄₀N₄Pt, monoclinic, P2₁/c, Z = 4, a = 14.3551(14) Å, b = 15.8319(14) Å, c = 15.369(2) Å, β = 96.784(6)°). The (dppz)Pt(C1_Mes)₂ part of the molecule was found to be planar, the mesityl substituents adopting dihedral angles of 70.3° and 85.5° with that plane. The photoemissive and reversibly reducible and oxidizable complex molecules form pairs in the crystal with the planar phenazine π “tails” overlapping in graphite-like fashion at 3.427 Å distance. The results are discussed in comparision with a recently reported structure of PtCl₂(dppz).