Synthese und Kristallstruktur von Bis[1,5-ditolylpentaazadienido-thallium(I)] und Bis[1,3-diphenyltriazenido-thallium(I)]/Synthesis and Crystal Structure of Bis[1,5-Ditolylpentaazadienido-thallium(I)] and Bis[ 1,3-diphenyltriazenido-thallium(I)]
The reaction of TlNO3 with 1,5-ditolylpentaazadiene in aqueous ammonia yields red [Tl(TolNNNNNTol)]2, which crystallizes in the monoclinic space group C2/c with the lattice constants a = 3322.9, b = 847.6, c = 1107.9 pm, β = 105.93°, Z = 4. The structure consists of dimeric molecules, in which two separate pentaazadienido chains and two T1 atom s are so arranged as to form trigonal pyramids, TlN3, with an average Tl-N distance of 274 pm. The N -N distances in the N5 chain are equal within the standard deviations, indicating a high ionic character for the Tl -N bonds. Intermolecular interactions link the dimers into infinite chains. Each Tl atom , already coordinated by three nitrogen atoms, is additionally coordinated by two nitrogen atoms of one neighbouring complex and the aromatic tolyl ring of another ligand. The distance between Tl and the π-bonded tolyl ring is 333 pm, comparable with values of other Tl arene complexes. The reaction of TlNO3 with 1,3-diphenyltriazene in the presence of NaOH yields red [Tl(PhNNNPh)]2, which crystallizes in the monoclinic space group P21/n with the lattice constants a = 1040.6, b = 636.7, c = 1763.5 pm, β = 96.98°, Z = 2. The structure consists of centrosymmetric dimeric molecules. The 1,3-diphenyltriazenide anion acts as an unsymmetrical bidentate chelating ligand for each Tl atom. The Tl-N distances (Tl-N1 = 261, Tl -N3 = 277 pm) are significantly different. N1 is additionally bonded to the Tl atom of the neighbouring monomer. The dimeric complexes form a planar, four-membered Tl2N2 ring in the form of a slightly distorted square. π-Interactions between Tl and a phenyl ring of a neighbouring complex link the dimers to form infinite chains with a Tl-phenyl distance of 327 pm.