Synthesis and structural characterization of multinuclear palladium(II) arylchalcogenolates compounds

The study of organopalladium compounds have been incresing in the last few years due to the diversity applications, as in catalisys,1 synthesis2 and material science3. The palladium arylchalcogenolate coordination chemistry has attracted great interest in a variety of applications, mainly in organometallic chemistry, as catalists in C-C coupling reations.4 Considering the great importance in this class of compounds, the purpose of this work is to present the synthesis and structural characterization of three new multinuclear palladium(II) arylchalcogenolates. The synthesis of these compounds were performed through oxidative addition reactions of [Pd(bipy)py2][(PF6)2] to (ArTe)2 ligands, diaryl ditelurides, where Ar = Ph, Mes, p-tBu-C6H4. Figure 1 shows the molecular structure of compounds 1-3, elucidated by single-crystal X-ray diffraction. The use of different (ArTe)2 led to 1-2 (dinuclear) and 3 (trinuclear) due to the basicity variation among arylchalcogenolate ligands generated in situ. The enhanced basicity of (MesTe)- is verified by central palladium in 3. Since [Pd(bipy)py2][(PF6)2] was used as palladium source, it was realized that (MesTe)- ligands substitute one bidentate bipy and two pyridyl ligands coordinated to palladium, leading a trinuclear compound. This fact did not happen to (PhTe)- and (p-tBu-C6H4Te)- in 1 and 2. For compounds 1-3 complementary analyzes were carried out, which corroborate with the structure elucidated by single crystal X-ray diffraction.