The decomposition of the Pd-aryl complex (NBu4) 2 [Pd2 (μ-Br) 2Br2 (C6F5) 2](1) to the reduction product C6F5H was checked in different solvents and conditions. 1 is not stable in N-alkyl amides (DMF, NMP, DMA), cyclohexanone, and diethers (1, 4-dioxane, DME) at high temperatures (above 80° C). Other solvents such as nitriles, THF, water, or toluene are safe, and no significant decomposition occurs. The solvent is the source of hydrogen, and the ...