A study on the rules of ligands in highly efficient Ru-amide/AC catalysts for acetylene hydrochlorination

To explore the role of substituents on ligands on the modification of metal catalysts, a series of Ru-amide/AC catalysts are synthesized with various amide ligands derived from formamide and assessed for acetylene hydrochlorination. Activity evaluation reveals a rule that a hydrogen on formamide replaced by electron donor substituents could enhance the catalytic performance while electron withdrawing substituents have the opposite effect. Besides, substitution of a hydrogen on amino by phenyl is more favorable than that on carbon in the formamide molecule. Characterization and DFT simulation results ascribe the activity difference of Ru-Be/AC and Ru-Foli/AC to different positions of phenyl in benzamide and formanilide, which affects the electron cloud density around Ru, albeit the same E-R reaction mechanism. Finally, benzanilide with superior modification effect which searched by above results gives a strong evidence for the correction of these rules. This work provides a theoretical basis for the search of efficient ligands for acetylene hydrochlorination.