Influence of arene dissociation and phosphine coordination on the catalytic activity of [RuCl(κ2-triphos)(p-cymene)]PF6

► The isolation of rare examples of partially coordinated triphos complexes. ► The low activity of [RuCl(ê2-triphos)(p-cymene)]PF6 in hydrogenation reactions. ► The determination of arene binding strengths by thermolysis reactions. ► Insights into the mechanisms of arene displacement in DMSO. ► Rationalisation of the low catalytic activity of [RuCl(κ2-triphos)(p-cymene)]PF6.