Right before the final fight, we see Loki and Stark discussing the terms of the upcoming battle, bantering back and forth between who will win.
It is then that Loki gets the idea of turning Stark against his comrades like he did with Hawkeye, as well as a bunch of other S.H.I.E.L.D. agents at the beginning of the movie.
But, it doesn't work at all.
Is this because of Stark's Arc Reactor countering the Cosmic powers somehow, because Stark is incorruptible (which doesn't make much sense), or possibly because simply he was touching the Arc Reactor and not Stark's flesh?
Either way, is there an explanation of why this did not work on Tony?