Simon studied Chemistry at the University of Münster from 1960-1964. He worked on his doctoral thesis in the group of Harald Schäfer from 1964-1966 and finished his habilitation in 1971. In 1972, he was appointed as an associate professor at the University of Münster. Starting in 1974, he was a member of the Max-Planck Society and one of the directors at the Max Planck Institute for Solid State Research in Stuttgart. Since 1975, he was a honorary professor at the University of Stuttgart. Since 2010, he has been an emeritus.