He lectured across the world on metal complexes of cyclopentadienyl, indenyl, arenes, olefins, and metal carbonyls. In the 1960s his group discovered a metal alkylidene and alkylidyne complexes, since referred to as Fischer carbenes and Fischer-carbynes. Overall he published about 450 journal articles and he trained many PhD and postdoctoral students, many of whom went on to noteworthy careers. Among his many foreign lectureships, he was Firestone Lecturer at the University of Wisconsin–Madison (1969), visiting professor at the University of Florida (1971), and Arthur D. Little visiting professor at the Massachusetts Institute of Technology (1973).