At Adolf Baeyer's laboratory at the University of Munich, Gomberg worked closely with Johannes Thiele, whose partial valence theory explained organic compound reactivity by assigning partial bonds to carbons in chains with alternating single and double bonds. Earlier, Baeyer had succeeded in synthesizing organic compounds with August Kekulé, but not tetraphenylmethane. Several prominent chemists, among them Victor Meyer, had also failed in their attempts to synthesize tetraphenylmethane. They concluded it was inherently unstable.

At the University of Heidelberg, where he worked with Meyer, Gomberg took a different approach based on Thiele's work. He succeeded where others had failed and obtained a tiny amount of tetraphenylmethane.

Gomberg returned to Michigan, where he improved the yield slightly. He then tried to produce the next fully phenylated hydrocarbon-hexaphenylethane — by reacting triphenylmethyl halides with sodium in benzene. When this failed, he repeated the experiment using silver instead of sodium. He obtained a white crystalline powder that reacted with oxygen in the air.

To avoid this oxidation, Gomberg reacted triphenylmethyl chloride and zinc in an atmosphere of carbon dioxide. Sometimes, he allowed the experiment to run for weeks in a special airtight apparatus he had constructed. The reaction produced a thick, dark yellow syrup.

Gomberg removed the benzene solvent at reduced pressure, leaving behind a white solid of unexpectedly high reactivity. It oxidized rapidly in the air and reacted readily with halogens, including iodine. These properties were not what Gomberg expected from hexaphenylethane. "The experimental evidence ... forces me to the conclusion that we have to deal here with a free radical, triphenylmethyl," he wrote in his published findings. "On this assumption alone do the results described above become intelligible and receive an adequate explanation. ... The radical so formed is apparently stable, for it can be kept both in solution and in the dry crystalline state for weeks."

Gomberg published his findings in 1900 in the Journal of the American Chemical Society and in Germany's Berichte der Deutschen Chemischen Gesellschaft. Publishing simultaneously in English and German was a common practice at the time among U.S. scientists with links to Germany. It was also common to designate oneself the proprieter of a new field, as Gomberg did in the conclusion of his paper: "This work will be continued and I wish to reserve the field for myself."

Other chemists greeted Gomberg's discovery with skepticism. Most remained convinced that carbon must be tetravalent — understandable given that the explanation, electronic bonding, would not be articulated until years later by scientists such as G.N. Lewis, Walter Kossel and Irving Langmuir.