Molocine was an element used by extremely advanced civilizations. The Federation was unable to shape it as of 2367. (Star Trek: The Prospect Chronicles: "The Burnt Child", "Starry, Starry Night")
In late 2366, an away team from the USS Worsaae discovered an artifact made of molocine on an archaeological expedition on Matanda. (Star Trek: The Prospect Chronicles: "The Burnt Child")
The planet Goffan IV was rich in molocine deposits. In 2367, the Federation and Jenchum Suzerainty brokered a deal whereby the USS Prospect would conduct a scientific mission to Goffan IV to adequately align sensors to accurately and adequately detect molocine. The Jenchum battle cruiser Alonia assisted in the process, bringing sensor technology ahead by leaps and bounds.
The Jenchum also shielded the Enikan testing area for a subspace weapon with molocine. When the weapon malfunctioned, the subspace anomaly it created was contained due to the molocine walls. (Star Trek: The Prospect Chronicles: "Starry, Starry Night")