 Trisamidomolybdenum(VI) alkylidyne complexes catalyze alkyne metathesis.By replacing a tungsten alkylidyne by a tungsten nitride and introducing a nitrile Nitrile-Alkyne Cross-Metathesis or NACM couples two nitrile groups together to a new alkyne.Nitrogen is collected by use of a sacrificial alkyne (elemental N2 is not formed)