Catalyst has been called as molecular machin Recent investigations have reported that not only enzyme acts as molecular machine but also the common catalysts own the similar functions The classical example is the metal cyclopentadiene(环戊二烯) complex which was used as the catalyst in olefin polymerization10 Catalyst has been called as molecular machine ❖ Recent investigations have reported that not only enzyme acts as molecular machine but also the common catalysts own the similar functions. ❖ The classical example is the metal cyclopentadiene (环戊二烯) complex which was used as the catalyst in olefin polymerization