Spectroscopic evidence on the acetonitrile cleavage at mild condition.

Among the present numerous chemical libraries, acetonitrile is the one of famous common organic solvents widely used in modern science and industry. Since it has been known as very stable and inert solvent, there has been little doubt on its catalytic decomposition to cyanide in mild condition. In this report, I provide new evidence on the catalytic decomposition of acetonitrile at conventional gold surfaces without any electrochemical treatment. Various surface enhanced Raman spectroscopic (SERS) measurements on high-purity acetonitrile reveal that the observed anomalous peak originates from the plasmonically cleaved cyanide group on SERS-active gold surface, which is also supported by the results of time of flight-secondary ion mass spectrometry (TOF-SIMS). This work sheds light on the plasmonic induced unprecedented reaction of the small chemical species that have been known intact.