Primary photophysical and photochemical processes for cerium ammonium nitrate (CAN) in acetonitrile.

Cerium ammonium nitrate (CAN) is an important photolytic source of NO radicals in aqueous nitric acid solutions and in acetonitrile. In this work we performed the study of primary photochemical processes for CAN in acetonitrile by means of ultrafast TA spectroscopy and quantum chemical calculations. Photoexcitation of CAN is followed by ultrafast (< 100 fs) intersystem crossing; the vibrationally cooled triplet state decays to pentacoordinated Ce(III) intermediate and NO radical with the characteristic time of ca.