NIR-laser-induced selective rotamerization of hydroxy conformers of cytosine

Abstract

The relative populations of two amino-hydroxy conformers of cytosine, differing in rotation of the OH group by ∼180°, were selectively and repeatedly manipulated with narrowband, near-infrared laser light. For cytosine monomers isolated in a low-temperature Ar matrix, laser irradiations at 7013 cm⁻¹ and at 7034 cm⁻¹ were found to induce effective transformations of the two conformers into each other.