5 Heteronuclear Correlation Spectroscopy H.C-COSY We will generally discuss heteronuclear correlation spectroscopy for x =C(in natura abundance!), since this is by far the most widely used application. However, all this can also be applied to other heteronuclear spins, like 3P, 5N, 1%F,etc In the heteronuclear case, there are some important differences that allow to