Parahydrogen-induced polarization with a metal-free P-P biradicaloid

Metal-free H-2 activations are unusual but interesting for catalytic transformations, particularly in parahydrogen-based nuclear spin hyperpolarization techniques. We demonstrate that metal-free singlet phosphorus biradicaloid, [P(mu-NTer)](2), provides pronounced H-1 and P-31 hyperpolarization while activating the parahydrogen molecules. A brief analysis of the resulting NMR signals and the important kinetic parameters are presented.