Photochemically Induced Dynamic Nuclear Polarization of Heteronuclear Singlet Order

Photochemically induced dynamic nuclear polarization (photo-CIDNP) is a method to hyperpolarize spins using light. In most cases, CIDNP experiments are performed in high magnetic fields and the sample irradiated by light inside resonance (NMR) spectrometer. Here we demonstrate photo-CIDNP hyperpolarization generated Earth’s field under zero- ultralow-field (ZULF) conditions. Irradiating containing tetraphenylporphyrin para-benzoquinone for several seconds with light-emitting diodes produces strong of 1H 13C spins, enhancing NMR signals more than 200 times. The hyperpolarized spin states at ZULF different. latter case, state corresponds singlet order between scalar-coupled 1H–13C spins. This has longer lifetime field. simple cost-efficient should be applicable many molecular systems known exhibit photo-CIDNP, including amino acids nucleotides.