  Efficient polarization of organic molecules is of extraordinary relevance
when performing nuclear magnetic resonance (NMR) and imaging. Commercially
available routes to dynamical nuclear polarization (DNP) work at extremely
low-temperatures, thus bringing the molecules out of their ambient thermal
conditions and relying on the solidification of organic samples. In this work
we investigate polarization transfer from optically-pumped nitrogen vacancy
centers in diamond to external molecules at room temperature. This polarization
transfer is described by both an extensive analytical analysis and numerical
simulations based on spin bath bosonization and is supported by experimental
data in excellent agreement. These results set the route to hyperpolarization
of diffusive molecules in different scenarios and consequently, due to
increased signal, to high-resolution NMR.
