I’m a physics undergrad working with dynamic nuclear polarization of spin one targets ( in our labs case, deuterated propanediol). There is a particular mathematical technique to extract the polarization from the NMR signal which is invalid because deuterated propanediol has a quadrupole moment (between the O-D and C-D bonds). I have tried extensive googling to learn what a quadrupole moment is, but still don’t understand the concept. My background chem knowledge includes orgo 1-2, advanced organic, and physics wise I have a bit of electrodynamics. Is there any chance someone could explain what the quadrupole is and why the deuterated propanediol has one vs regular propanediol? Thanks!