Would you expect a dipole moment determined in solution to be different from that in an isolated molecule? If so, why?
I've actually been investigating this in my comp chem coursework. A large dielectric can support more charge separation and therefore stronger dipoles, but the effect diminishes. Going from an $\epsilon$ of 2 (cyclohexane) to 9 (DCM) gives a much bigger change in dipole than going from 9 to 80+ (water).