  In 2016, we reported a single-ion magnet [Dy(bbpen)Br] with an energy barrier
over 1000 K. Here a dimeric [Dy2(mu-CO3)(bbpen)2(H2O)].H2O.CH3OH (1) and a
trimeric [Dy3(mu3-CO3)(bppen)3](CF3SO3).H2O (2) single-molecule magnets (SMMs)
were obtained through replacing the Br- anion with the carbonate bridge. Their
effective relaxation barriers at zero dc field are decrease to 51 K and 422 K,
respectively, which are consist with their structural modifications.
