The MIL DimimFeCl4 displays 3D antiferromagnetic ordering below 5.6K. The crystal structure at 10 K, solved by synchrotron XRPD, NPD and DFT calculations shows that it crystallizes in the space group P21. More recently diffraction experiments have shown an unexpected s-s transition from the low temperature phase, after heating from 2K and keeping it for several minutes between 180 and 220K. This new solid phase crystallizes in a similar structure with space group P21/c. Moreover, cooling the sample to 2K again gives a new magnetic structure with better defined long range magnetic ordering. The dynamics of larger imidazolium cations in non-magnetic RTIL¿s have been probed using quasi-elastic scattering. Results indicate a rich dynamical landscape in the ps-ns timescale, CH3 rotations, relaxations in the glassy state,... We expect similar motions in our shorter imidazolium system