A three-dimensional metal–organic framework compound [NH2(CH3)2]2[Zn3(bpdc)4]·3DMF (1) shows two step dielectric relaxation and its guest-free framework (1′) possesses an ultra-low κ value of 1.80 (at 100 kHz, it is the lowest value for MOFs reported to date) over a wide temperature range and high thermal stability.
