Linear diammonium cations of general formula NH3(CH2)mNH3 2+ with even carbonchain lengths (m = 4, 8, 10, 12) form n = 1 2D lead-halide perovskites, while those with odd carbon chain length (m = 7) form 1D perovskitoid structures. Moreover, diammonium cations with fused aromatic rings only give rise to 2D MHPs when being able to tilt in order to form hydrogen bonds to the halides. In general, the tilting of diammonium cations seems to be of great importance, since aromatic cations, where the ammonium groups may have no degree of freedom, tend to form 1D perovskitoid motifs. This is the case for (4,4′-MDA)PbI4