The diprotonated 2,2-(propane-1,3-diyl)bis(1,1,3,3-tetramethylguanidinium) cation: packing and conformational changes.

Subject to packing with different anions, the title cation undergoes various conformational changes with significantly different N-C-C-C torsion angles, as well as different angles between the NCN2 guanidine planes. The 2,2-(propane-1,3-diyl)bis(1,1,3,3-tetramethylguanidinium) salts reported here, viz. the dibromide, C13H32N6(2+).2Br-, the tetraphenylborate chloride, C13H32N62+.C24H20B-.Cl-, the tetrachloromercurate, (C13H32N6)[HgCl4], and the bis(trifluoromethanesulfonate), C13H32N6(2+).2CF3SO3-, are dominated by strong intermolecular N-H...X hydrogen bonds, which form different packing patterns.