Anti and gauche conformers of an inorganic butane analogue, NH3BH2NH2BH3

The crystal structures of an inorganic butane analogue, NH3BH2NH2BH3 (DDAB), were determined using single crystal X-ray diffraction, revealing both anti and gauche conformations. The anti conformation is stabilized by intermolecular dihydrogen bonds in the crystal whereas two gauche conformations of DDAB observed in its 18-crown-6 adducts are stabilized by an intramolecular dihydrogen bond. The two gauche conformations show rotational isomerization but whether they are a pair of enantiomers is yet to be defined.