Molecular structure of 1,1',6,6'-tetraaza-7,7'-bi(bicyclo[4.1.0]heptane) in gas, solid and solution phases: GED, XRD and NMR data combined with quantum chemical calculations

The equilibrium molecular structure of 1,1',6,6'-tetraaza-7,7'-bi(bicyclo[4.1.0]heptane) in the gas phase has been determined from the data of the gas phase electron diffraction method using quantum chemical calculations up to the RI-MP2/def2-QZVPP level of theory. Structure studies were also carried out in $\mathrm{CDCl_3}$ solution using 1D and 2D $\mathrm{^{1}H}$ and $\mathrm{^{13}C}$ NMR spectroscopy and in the solid state using X-ray diffraction analysis. In the gas phase, three conformers of the molecule have been identified, while only one conformer is present in the $\mathrm{CDCl_3}$ solution and in the solid state, in which the substance crystallizes in space group $P\overline{1}$.