Molecular structure of gaseous 1,1',2,2'-tetramethyl-3,3'-bidiaziridine, established by electron diffraction and quantum chemical calculations

The equilibrium geometry of the 1,1',2,2'-tetramethyl-3,3'‑bidiaziridine (TMBDA) molecule in the gas phase was determined using the gas-phase electron diffraction method in combination with quantum chemical calculations up to the allelectron RI-MP2/def2-QZVPP level of theory. It was confirmed that the TMBDA conformer with C2 symmetry dominates in the gas phase. Quantum chemical simulations of the crystal packing of TMBDA showed that the racemic form has lower lattice energy than the meso-form, which is consistent with the experimental ratio in the synthesized product.