Side‐On Bonded Beryllium Dinitrogen Complexes

The preparation and spectroscopic identification of the complexes NNBe(η(2)‐N(2)) and (NN)(2)Be(η(2)‐N(2)) and the energetically higher lying isomers Be(NN)(2) and Be(NN)(3) are reported. NNBe(η(2)‐N(2)) and (NN)(2)Be(η(2)‐N(2)) are the first examples of covalently side‐on bonded N(2) adducts of a main‐group element. The analysis of the electronic structure using modern methods of quantum chemistry suggests that NNBe(η(2)‐N(2)) and (NN)(2)Be(η(2)‐N(2)) should be classified as π complexes rather than metalladiazirines.