Synthesis and Characterization of a Copper Dinitrogen Complex Supported by a Weakly Coordinating Anion.

We report the synthesis and full characterization of the copper dinitrogen complex [(η-N)Cu{Al(OR)}] 2 (R=C(CF)) prepared by a cascade metathesis reaction of Ag[Al(OR)] with CuI-excess in iso-perfluorohexane (i-pfh) under N atmosphere. Title compound 2 features an extraordinarily high N stretching frequency at 2313/2314 cm (IR/Raman) and was characterized by single-crystal and powder X-ray diffractometry. Quantum chemical charge displacement analysis based on natural orbitals of chemical valence (CD-NOCV) indicates that the copper-dinitrogen interaction is still governed by weak π-backdonation, but is significantly reduced compared to all literature-known transition metal dinitrogen complexes.