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

• Published in: Angewandte Chemie International Edition Vol. 63; no. 38; pp. e202405330 - n/a
• Main Authors: Willrett, Julie, Schmitt, Manuel, Zhuravlev, Vadim, Sellin, Malte, Malinowski, Przemysław J., Krossing, Ingo
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 16.09.2024
• Edition: International ed. in English
• Subjects: Cadmium; Copper; dinitrogen complex; Metathesis; Nitrogen compounds; Perfluorohexane; quantum chemical calculations; Quantum chemistry; Synthesis; Transition metals; weakly coordinating anion; quantum chemical calculations; copper; dinitrogen complex; weakly coordinating anion; metathesis
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202405330

We report the synthesis and full characterization of the copper dinitrogen complex [(η1‐N2)Cu{Al(ORF)4}] 2 (RF=C(CF3)3) prepared by a cascade metathesis reaction of Ag[Al(ORF)4] with CuI‐excess in iso‐perfluorohexane (i‐pfh) under N2 atmosphere. Title compound 2 features an extraordinarily high N2 stretching frequency at 2313/2314 cm−1 (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. Cascade Synthesis: The copper dinitrogen complex [(η1‐N2)Cu{Al(ORF)4}] (RF=C(CF3)3) with an unprecedentedly high N≡N stretching frequency of 2314 cm−1 and a positive charge of +0.10 residing on the terminal N atom is reported. Synthesis proceeded from Ag[Al(ORF)4] in a triple consecutive cascade reaction with CuI excess to obtain pure product without Ag+ contamination. [(η1‐N2)Cu{Al(ORF)4}] was fully characterized by NMR, vibrational spectroscopy, EDX, XRD and quantum chemical analyses.