Isolation of a (dinitrogen)tricopper(I) complex.

Reaction of a tris(β-diketimine) cyclophane, H3L, with benzyl potassium followed by [Cu(OTf)]2(C6H6) affords a tricopper(I) complex containing a bridging dinitrogen ligand. rRaman (νN-N = 1952 cm(-1)) and (15)N NMR (δ = 303.8 ppm) spectroscopy confirm the presence of the dinitrogen ligand. DFT calculations and QTAIM analysis indicate minimal metal-dinitrogen back-bonding with only one molecular orbital of significant N2(2pπ*) and Cu(3dπ)/Cu(3dσ) character (13.6% N, 70.9% Cu). ∇(2)ρ values for the Cu-N2 bond critical points are analogous to those for polar closed-shell/closed-shell interactions.