The first cyclopentadienylnickel amido complexes have been isolated and characterized as [(η-C5Me4R') Ni (μ-NHR)] 2 (R= Ph, p-tol, 2, 6-xyl, tBu; R'= Me, Et). These complexes are dimers in solution and in the solid state, as shown by the synthesis of mixed amido complexes, by NMR spectroscopy, and by crystallographic studies on cis-[CpEtNi (μ-NH (p- tol))] 2 (cis-1'), trans-[CpEtNi (μ-NH (2, 6-xylyl))] 2 (trans-3'), and cis-[CpEtNi (μ-NHtBu)] 2 ( ...