On the Ambident Behaviour of Dicyanmethanidonitrite; Syntheses and Characterization of Complexes of the Type [M{N(O)C(CN)2}(PPh3)n] (M = CuI, AgI;n = 2, 3)

Abstract

Complexes of the type [M{N(O)C(CN)2}(PPh3)n] (M = CuI, AgI, n = 2, 3) were synthesized by metathesis of K[N(O)C(CN)2] and [M(NO3)(PPh3)n]. The complexes were characterized by 13C-, 31P-NMR and IR spectroscopy and elemental analyses. The crystal structures of [M{N(O)C(CN)2}(PPh3)2]2 (M = CuI, AgI) have been determined by X-ray diffraction. Depending on the metal atom in the complexes [M{N(O)C(CN)2}(PPh3)3] the ionic ligand is coordinated via the central nitrogen (copper) or the oxygen atom (silver). In addition the two copper and silver complexes [M{N(O)C(CN)2}(PPh3)2]2 are not isostructural but have quite different structures. For M = Cu the two copper atoms are doubly bridged by two NCCN sequences, forming an approximately planar Cu(NCCN)2Cu ring. On the other hand, in the homologous silver derivative the metal atoms are also doubly bridged, but by two NO groups, thus forming a planar six-membered ring.