Coinage Metal Complexes of Bis(quinoline-2-ylmethyl)phenylphosphine-Simple Reactions Can Lead to Unprecedented Results.

The different coordination behavior of the flexible yet sterically demanding, hemilabile P,N ligand bis(quinoline-2-ylmethyl)phenylphosphine (bqmpp) towards selected Cu , Ag and Au species is described. The resulting X-ray crystal structures reveal interesting coordination geometries. With [Cu(MeCN) ]BF , compound 1 Cu (bqmpp) is obtained, wherein the copper(I) atoms display a distorted square planar and square pyramidal geometry. The steric demand and π-stacking of the ligand allow for a short Cu⋅⋅⋅Cu distance (2.588(9) Å). Cu complex 2 [Cu Cl (bqmpp) ]BF contains a rarely observed Cu Cl cluster, probably enabled by dichloromethane as the chloride source. In the cluster, even shorter Cu⋅⋅⋅Cu distances (2.447(1) Å) are present. The reaction of Ag[SbF ] with the ligand leads to a dinuclear compound (3) in solution as confirmed by P{ H} NMR spectroscopy. During crystallization, instead of the expected phosphine complex 3, a tris(quinoline-2-ylmethyl)bisphenyl-phosphine (tqmbp) compound Ag (tqmbp) 4 is formed by elimination of quinaldine. The Au(I) compound [Au (bqmpp) ]PF (5) is prepared as expected and shows a linear arrangement of two phosphine ligands around Au .