1H-1,3-Benzazaphospholes react with M(CO)(5)(THF) (M = Cr, Mo, W) to give thermally and relatively air stable eta(1)-(1H-1,3-Benzazaphosphole-P)M(CO)(5) complexes. The H-1- and C-13-NMR-data are in accordance with the preservation of the phosphaaromatic pi-system of the ligand. The strong upfield P-31 coordination shift, particularly of the Mo and W complexes, forms a contrast to the downfield-shifts of phosphine-M(CO)(5) complexes and classifies benzazaphospholes as weak donor but efficient acceptor ligands. Nickelocene reacts as organometallic species with metalation of the NH-function. The resulting ambident 1,3-benzazaphospholide anions prefer a mu(2)-coordination of the eta(5)-CpNi-fragment at phosphorus to coordination at nitrogen or a eta(3)-heteroallyl-eta(5)-CpNi-semisandwich structure. This is shown by characteristic NMR data and the crystal structure analysis of a eta(5)-CpNi-benzazaphospholide. The latter is a P-bridging dimer with a planar Ni2P2 ring and trans-configuration of the two planar heterocyclic phosphido ligands arranged perpendicular to the four-membered ring.
1H-1,3-Benzazaphospholes react with M(CO)(5)(THF) (M = Cr, Mo, W) to give thermally and relatively air stable eta(1)-(1H-1,3-Benzazaphosphole-P)M(CO)(5) complexes. The H-1- and C-13-NMR-data are in accordance with the preservation of the phosphaaromatic pi-system of the ligand. The strong upfield P-31 coordination shift, particularly of the Mo and W complexes, forms a contrast to the downfield-shifts of phosphine-M(CO)(5) complexes and classifies benzazaphospholes as weak donor but efficient acceptor ligands. Nickelocene reacts as organometallic species with metalation of the NH-function. The resulting ambident 1,3-benzazaphospholide anions prefer a mu(2)-coordination of the eta(5)-CpNi-fragment at phosphorus to coordination at nitrogen or a eta(3)-heteroallyl-eta(5)-CpNi-semisandwich structure. This is shown by characteristic NMR data and the crystal structure analysis of a eta(5)-CpNi-benzazaphospholide. The latter is a P-bridging dimer with a planar Ni2P2 ring and trans-configuration of the two planar heterocyclic phosphido ligands arranged perpendicular to the four-membered ring.