A straightforward synthesis of a new hybrid scorpionate ligand [(allyl)(2)B-(CH2PPh2)(Pz)](-) ([A(2)BPN](-)) is reported. Coordination to rhodium resulted in squareplanar complexes [Rh(kappa(2)-A(2)BPN)(L)(L')] [L = L' = 1/2cod (1,5-cyclooctadiene), (CNBu)-Bu-t, CO (6); L = CO, L' = NH3, pyridine, PPh3, PMe3] for which spectroscopic data and the molecular structure of [Rh(kappa(2)-A(2)BPN)(CO)PPh3] (11) indicate the ligand to be kappa N,kappa P-bound to rhodium with two dangling free ally' groups. Studies in solution point out that the six-membered Rh-N-N-B-C-P rnetallacycle undergoes a fast inversion, in all of them. The bis(carbonyl) complex 6 easily loses a CO group to give [{Rh(A(2)BPN)(CO)}(2)], a dinudear compound in which two mononuclear subunits are brought together by two bridging allyl groups. Coordination to iridium is dominated by a tripodal kappa N,KP,eta(2)-C=C binding mode in the TBPY-5 complexes [Ir(kappa(3)-A(2)BPN)(L)(L')] [L = L' = 1/2cod (3), (CNBu)-Bu-t (5), CO (7); L = CO, L' = PPh3 (13), PMe3 (14), H2C=CH2, (17), MeO2CC CCO2Me (dmad, 18)], as confirmed by the single-crystal structure determination of complexes 3 and 18. A fast exchange between the two allyl arms is observed for complexes having L = L' (3, 5, and 7), while those having CO and L ligands (14, 17, and 18) were found to be nonfluxional species. An exception is complex 13, which establishes an equilibrium with the SP-4 configuration. Protonation reactions on complexes 13 and 14 with HCI yielded the hydride complex [Ir(kappa(2)-A(2)BPN)(CO)(Cl)(H)PPh3] (15) and the C-alkyl compound [Ir{kappa(3)-(allyl)B(CH2CHCH3)(CH2PPh2)-(Pz)}(Cl)(CO)PMe3] (16), respectively. The bis(isocyanide) complex 5 reacts with dmad to form [Ir(kappa(2)-A(2)BPN)-((CNBu)-Bu-t)(2)(dmad)]. On the whole, the electronic density provided to the metal by the [A(2)BPN](-) ligand is very sensitive to the coordination mode. The basicity of the new ligand is similar to that of the Tpme2 ligand in the kappa N,kappa P mode but comparable to Tp if coordinated in the kappa N,kappa P,eta(2)-C=C mode.