The syntheses and characterization of series of new metallocene-bridged diphosphines and the structures of complexes of some of them with Pd(II) are reported. These complexes were examined as the catalysts in amination reactions of halogenoarenes and in the Suzuki reaction. The complexes based on ruthenocene (2) and osmocene (3) showed lower activities then the palladium complex with dppf in amination reactions and the same activities in the Suzuki reaction. New palladium complexes with the bidentate bulky and electron-rich ligands Fe(η 5-C5H4P(o-Pr i C6H4)2)2 (6) and Fe(η 5-C5H4P(o-MeOC6H4)2)2 (5) showed a very high catalytic activity in amination and Suzuki coupling of aryl bromides. A complex with ligand 6 was used in the amination of 4-bromotoluene by primary and secondary amines and showed excellent activity.

The thermodynamics of chloride dissociation from the 18e arene ruthenium iminophosphonamides [(η -arene)RuCl{(R'N) PR }] (1 a-d) [previously known with arene=C Me , R=Ph, R'=p-Tol (a); R=Et, R'=p-Tol (b); R=Ph, R'=Me (c); and new with arene=p-cymene, R=Ph, R'=p-Tol (d)] was assessed in both polar and apolar solvents by variable-temperature UV/Vis, NMR, and 2D EXSY H NMR methods, which highlighted the influence of the NPN ligand on the equilibrium parameters. The dissociation enthalpy ΔH decreases with increasing electron-donating ability of the N- and P-substituents (1 a, 1 d>1 b>1 c) and solvent polarity, and this results in exothermic spontaneous dissociation of 1 c in polar solvents. The coordination of neutral ligands (MeCN, pyridine, CO) to the corresponding 16e complexes [(η -arene)Ru{(R'N) PR }] PF (2 a-d) is reversible; the stability of the 2⋅L adducts depends on the π-accepting ability of L. Carbonylation of 2 a and 2 d resulted in rare examples of cationic arene ruthenium carbonyl complexes (3 a, 3 d), while the monocarbonyl adduct derived from 2 c reacts further with a second equivalent of CO with conversion to carbonyl-carbamoyl complex 3 c, in which one CO molecule is inserted into the Ru-N bond. The new complexes 1 d, 2 d, 3 a, 3 c, and 3 d were isolated and structurally characterized.

Novel half-sandwich 18ē and 16ē arene ruthenium iminophosphonamide complexes [(η-CMe)RuCl{(R'N)PR}] (3a-c) and [(η-CMe)Ru{(R'N)PR}](X) (4a-c) (a, R = Ph, R' = p-Tol; b, R = Et, R' = p-Tol; c, R = Ph, R' = Me. X = BF, PF or BAr) were synthesized. The elongated Ru-Cl bond in the 18ē complexes is shown to dissociate even in apolar solvents to form the corresponding 16ē cations, which can be readily isolated as salts with non-coordinating anions. The coordinatively unsaturated 16ē complexes are stable species due to efficient π-electron donation from the nitrogen atoms of the zwitterionic NPN-ligand. The ruthenium iminophosphonamides are moderately active in the ROMP polymerization of norbornene; the 16ē complexes 4a,b yield high molecular weight polymers (M∼ 300 × 10) with a narrow distribution M/M∼ 1.6, while the 18ē complexes 3a,b give polymers of lower molecular weight (M < 50 × 10) with a wider polydispersity index M/M∼ 2.5.

New aminoiminophosphoranate (κ2-(N,N)-(NC6H4 i-Pr-p)2PPh2, NPN) complexes (NPN)Pd(PPh3)Cl, (NPN)2Pd, (NPN)Pt(η2-C2H4)Cl, and (NPN)Pt(PPh3)Cl were prepared in high yields from anionic [NPN]Li and the corresponding transition metal chloride precursors. Reaction of (PhCN)2PdCl2 with aminoiminophosphorane [NPN]H afforded bis-imino complex Pd{[NPN]H}2Cl2 in 82% yield. X-ray structures of all palladium complexes were reported, and the specific weak interactions C−H···Pd were detected in the crystals of both (NPN)Pd(PPh3)Cl (intramolecular) and (NPN)2Pd (intermolecular). The topological analysis of electron density function ρ(r) within the AIM theory performed for (NPN)2Pd allowed us to analyze the peculiarities of the chemical bonding of the NPN ligand and to estimate the energy of the intermolecular C−H···Pd interaction as 0.8 kcal/mol. The plausible influence of these weak interactions on the bending of the PdNPN metallacycle was discussed.