T-Shaped Palladium and Platinum {MNO} 10 Nitrosyl Complexes.

The synthesis and characterization of a homologous series of T-shaped {MNO} 10 nitrosyl complexes of the form [M(PR 3 ) 2 (NO)] + (M = Pd, Pt; R = t Bu, Ad) are reported. These diamagnetic nitrosyls are obtained from monovalent or zerovalent precursors by treatment with NO and NO + , respectively, and are notable for distinctly bent M-NO angles of ∼123° in the solid state. Adoption of this coordination mode in solution is also supported by the analysis of isotopically enriched samples by 15 N NMR spectroscopy. Effective oxidation states of M 0 /NO + are calculated, and metal-nitrosyl bonding has been interrogated using DFT-based energy decomposition analysis techniques. While a linear nitrosyl coordination mode was found to be electronically preferred, the M-NO and P-M-P angles are inversely correlated to the extent that binding in this manner is prevented by steric repulsion between the bulky ancillary phosphine ligands.