M. Pilar del Río

Ligand-centred reactivity of bis(picolyl)amine iridium: Sequential deprotonation, oxidation and oxygenation of a "non-innocent" ligand

Treatment of [Ir(bpa)(cod)](+) complex [1](+) with a strong base (e.g., tBuO(-)) led to unexpected double deprotonation to form the anionic [Ir(bpa-2H)(cod)](-) species [3](-), via the mono-deprotonated neutral amido complex [Ir(bpa-H)(cod)] as an isolable intermediate. A certain degree of aromaticity of the obtained metal-chelate ring may explain the favourable double deprotonation. The rhodium analogue [4](-) was prepared in situ. The new species [M(bpa-2H)(cod)](-) (M = Rh, Ir) are best described as two-electron reduced analogues of the cationic imine complexes [M(I)(cod)(Py-CH(2)-N=CH-Py)](+). One-electron oxidation of [3](-) and [4](-) produced the ligand radical complexes [3](*) and [4](*). Oxygenation of [3](-) with O(2) gave the neutral carboxamido complex [Ir(cod)(py-CH(2)-N-CO-py)] via the ligand radical complex [3](*) as a detectable intermediate.

Deprotonation induced ligand-to-metal electron transfer: Synthesis of a mixed-valence Rh(-I,I) dinuclear compound and its reaction with dioxygen

Treatment of bis(2-picolyl)amine (bpa) with [{Rh(nbd)(mu-OMe)}2] leads to the unexpected and unique redox asymmetric dinuclear Rh-I,Rh+I complex [{Rh(nbd)}2(bpa-2H)] (2) with a pi-coordinating imine bound to a tetrahedral low valent rhodate(-I). Mono-oxygenation of the deprotonated bpa ligand in 2 by O2 leads to the mononuclear carboxamido complex [Rh(nbd)(bpam-H)] (3) (bpam = N-(2-picolyl)picolinamide). The second O atom of O2 ends up as a hydroxo fragment in [{Rh(nbd)(mu-OH)}2].

Developing synthetic approaches with non-innocent metalloligands: Easy access to Ir I/Pd 0 and Ir I/Pd 0/Ir I cores

Guilty as charged is the verdict for anionic Ir complex [Ir(bpa−2 H)(cod)]− in its reactions with PdII compounds. The net transfer of two electrons from the Ir complex to Pd allows easy preparation of di‐ and trinuclear π‐imine‐coordinated Pd0 compounds such as [{Ir(PyCH2NCHPy)(cod)}2Pd] (see picture; C white, Ir red, N blue, Pd yellow). bpa−2 H: doubly deprotonated form of N,N‐bis(2‐picolyl)amine (bpa); cod: 1,5‐cyclooctadiene.

Rhodium mediated C-H bond functionalisation leading to carboxylate derivatives.

Generous financial support from MICINN/FEDER (Project CTQ2008- 03860) and GA (Gobierno de Aragon, PM 36/2007) is gratefully acknowledged.

Connecting CC Bonds to Tetrairidium Chains

Funded by: MICINN/FEDER. Grant Number: CTQ2011-22516 and Gobierno de Aragon (GA)/FSE (E70).