Carbon-carbon bond formation and cleavage at redox active bis(pyridylimino)isoindole (BPI) germylene compounds.

Redox-active ligands provide alternative reaction pathways by facilitating redox events. Among these, tridentate bis(piridylimino)isoindole (BPI) fragments offer great potential, though their redox-active behaviour remains largely underdeveloped. We describe herein a family of BPI germanium(II) complexes and the study of their redox properties.

Alternative Conceptual Approach to the Design of Bifunctional Catalysts: An Osmium Germylene System for the Dehydrogenation of Formic Acid.

The reaction of the hexahydride OsH(PPr) with a P,Ge,P-germylene-diphosphine affords an osmium tetrahydride derivative bearing a Ge,P-chelate, which arises from the hydrogenolysis of a P-C(sp) bond. This Os(IV)-Ge(II) compound is a pioneering example of a bifunctional catalyst based on the coordination of a σ-donor acid, which is active in the dehydrogenation of formic acid to H and CO. The kinetics of the dehydrogenation, the characterization of the resting state of the catalysis, and DFT calculations point out that the hydrogen formation (the fast stage) exclusively occurs on the coordination sphere of the basic metal center, whereas both the metal center and the σ-donor Lewis acid cooperatively participate in the CO release (the rate-determining step).

Preparation and Degradation of Rhodium and Iridium Diolefin Catalysts for the Acceptorless and Base-Free Dehydrogenation of Secondary Alcohols.

Rhodium and iridium diolefin catalysts for the acceptorless and base-free dehydrogenation of secondary alcohols have been prepared, and their degradation has been investigated, during the study of the reactivity of the dimers [M(μ-Cl)(η-CH)] (M = Rh (), Ir ()) and [M(μ-OH)(η-CH)] (M = Rh (), Ir ()) with 1,3-bis(6'-methyl-2'-pyridylimino)isoindoline (HBMePHI). Complex reacts with HBMePHI, in dichloromethane, to afford equilibrium mixtures of , the mononuclear derivative RhCl(η-CH){κ- -(HBMePHI)} (), and the binuclear species [RhCl(η-CH)]{μ- , -(HBMePHI)} (). Under the same conditions, complex affords the iridium counterparts IrCl(η-CH){κ- -(HBMePHI)} () and [IrCl(η-CH)]{μ- , -(HBMePHI)} ().

Synthesis and structural characterization of homochiral coordination polymers with imidazole-based monocarboxylate ligands.

Chiral Na[(S)-L] (R = Me, 1a; Pr, 1b; CHPr, 1c, and (S)-Bu, 1d) and Na[(R)-L] (R = Me, 1a') compounds were synthesised following standard procedures. New compounds 1d and 1a' were analytically and spectroscopically characterised. 1a and 1c were structurally identified by single-crystal X-ray diffraction methods as homochiral 2D coordination polymers, {Na(HO)[(S)-L]} and {Na[(S)-L]}, respectively.

Synthesis and structural characterization of homochiral 2D coordination polymers of zinc and copper with conformationally flexible ditopic imidazolium-based dicarboxylate ligands.

Different novel coordination polymers containing zinc, 1-4, and copper, 5-8, metals, connected via chiral imidazolium-based dicarboxylate ligands, [L], were isolated by reaction between zinc acetate or copper acetate and enantiomerically pure HL compounds. They were characterised and structurally identified by X-ray diffraction methods (single crystal and powder). These compounds are two-dimensional homochiral coordination polymers, [M(L)], in which the metal ions are coordinated by the two carboxylate groups of [L] anions in a general bridging monodentate μ-κ-O,κ-O fashion that afforded tetrahedral metal coordination environments for zinc, 1-4, and square planar for copper, 5-8, complexes.