Palladiumdichloride (ferrocenylethynyl)phosphanes and their use in Pd-catalyzed Heck–Mizoroki- and Suzuki–Miyaura carbon–carbon cross-coupling reactions

A β-ketoiminato palladium(II) complex for palladium deposition

The ¦-ketoiminato complex [Pd(OAc)L] (3) can be synthesized by the reaction of bis(benzoylacetone)diethylenetriamine (1, = LH) with [Pd(OAc)2] (2). The structure of 3 in the solid state has been determined by single X-ray diffraction analysis. Complex 3 crystallizes as a dimer (3 2), which is formed by hydrogen bonds between NH and OOAc functionalities of two adjacent ligands. Each of the Pd atoms is complexed by one ON2 donor unit of the polydentate ligand L − and an acetate group. Pd–Pd interactions and hydrogen bond formation between a NH and the C=O acetate moiety lead to a [4 + 2] coordination at Pd. The non-coordinated part of L exists in its ¦-keto-enamine form. The thermal decomposition behavior of 3 2 was studied by TG (thermogravimetry) and TG-MS showing that 3 2 decomposes between 200 and 500°C independent of the applied atmosphere. Under oxygen PdO is produced, while under argon Pd is formed as confirmed by PXRD measurements. Complex 3 2 was applied as a spin-coating precursor (conc. 0.1 mol L−1, volume 1.5 mL, 3000 rpm, deposition time 6 min, heating rate 50 K min−1, holding time 60 min (Ar) and 120 min (air) at T = 800°C). The as-obtained samples are characterized by granulated particles of Pd/PdO on the substrate surface. EDX (energy-dispersive X-ray spectroscopy) and XPS (X-ray photoelectron spectroscopy) measurements confirmed the formation of Pd (Ar) or PdO (O2) with up to 12 mol% C impurity.

Alkynylbis(alkylidynyl)phosphines: {LnMC}2PCCR

Synthetic strategies are presented for the formation of alkynylbis(alkylidynyl)phosphines which represent promising building blocks for unsaturated 2- and 3-dimensional assemblies. Parent ethynyl derivatives provide a means for installing further donor functionalities, e.g., AsPh₂ as shown.

Redox-active phosphines: synthesis and crystal structures of palladium(II) complexes of a metallaphosphine in two different oxidation states

The redox-active metallaphosphine [Fe(dppe)(η(5)-C5Me5)(C≡C-PPh2)] reacts with [Pd(1,5-cod)Cl2] to give mono- and bis-phosphine coordinated palladium centres as a function of stoichiometry, and these complexes provide a stable redox-active platform which allows reversible one-electron {Fe(II)→Fe(III)(+)} oxidations within the palladium coordination sphere.

Metal-rich organometallics

The scope of organometallics has recently been expanded considerably, when researchers have started to employ these compounds in the context of materials chemistry. Traditionally, organometallic complexes have been and continue to be important tools for many (catalytic) chemical transformations. This perspective highlights how metal-rich organometallics, that is compounds with more than one type of metal, can play an important role in the advancement of new value-added functional materials.