Utilising a Proton-Responsive 1,8-Naphthyridine Ligand for the Synthesis of Bimetallic Palladium and Platinum Complexes.

We present four proton-responsive palladium and platinum complexes, [MCl ( PONNHO)] (M=Pd, Pt; R= Pr, Bu) synthesised by complexation of PdCl or PtCl (COD) with the 1,8-naphthyridine ligand PONNHO. Deprotonation of [MCl ( PONNHO)] switches ligand coordination from mono- to dinucleating, offering a synthetic pathway to bimetallic Pd and Pt complexes [M Cl ( PONNO) ]. Two-electron reduction gives planar M -M complexes [M ( PONNO) ] (M=Pd, Pt) containing a metal-metal bond.

Oxidative Addition and β-Hydride Elimination by a Macrocyclic Dinickel Complex: Observing Bimetallic Elementary Reactions.

The dinickel(I) complex Ni ( PONNOPONNO), featuring a planar macrocyclic diphosphoranide ligand PONNOPONNO, offers a unique architectural platform for observing bimetallic elementary reactions. Oxidative addition reactions of alkyl halides produce dinickel(II) complexes of the type Ni (μ-R)(μ-X)( PONNOPONNO). However, when R=Et β-hydride elimination is observed to form a dinickel monohydride, with the rate dependent on the nature of X.

Bimetallic Nickel Complexes Supported by a Planar Macrocyclic Diphosphoranide Ligand.

Metal-metal cooperativity is emerging as an important strategy in catalysis. This requires appropriate ligand scaffolds that can support two metals in close proximity. Here we report nickel-promoted formation of a dinucleating planar macrocyclic ligand that can support bimetallic dinickel(II) and dinickel(I) complexes.

Metal coordination to a dimetallaoctatetrayne.

The reactions of the ditungstaoctatetrayne [(Tp*)(CO)W([triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash])W(CO)(Tp*)] with several metal complexes have been investigated. Addition of [Co(CO)] occurs across the internal C[triple bond, length as m-dash]C bonds, whereas [AuCl(SMe)] initially delivers 'AuCl' across the W[triple bond, length as m-dash]C carbyne bonds before undergoing further reaction to oxidise the tungsten and replace the carbonyl ligands with chloride in [(Tp*)ClW([triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash])WCl(Tp*)] with retention of the ditungstaoctatetrayne bridge. Reaction with [AuCl(PR)] (R = Ph, Cy) in the presence of AgPF prevents this oxidation and adds [AuPR] across the W[triple bond, length as m-dash]C bonds to give dicationic derivatives.