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.

Correction to "Substrate Dynamics Contribute to Enzymatic Specificity in Human and Bacterial Methionine Adenosyltransferases".

[This corrects the article DOI: 10.1021/jacsau.1c00464.

Substrate Dynamics Contribute to Enzymatic Specificity in Human and Bacterial Methionine Adenosyltransferases.

Protein conformational changes can facilitate the binding of noncognate substrates and underlying promiscuous activities. However, the contribution of substrate conformational dynamics to this process is comparatively poorly understood. Here, we analyze human (hMAT2A) and (eMAT) methionine adenosyltransferases that have identical active sites but different substrate specificity.

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.