Premium
Ligand Protonation Triggers H 2 Release from a Dinickel Dihydride Complex to Give a Doubly “T”‐Shaped Dinickel(I) Metallodiradical
Author(s) -
Duan PengCheng,
Schulz Roland Alexander,
Römer Anton,
Van Kuiken Benjamin E.,
Dechert Sebastian,
Demeshko Serhiy,
Cutsail George E.,
DeBeer Serena,
Mata Ricardo A.,
Meyer Franc
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202011494
Subject(s) - bimetallic strip , protonation , chemistry , ligand (biochemistry) , pincer movement , crystallography , metal , substrate (aquarium) , stereochemistry , catalysis , ion , biochemistry , organic chemistry , receptor , oceanography , geology
The dinickel(II) dihydride complex ( 1 K ) of a pyrazolate‐based compartmental ligand with β‐diketiminato (nacnac) chelate arms (L − ), providing two pincer‐type {N 3 } binding pockets, has been reported to readily eliminate H 2 and to serve as a masked dinickel(I) species. Discrete dinickel(I) complexes ( 2 Na , 2 K ) of L − are now synthesized via a direct reduction route. They feature two adjacent T‐shaped metalloradicals that are antiferromagnetically coupled, giving an S =0 ground state. The two singly occupied local d x 2 - y 2type magnetic orbitals are oriented into the bimetallic cleft, enabling metal–metal cooperative 2 e − substrate reductions as shown by the rapid reaction with H 2 or O 2 . X‐ray crystallography reveals distinctly different positions of the K + in 1 K and 2 K , suggesting a stabilizing interaction of K + with the dihydride unit in 1 K . H 2 release from 1 K is triggered by peripheral γ‐C protonation at the nacnac subunits, which DFT calculations show lowers the barrier for reductive H 2 elimination from the bimetallic cleft.