TY - JOUR
T1 - [Ni(NHC)2] as a Scaffold for Structurally Characterized trans [H-Ni-PR2] and trans [R2P-Ni-PR2] Complexes
AU - Sabater, Sara
AU - Schmidt, David
AU - Schmidt, Heidi
AU - Kuntze-Fechner, Maximilian W.
AU - Zell, Thomas
AU - Isaac, Connie J.
AU - Rajabi, Nasir Ahmad
AU - Grieve, Harry
AU - Blackaby, William J. M.
AU - Lowe, John P.
AU - Macgregor, Stuart Alan
AU - Mahon, Mary F.
AU - Radius, Udo
AU - Whittlesey, Michael K.
N1 - Funding Information:
We thank the Royal Society (Newton Fellowship to SS), EPSRC, the Deutsche Forschungsgemeinschaft (DFG; RA720/7), the Julius‐Maximilians‐Universität Würzburg and Heriot–Watt University for financial support.
Publisher Copyright:
© 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH
PY - 2021/9/15
Y1 - 2021/9/15
N2 - The addition of PPh2H, PPhMeH, PPhH2, P(para-Tol)H2, PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2] (NHC=IiPr2, IMe4, IEt2Me2) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR2] or novel trans [R2P−Ni−PR2] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4>IEt2Me2>IiPr2) and phosphines are employed. P−P activation of the diphosphines R2P−PR2 (R2=Ph2, PhMe) provides an alternative route to some of the [Ni(NHC)2(PR2)2] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)2(Ph2P−PPh2)] adducts proceeds with computed barriers below 10 kcal mol−1. The ability of the [Ni(NHC)2] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction.
AB - The addition of PPh2H, PPhMeH, PPhH2, P(para-Tol)H2, PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2] (NHC=IiPr2, IMe4, IEt2Me2) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR2] or novel trans [R2P−Ni−PR2] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4>IEt2Me2>IiPr2) and phosphines are employed. P−P activation of the diphosphines R2P−PR2 (R2=Ph2, PhMe) provides an alternative route to some of the [Ni(NHC)2(PR2)2] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)2(Ph2P−PPh2)] adducts proceeds with computed barriers below 10 kcal mol−1. The ability of the [Ni(NHC)2] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction.
KW - carbene ligands
KW - density functional calculations
KW - hydride ligands
KW - nickel
KW - phosphido ligands
UR - http://www.scopus.com/inward/record.url?scp=85111752826&partnerID=8YFLogxK
U2 - 10.1002/chem.202101484
DO - 10.1002/chem.202101484
M3 - Article
C2 - 34190374
SN - 0947-6539
VL - 27
SP - 13221
EP - 13234
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 52
ER -