Selectivity of Rh⋅⋅⋅H−C Binding in a σ-Alkane Complex Controlled by the Secondary Microenvironment in the Solid State

TY - JOUR

T1 - Selectivity of Rh⋅⋅⋅H−C Binding in a σ-Alkane Complex Controlled by the Secondary Microenvironment in the Solid State

AU - Furfari, Samantha K.

AU - Tegner, Bengt E.

AU - Burnage, Arron L.

AU - Doyle, Laurence R.

AU - Bukvic, Alexander J.

AU - Macgregor, Stuart A.

AU - Weller, Andrew S.

N1 - Funding Information: We are grateful to SCG Chemicals, the EPSRC (M024210) and the Leverhulme Trust (RPG‐2015‐447) for funding; Professor Neil Champness (University of Nottingham, UK) for useful discussions and alerting us to the use of CrystalExplorer to explore weak interactions in the solid state; and Dr José Manuel Menéndez (Heriot‐Watt) for excellent IT support. Publisher Copyright: © 2020 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH

PY - 2021/1/12

Y1 - 2021/1/12

N2 - By using single-crystal to single-crystal solid-state molecular organometallic (SMOM) techniques, the σ -alkane complex [Rh( t Bu 2 PCH 2 CH 2 CH 2 P t Bu 2 )( η 2 , η 2 -C 7 H 12 )][BAr F 4 ] (Ar F = 3,5-(CF 3 ) 2 C 6 H 3 ) is synthesized and structurally characterized, in which the alkane (norbornane) binds through two exo -C-H···Rh interactions. In contrast, the bis-cyclohexyl phosphine analogue shows endo -alkane binding. Comparison of the two systems, supported by periodic DFT calculations, NCI plots and Hirshfeld surface analyses, trace this different regioselectivity to subtle changes in the local microenvironment surrounding the alkane ligand. A tertiary periodic structure supporting a secondary microenvironment that controls binding at the metal site has parallels with enzymes. The new σ -alkane complex is also a catalyst for solid/gas 1-butene isomerization, and catalyst resting states are identified for this.

AB - By using single-crystal to single-crystal solid-state molecular organometallic (SMOM) techniques, the σ -alkane complex [Rh( t Bu 2 PCH 2 CH 2 CH 2 P t Bu 2 )( η 2 , η 2 -C 7 H 12 )][BAr F 4 ] (Ar F = 3,5-(CF 3 ) 2 C 6 H 3 ) is synthesized and structurally characterized, in which the alkane (norbornane) binds through two exo -C-H···Rh interactions. In contrast, the bis-cyclohexyl phosphine analogue shows endo -alkane binding. Comparison of the two systems, supported by periodic DFT calculations, NCI plots and Hirshfeld surface analyses, trace this different regioselectivity to subtle changes in the local microenvironment surrounding the alkane ligand. A tertiary periodic structure supporting a secondary microenvironment that controls binding at the metal site has parallels with enzymes. The new σ -alkane complex is also a catalyst for solid/gas 1-butene isomerization, and catalyst resting states are identified for this.

KW - density functional calculations

KW - isomerization

KW - periodic DFT

KW - rhodium

KW - selectivity

KW - SMOM

UR - http://www.scopus.com/inward/record.url?scp=85099307643&partnerID=8YFLogxK

U2 - 10.1002/chem.202004585

DO - 10.1002/chem.202004585

M3 - Article

C2 - 33112000

SN - 0947-6539

VL - 27

SP - 3177

EP - 3183

JO - Chemistry : A European Journal

JF - Chemistry : A European Journal

IS - 9

ER -