Imperial College London
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Dr F. Mark Chadwick

Faculty of Natural Sciences, Department of Chemistry

Research Fellow
 
 
 
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Contact

 

+44 (0)20 7594 5872m.chadwick

 
 
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Location

 

601KMolecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Pike:2014:10.1021/ja510437p,
author = {Pike, SD and Chadwick, FM and Rees, NH and Scott, MP and Weller, AS and Krämer, T and Macgregor, SA},
doi = {10.1021/ja510437p},
journal = {Journal of the American Chemical Society},
pages = {820--833},
title = {Solid-state synthesis and characterization of σ-Alkane complexes, [Rh(L2)(η2,η2-C7H12)][BArF4] (L2 = bidentate chelating phosphine)},
url = {http://dx.doi.org/10.1021/ja510437p},
volume = {137},
year = {2014}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The use of solid/gas and single-crystal to single-crystal synthetic routes is reported for the synthesis and characterization of a number of σ-alkane complexes: [Rh(R2P(CH2)nPR2)(η2,η2-C7H12)][BArF4]; R = Cy, n = 2; R = iPr, n = 2,3; Ar = 3,5-C6H3(CF3)2. These norbornane adducts are formed by simple hydrogenation of the corresponding norbornadiene precursor in the solid state. For R = Cy (n = 2), the resulting complex is remarkably stable (months at 298 K), allowing for full characterization using single-crystal X-ray diffraction. The solid-state structure shows no disorder, and the structural metrics can be accurately determined, while the 1H chemical shifts of the Rh···H–C motif can be determined using solid-state NMR spectroscopy. DFT calculations show that the bonding between the metal fragment and the alkane can be best characterized as a three-center, two-electron interaction, of which σCH → Rh donation is the major component. The other alkane complexes exhibit solid-state 31P NMR data consistent with their formation, but they are now much less persistent at 298 K and ultimately give the corresponding zwitterions in which [BArF4]− coordinates and NBA is lost. The solid-state structures, as determined by X-ray crystallography, for all these [BArF4]− adducts are reported. DFT calculations suggest that the molecular zwitterions within these structures are all significantly more stable than their corresponding σ-alkane cations, suggesting that the solid-state motif has a strong influence on their observed relative stabilities.
AU  - Pike,SD
AU  - Chadwick,FM
AU  - Rees,NH
AU  - Scott,MP
AU  - Weller,AS
AU  - Krämer,T
AU  - Macgregor,SA
DO  - 10.1021/ja510437p
EP  - 833
PY  - 2014///
SN  - 0002-7863
SP  - 820
TI  - Solid-state synthesis and characterization of σ-Alkane complexes, [Rh(L2)(η2,η2-C7H12)][BArF4] (L2 = bidentate chelating phosphine)
T2  - Journal of the American Chemical Society
UR  - http://dx.doi.org/10.1021/ja510437p
UR  - https://pubs.acs.org/doi/10.1021/ja510437p
UR  - http://hdl.handle.net/10044/1/40512
VL  - 137
ER  -
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