Dr Bruce Tattershall
Lecturer in Chemistry (retired)
Identification
by NMR of polyphosphorus ring and cage compounds.
Research Interests
Since a first publication in this field in 1984, we have discovered many
new polycyclic or cage compounds based on the P4 tetrahedron.
These have included new phosphorus halides, such as P4Br2
or P7I3, and derivatives of several new phosphorus
chalcogenide skeletons such as P5S2X or P3Se4X,
as well as a wide range of compounds P4E3XY based
on the previously known two P4S3I2 skeletons.
E may be any combination of sulfur and selenium, and X and Y are halide,
pseudohalide or a range of N-, O-, P- or S-centred organic groups.
Few of these compounds have been isolatable, because of ring-opening polymerisation,
so positive identification has been by complete analysis of 31P
spectra, or of 77Se spectra where present, of the compounds
in solution. This required accumulation of a detailed knowledge of
the relationships between molecular structure and the systems of NMR coupling
constants and chemical shifts observed within the cage skeletons.
We have shown that this knowledge is transferable from known to new cage
skeletons, enabling their identification. Apart from a few crystal
structures in this field, knowledge of molecular structure comes from ab
initio calculations, which I continue to carry out, and which often
yield useful predictions of relative NMR chemical shifts, as an aid to
their assignment. My published structural models may be found at
the website above, as may my freely downloadable software for the simulation
or fitting of NMR spectra, as well as software for use in teaching about
mass spectrum isotope patterns or molecular orbitals.
Our most recent publications have been the first studies of phosphorus
sulfide skeletons with chiral substituents. We were able to
use diastereomeric differences in NMR properties to assign absolute configurations,
and to model bond rotamers which were observed at low temperature.
Selected Publications
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B.W. Tattershall and E.L. Sandham. Interdependence of 31-Phosphorus-77-Selenium
NMR Coupling Constants in Bicyclic Phosphorus Selenide Compounds.
J. Chem. Soc., Dalton Trans., 2001, 1834-1840.
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B.W. Tattershall, R.W. Houghton and D.J. Martin. Polycyclic Phosphorus
Sulfide Compounds containing Chiral Amido or Imido Substituents.
Z. Anorg. Allgem. Chem., 2004, 630, 1991-1998.
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B.W. Tattershall. Assignment of Phosphorus NMR Parameters to Absolute
Configurations in Chiral Phosphorus Sulfide Cage Compounds, using Ab
Initio Methods. Z. Anorg. Allgem. Chem., 2005, 631, 1627-1632.
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B.W. Tattershall, J.G. Knight, M.J. Andrews and C.L. Booth. Phosphorus
NMR Characterisation of P`N Bond Rotamers of a a-P4S3
Amide with a Conformationally Constrained Chiral Substituent. Z.
Anorg. Allgem. Chem., 2006, 632, 425-432.
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B.W. Tattershall, J.G. Knight and M.J. Andrews. Phosphorus NMR and
Ab Initio Modelling of P`N Bond Rotamers of a Sterically Crowded
Chiral b-P4S3 Diamide. Z. Anorg. Allgem.
Chem., 2007, 633, 1442-1450.