Dr Alexander Steiner
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Main group, supramolecular and structural chemistry
1. Polyionic ring systems
We are interested in the development of new materials containing multianionic and multicationic phosphorus nitrogen scaffolds, such as those shown below. Multianionic ligands are able to accommodate large and well-defined arrays of metal ions. These systems offer interesting applications for polyelectrolytes and ion exchangers.
Selected references:
Tris(organozinc) phosphazenates as templates for trimeric and hexameric zinc oxide clusters.
R. Boomishankar, P. I. Richards, A. Steiner, Angew. Chem. Int. Ed. 2006, 45, 4632-4634
Zwitterionic phosphazenium phosphazenate ligands.
M. A. Benson, J. Ledger, A. Steiner, Chem. Commun. 2007, 3823-3825
The pentadecadentate phosphazenate [{2-(MeO)C6H4N}6P3N3]6-: Chelation of twelve lithium ions by a single ligand.
F, Rivals, A. Steiner, Chem. Commun. 2001, 1426-1427
From neutral iminophosphoranes to multianionic phosphazenates. The coordination chemistry of imino-aza-P(V) ligands.
A. Steiner, S. Zacchini, P. I. Richards, Coord. Chem. Rev. 2002, 227, 193-216
The N-donor stabilised cyclotriphosphazene hexacation [P3N3(DMAP)6]6+.
R. Boomishankar, J. Ledger, J.-B. Guilbaud, N. L. Campbell, J. Bacsa, R. Bonar-Law, Y. Z. Khimyak, A. Steiner, Chem. Commun. 2007, 5152-5154 
2. Supramolecular assemblies
We apply main group based molecules and ions as new building blocks for supramolecular assemblies. Molecular units that are built around p-block centres can offer unique spatial arrangements of supramolecular binding sites for novel network topologies. We also investigate new methods to fuse inorganic ring systems together in covalent fashion in order to generate extended polycyclic structures.
Selected references:
Supramolecular variations on a molecular theme: The structural diversity of phosphazenes (RNH)6P3N3 in the solid state.
J. F. Bickley, R. Bonar-Law, G. T. Lawson, P. I. Richards, F. Rivals, A. Steiner, S. Zacchini, Dalton Trans. 2003, 1235-1244
Cyclophosphazenes as Nodal Ligands in Coordination Polymers.
P.I. Richards, A. Steiner, Inorg. Chem. 2004, 43, 2810-2817
Connecting cyclophosphazenes via ring N-centres with covalent linkers.
M. A. Benson, A. Steiner, Chem. Commun. 2005, 43, 5026-5028
(hot paper)
A Spirocyclic System Comprising Both Phosphazane and Phosphazene Rings.
P.I. Richards, A. Steiner, Inorg. Chem. 2005, 44, 275-281
In-situ-complexation of inorganic lithium salts by amphiprotic cyclophosphazenes.
P. I. Richards, M. A. Benson, A. Steiner, Chem. Commun. 2003, 1392-1393
3. In-situ crystallisation
X-ray diffraction of single crystals is the prime technique for the determination of three-dimensional molecular structures. We apply in-situ crystallisation techniques in order to determine the solid state structures of compounds that are liquid at room temperature. In collaboration with Dr Neil Winterton we have obtained the crystal structures of a range of ionic liquids. We also discovered that specifically designed coordination polymers crystallise in-situ from amorphous materials into single crystals.
Selected references:
In-situ re-crystallisation of a coordination polymer with hemilabile linkers.
P. I. Richards, J. F. Bickley, R. Boomishankar, A. Steiner, Chem. Commun. 2008, 1656-1658
In-situ Crystallization of Low-Melting Ionic Liquids.
A. R. Choudhury, N. Winterton, A. Steiner, A. I. Cooper, K. A. Johnson, J. Am. Chem. Soc. 2005, 127, 16792-16793
In situ crystallization of ionic liquids with melting points below -25ºC.
A. R. Choudhury, N. Winterton, A. Steiner, A. I. Cooper, K. A. Johnson, CrystEngComm 2006, 8, 742-745
Biography
Dr Alexander Steiner obtained his Diplom in Chemistry in 1991 and his PhD in 1994 at the Universität Göttingen. After spending two years as a EU Marie Curie research fellow at Cambridge University he joined the staff at Liverpool in February 1997.