Prof. Lee Brammer

Biographical Sketch

Prof. Brammer obtained his BSc in Chemistry from the University of Bristol in 1983, which was followed by a PhD in Inorganic Chemistry from the same institution in 1987. After a NATO Postdoctoral Fellowship at the University of New Orleans (1987-88) and a Postdoctoral Fellowship at Brookhaven National Laboratory, New York (1989-90), he became an Assistant Professor and subsequently an Associate Professor at the University of Missouri-St. Louis (1990-2001). Since 2001 he has been in Sheffield, first as Reader, but since 2008 as Professor of Chemistry.

Research Keywords

Supramolecular chemistry, crystal engineering, solid-state chemistry, functional crystalline materials, intermolecular interactions (esp. hydrogen bonding and halogen bonding), reactions in molecular solids, X-ray and neutron diffraction, computational chemistry

Teaching Keywords

Solid State Chemistry; Crystallography

Selected Publications:

Synthesis and polymorphism of (4-ClpyH)₂[CuCl₄]: solid-gas and solid-solid reactions, I. J. Vitorica-Yrezabal, R. A. Sullivan, S. L. Purver, C. Curfs and L. Brammer, CrystEngComm 2011, 13, 3189-3196.
Energetics of Halogen Bonding of Group 10 Metal Fluoride Complexes, T. Beweries, L. Brammer, N. A. Jasim, J. E. McGrady, R. N. Perutz and A. C. Whitwood, J. Am. Chem. Soc. 2011, 133, 14338-14348.
Mechanistic Insights into a Gas-Solid Reaction in Molecular Crystals: The Role of Hydrogen Bonding, G. Minguez Espallargas, J. van de Streek, P. Fernandes, A. J. Florence, M. Brunelli, K. Shankland and L. Brammer, Angew Chem Int Edit 2010, 49, 8892-8896.
Rational Modification of the Hierarchy of Intermolecular Interactions in Molecular Crystal Structures by Using Tunable Halogen Bonds, G. M. Espallargas, F. Zordan, L. A. Marin, H. Adams, K. Shankland, J. van de Streek and L. Brammer, Chem-Eur J 2009, 15, 7554-7568.
Noncovalent interactions under extreme conditions: High-pressure and low-temperature diffraction studies of the isostructural metal-organic networks (4-chloropyridinium)₂[CoX₄] (X = CI, Br), G. Minguez Espallargas, L. Brammer, D. R. Allan, C. R. Pulham, N. Robertson and J. E. Warren, J. Am. Chem. Soc. 2008, 130, 9058-9071.
Metal fluorides form strong hydrogen bonds and halogen bonds: Measuring interaction enthalpies and entropies in solution, S. Libri, N. A. Jasim, R. N. Perutz and L. Brammer, J. Am. Chem. Soc. 2008, 130, 7842-7844.
Ligand substitution within nonporous crystals of a coordination polymer: Elimination from and insertion into Ag-O bonds by alcohol molecules in a solid-vapor reaction, S. Libri, M. Mahler, G. Minguez Espallargas, D. C. N. G. Singh, J. Soleimannejad, H. Adams, M. D. Burgard, N. P. Rath, M. Brunelli and L. Brammer, Angew Chem Int Edit 2008, 47, 1693-1697.
Reversible gas uptake by a nonporous crystalline solid involving multiple changes in covalent bonding, G. Minguez Espallargas, M. Hippler, A. J. Florence, P. Fernandes, J. van de Streek, M. Brunelli, W. I. F. David, K. Shankland and L. Brammer, J. Am. Chem. Soc. 2007, 129, 15606-15614.
Ligand flexibility and framework rearrangement in a new family of porous metal-organic frameworks, S. M. Hawxwell, G. M. Espallargas, D. Bradshaw, M. J. Rosseinsky, T. J. Prior, A. J. Florence, J. van de Streek and L. Brammer, Chem. Commun. 2007, 1532-1534.
Reversible extrusion and uptake of HCl molecules by crystalline solids involving coordination bond cleavage and formation, G. Minguez Espallargas, L. Brammer, J. van de Streek, K. Shankland, A. J. Florence and H. Adams, J. Am. Chem. Soc. 2006, 128, 9584-9585.
Designing intermolecular interactions between halogenated peripheries of inorganic and organic molecules: Electrostatically directed M-X···X '-C halogen bonds, G. Minguez Espallargas, L. Brammer and P. Sherwood, Angew Chem Int Edit 2006, 45, 435-440.
Supramolecular chemistry of halogens: Complementary features of inorganic (M-X) and organic (C-X ') halogens applied to M-X···X '-C halogen bond formation, F. Zordan, L. Brammer and P. Sherwood, J. Am. Chem. Soc. 2005, 127, 5979-5989.
Understanding the behavior of halogens as hydrogen bond acceptors, L. Brammer, E. A. Bruton and P. Sherwood, Cryst Growth Design 2001, 1, 277-290.

Selected Reviews and book chapters

“Combining metals with halogen bonds,” L. Brammer, G. Mínguez Espallargas and S. Libri, CrystEngComm, 2008, 10, 1712-1727.
“New trends in crystal engineering,” D. Braga, L. Brammer and N. R. Champness, CrystEngComm, 2005, 7, 1-19.
“Developments in inorganic crystal engineering,” L. Brammer, Chem. Soc. Rev., 2004, 34, 476-489.
“Metals and Hydrogen Bonds,” L. Brammer, Dalton Trans., 2003, 3145-3157. (Perspective article)
“Hydrogen Bonds in Inorganic Chemistry: Application to Crystal Design,” L. Brammer, in "Perspectives in Supramolecular Chemistry, Vol 7: Crystal Design – Structure and Function", ed. G. R. Desiraju, Wiley, 2003, pp 1-75.

Research Interests

Our current research can be divided, broadly speaking, into three areas: (i) inorganic supramolecular chemistry, (ii) porous coordination framework materials, and (iii) reactions in molecular crystals.

Inorganic Supramolecular Chemistry

Work in this area involves the use of transition metals to influence the construction and properties of supramolecular assemblies in the solid state (crystal engineering) and in solution. We have a number of ongoing projects in this area, but the principal focus is on (a) detailed study of intermolecular interactions using various experimental and computational methods, and (b) the application of the knowledge gained to the construction of network solids (infinite assemblies). Specific systems being studied include:

recognition of hydrogen bond donors by halometallate ions and use of halometallates as nodes in hydrogen bonded network construction;
linking coordination compounds or organometallic compounds into networks using peripherally situated ligand-centred hydrogen bonds;
understanding halogen bonding and the use of halogen bonding as a strong directional interaction that is a viable alternative to hydrogen bonding in supramolecular assembly.

Porous Coordination Framework Materials

Framework materials based upon coordination chemistry, often known as metal-organic frameworks (MOFs), provide a highly versatile alternative to well-established porous materials such as zeolites. Their synthesis is based upon molecular chemistry and they are typically constructed as crystalline network solids using metal centres as nodes which are linked via organic bridging ligands. Applications range from sorption and storage of gases (including hydrogen) and volatile pollutants, to host-guest chemistry for chemical separations and even catalysis. Current efforts in our group are focused on flexible, responsive materials and upon functionalised materials tailored to specific applications. Studies involve synthesis, characterisation by diffraction methods (single crystal, powder) and by a range of other techniques including thermal analyses and spectroscopy.

Facilities

Our research is based in excellent modern synthetic laboratories built in 2003, with an accompanying office suite for students and postdocs. The department maintains excellent instrumentation facilities for spectroscopy (NMR, IR, MS) and we have an outstanding X-ray diffraction facility that is crucial in characterisation of the crystalline materials that we study. We also make extensive use of major national and international facilities for diffraction, in particular high flux synchrotron X-ray facilities in the UK (Daresbury SRS and in future Diamond) and at the ESRF in Grenoble, France.

General

My general philosophy is to make use of a variety of approaches and techniques in pursuing research goals. A better overall understanding is developed by such an approach. Thus, students and postdocs have the opportunity to be exposed to many aspects of chemistry, while perhaps developing greater expertise or interests in certain aspects of a project. Many projects involve some synthesis of organic, organometallic and/or coordination compounds, and will involve supramolecular synthesis and/or materials synthesis methods (e.g. solvothermal synthesis). NMR and IR spectroscopy are widely employed and extensive use is made of diffraction methods, particularly single crystal and powder X-ray diffraction, but also neutron diffraction. Materials characterization methods (e.g. DSC, TGA) are also used where needed and computational chemistry is used to support efforts in other areas. Where appropriate the work is conducted within the research group, but collaborative efforts with other research groups have always proven important in our work. We have established collaborations in areas of synthetic and computational chemistry, diffraction and materials characterisation such as gas sorption and magnetic measurements. Such collaborations often provide opportunities for group members to visit and work in other research labs.

Teaching Section

Inorganic Chemistry

Undergraduate Courses Taught

CHM2104.4 "Introduction to solid state materials"
The course provides an introduction to the structural aspects of solid state chemistry. The description of crystalline solids in terms of lattices, unit cells and space group symmetry is discussed. Long range and short range order is discussed together with defects in crystalline materials. Band structure is introduced in the context of conduction in solids.
CHM3101.3 "Diffraction Techniques in Structural Chemistry"
The course provides an introduction to single crystal X-ray diffraction methods. Information that can be derived from this experimental method is identifies and the limitations of the technique are discussed. The course focuses on symmetry and periodicity, diffraction, structure determination, and the interpretation and evaluation of structural information in a chemical context.
CHM3102.1 "Inorganic Materials"
The course provides an overview of synthesis, structures and properties of selected inorganic materials. A survey of different methods of synthesis of materials is provided. The structures and applications of zeolites and related silicate materials are presented. The preparation and applications of semiconductor materials are introduced.
CHM4001.1/CHM4002.1/CHM4011.1: Supramolecular Chemistry 1
The properties of crystalline solids are derived from the collective properties of their molecular components governed by the crystal structure that describes the assembly of these components. Thus, control over crystal structure, namely crystal design and synthesis, offers the prospect of designer materials with designed properties. This course will provide an introduction to different types of intermolecular interactions that are commonly used in the design of crystalline materials composed of molecular building blocks. The strength, directionality and complementarity of these interactions are discussed. Examples are used to illustrate the design process for materials based upon non-covalent interactions (e.g. hydrogen bonds and halogen bonds) and upon coordination networks, the two most common means of designing crystalline materials. The synthesis and characterisation of these solid-state compounds is discussed. Applications of designed materials are presented, including non-linear optics, gas sorption and catalysis. With particular reference to biologically relevant systems, the issue of polymorphism, solvates and co-crystal formation will be discussed in the context of the pharmaceutical industry.

Tutorial & Workshop Support

First Year General Tutorials.
Second Year Inorganic Chemistry Tutorials.
Third Year Workshops (Diffraction Techniques, Inorganic Materials).
Third Year Literature Review.
Fourth Year Workshops (Supramolecular Chemistry).

Laboratory Teaching

Second Year Demonstrating
Third Year Laboratory Projects
Fourth Year Research Project

Professor of Inorganic and Solid State Chemistry