Details of Grant 

EPSRC Reference:	GR/R16570/01
Title:	Bistable Magnetic Materials From Iron Dipyrazolypyridine Complexes
Principal Investigator:	Halcrow, Professor MA
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department:	Sch of Chemistry
Organisation:	University of Leeds
Scheme:	Standard Research (Pre-FEC)
Starts:	01 October 2001	Ends:	30 September 2004	Value (£):	77,638
EPSRC Research Topic Classifications:	Chemical Synthetic Methodology Materials Synthesis & Growth
EPSRC Industrial Sector Classifications:	Chemicals Electronics
Related Grants:
Panel History:
Summary on Grant Application Form
We have recently discovered that complexes of type [Fe(L1R)2]X2 (L1R = 3,3 -disubstituted-2,6-dipyrazolylpyridine; X- = monoanion) can be exist in high-spin, low-spin or spin-crossover forms at room temperature in the solid state or in solution, depending on the nature of the distal ligand 'R' substituents. Which spin state is adopted by the complex depends on both the steric and electronic properties of the ligand 'R' so that, in principle, a fine degree of control over the spin-crossover temperature of a Fe(11) centre is possible with this system. This project involves the synthesis of new derivatives of L1R bearing acidic or basic substituents, and their Fe(11) complexes. This will have two advantages over our initial systems. First, the electron-donating properties of the ligands can be finely tweaked by the protonation or deprotonation of the remote ligand substituents, to enforce a specific spin-crossover temperature onto our Fe(11) ion. Second, these ligands will facilitate intermolecular hydrogen bonding between the Fe(11) spins in the solid state. This is likely to lead to discontinuous (i.e. co-operative) spin-state transitions in the solid complexes, exhibiting a degree of thermal hysteresis. In this way, we expect to produce a crystalline compound that is bistable at room temperature. Since the first example of such a material was only published last year (in Science), this would represent a useful advance.
Key Findings
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Potential use in non-academic contexts
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Impacts
Description This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk Summary Date Materialised
Sectors submitted by the Researcher
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Project URL:
Further Information:
Organisation Website:	http://www.leeds.ac.uk