Design of Spin-Crossover Complexes for Chiral and Soft Molecular Materials

The focus of this thesis is the design of spin-crossover complexes for inclusion into chiral or soft materials. A variety of ligand and complex architectures have been investigated and a method for functionalising polymers with such complexes has been explored. Chapter 2 discusses the spin states of a family of homochiral and heterochiral iron(II) PyBox complexes in the solid state and in solution. Solution phase results show the first example of chiral discrimination between spin states, which is a promising development towards the incorporation of such complexes in functional materials. Chapter 3 provides a computational approach to these iron(II) PyBox complexes and reinforces the experimental data presented in Chapter 2. Further insights into the contribution of the PyBox ligands are discussed and predictions on the spin states of a family of analogous iron(II) thio-PyBox complexes are made. Chapter 4 is an investigation into cobalt(II) and zinc(II) PyBox complexes and looks at the speciation of these in solution and compares these trends to those seen in their iron(II) counterparts. In addition, NOESY NMR studies of the zinc(II) complexes and the magnetic behaviour of the cobalt(II) complexes are reviewed. Chapter 5 explores the structure and spin-crossover behaviour of a family of iron(II) tripodal pseudoclathrochelate complexes. During the synthesis, a pair of multimetallic clusters were serendipitously discovered, and these are also reviewed. Chapter 6 is an exploration into the incorporation of a functionalised bpp ligand into polymers. The RAFT polymerisation and copolymerisation of acrylates and this ligand derivative are presented. Chapter 7 details the synthetic procedures and analysis for each compound discussed in this thesis.