Collison, DavidWinpenny, RichardAlsuhaymi, Abdulelah2025-12-072025https://hdl.handle.net/20.500.14154/77322This thesis explores how the structures of polymetallic compounds can be directed by selecting carboxylic acids and templates. The work focuses on the synthesis of heterometallic rings using dipropylammonium or tetramethylammonium as templates, together with chromium(III) fluoride hydrate, a metal(II) carbonate source, and either 3,5-bis(trifluoromethyl)benzoic acid or 4-(trifluoromethyl)benzoic acid. The results demonstrate that both the template and carboxylate ligand play crucial roles in defining the final structures and properties. The introduction provides an overview of the literature on templated metallic complexes, cyclic metallic clusters, and heterometallic rings, as well as the synthetic methods used to construct these heterometallic rings. It also includes brief backgrounds on the principles of magnetism and the methodologies used in the project. Three new heterometallic rings, [Pr2NH2][(Pr2NH2)Cr6IIIM2IIF8(BTFB)16] (M = Ni, Co, or Zn; BTFB = 3,5-bis(trifluoromethyl)benzoate), were synthesised using a di-n-propylammonium template. Each ring has six Cr(III) and two M(II) ions in an octagonal arrangement bridged by fluoride and BTFB− ligands, with one ammonium cation inside the cavity and another outside. The disordered positions of M(II) centres lead to isomerism, evident from magnetic, EPR (M= Ni, Zn), and 19F-NMR (M = Co) data, indicating a roughly 1:1 mixture of 1,5- and 1,2- isomers. Using tetramethylammonium (Me₄N)+ as a template, a new heterometallic ring [Me4N][(Me4N)2Cr5Ni3F8(BTFB)16] was synthesised. The ring contains five Cr(III) and three adjacent Ni(II) centres at positions 1, 2, and 3 of an octagon, with each edge bridged by one fluoride and two BTFB ligands. Two ammonium cations lie above and below the metal plane, and one outside the ring. EPR data confirm an S = 1/2 ground state, consistent with the crystal structure. The synthesis of a new family of heterometallic rings using different templates with 4-(trifluoromethyl)benzoic acid is reported. The choice of template directs the formation of octametallic rings with varying {Cr7M} and {Cr6M2} compositions. The compounds were characterised by elemental analysis, IR, mass spectrometry, X-ray crystallography, magnetometry, EPR, and NMR spectroscopy.212enTemplate-directed assemblyHeterometallic ringsFluorinated benzoateMolecular magnetismEPR spectroscopyNMR spectroscopySingle-crystal XRDESI-mass spectrometryMagnetometryThesis