This thesis encompasses two distinct areas of chemistry. The first part involves the synthesis and characterisation of phenylselenium(II) halides and pseudohalides and their further reactions with tertiary phosphines. The molecular structures of phenylselenium(II) chloride and thiocyanide are reported along with a large series of reactions involving phenylselenium(lI) chloride with tertiary phosphines. In addition to an extensive study of the products in solution using multinuclear NMR, suitable crystals were characterised using X-ray crystallography, yielding three novel crystal structures, two of which feature the rare [PhSeCI2] anion. The effect of doubling the starting quantity of phenylselenium(ll) chloride was noted to have the effect of encouraging more compounds containing the [R3PSePh] cation. The second part of the work incorporates the synthesis and characterisation of a series of hydrophobic bispidone - transition metal complexes. This study was the first example of bispidone ligands substituted with long alkyl chains and three novel crystal structures are reported. Their molecular configuration shows that each adopts the expected back-to-back double chair backbone as observed in similar studies by other chemists. Furthermore, the molecular structures of four piperidone precursor molecules were obtained, the first examples of piperidones substituted with hydrophobic alkyl chains. Their structures reveal that these molecules tautomerise in the solid state due to the formation of an intramolecular six-membered ring stabilised by hydrogen bonding.