This thesis investigates the formation and subsequent coordination and reactivity of post d 10 metal cations, specifically cations of the group 11 metals and group 15 and 16 compounds. Cation formation is facilitated by abstraction of a chloride from the starting compound by Lewis acidic gallium trichloride or by exchange of the chloride by reaction with silver hexafluoroantimonate. Simple metal salts, MX (M = Cu, Au, X = Cl, M = Ag, X = OTt) were reacted with GaCl), generating cations in situ, and addition of P 4 yielded three new M -P 4 complexes. Copper and silver formed coordination polymers, whereas gold reacted to form a homoleptic cation, [Au(rrP4)2][GaCI4], in the first example of a white phosphorus complex of gold. The gold complex was particularly sensitive to air and moisture and thus stabilised cations were generated by the abstraction of a halide from ligated copper and gold complexes to further probe the M-P4 interaction. The coordination of white phosphorus yielded complexes of the type [LM(rrp4)][X] and the solid-state structures, characterised by X-ray crystallography, showed P 4 coordinated in 112- fashion in all instances. All the complexes showed the P 4 unit to be fluxional in solution, with the room temperature 3lpeH} NMR spectra showing broad peaks. At low temperatures, the fluxionality within the gold complexes was slowed on the NMR timescale and the peaks resolved into 2nd order splitting patterns. The dynamic behaviour of the P 4 unit coordinated to [LAu t was investigated computationally which revealed a dynamic pathway via a 11 1- transition state. The reactivities of the complexes were tested through a variety of experiments.