This Thesis describes the synthesis and characterisation of titanium hydrazido(2-) and alkylidene hydrazido(2-) complexes and their reactivity towards unsaturated molecules. Exploration of the bonding in titanium hydrazido(2-) and alkylidene hydrazido(2-) complexes is performed through structural and computational studies. Chapter 1 introduces current Group 4 hydrazido chemistry in comparison to Group 4 imido and mid/late metal hydrazido examples. Current Group 4 alkylidene hydrazido chemistry is also described. Chapter 2 describes the synthesis, bonding and the novel reaction chemistry of titanium hydrazido(2-) half-sandwich complexes. Novel reactivity at the Ti=N, bond is presented with the mechanisms of some of these transformations probed by Density Functional Theory (DFT) calculations. Chapter 3 describes the novel reaction chemistry of Cp*Ti{MeC(Nipr)2} (NNMe2) in comparison to its imido and diphenyl hydrazido analogues. Novel reactivity at both Ti=N, and Na-N~ bonds is presented with the mechanisms of some of these transformations probed by Density Functional Theory (DFT) calculations. Chapter 4 describes the synthesis and characterisation of a new titanium alkylidene hydrazido(2-) complex. The bonding of the alkylidene hydrazido(2-) ligand is explored through structural and computational studies. Novel reactivity at Ti=N, and Na-N~ bonds is presented. Chapter 5 presents full experimental procedures and characterising data for the new complexes reported. CD Appendix contains .cif files for all new crystallographically characterised complexes described.