......................................................................................................................................6 ABBREVIATIONS – SPECTROSCOPIC .....................................................................................8 ABBREVIATIONS – UNITS...........................................................................................................8 ABBREVIATIONS – CHEMICAL.................................................................................................9 1. CHAPTER 1................................................................................................................................11 1.1 Bidentate Phosphine Ligands..................................................................................................11 1.2 Wide Bite Angle Diphosphines...............................................................................................13 1.3 Hydroformylation ...................................................................................................................17 1.4 Hydrocyanation.......................................................................................................................19 1.5 C-C Bond Formation from Alcohols ......................................................................................20 1.6 Synthesis and Characterisation of [Ru(P-P)(PPh3)(CO)H2] Precursors..................................27 1.7 Stoichiometric Reactivity of Benzyl Alcohol with 2 and 3 ....................................................29 1.8 Decarbonylation Studies .........................................................................................................35 1.9 Stoichiometric Reactivity of Benzaldehyde with 2 and 3 .......................................................36 1.10 Proposed Mechanism for the Catalyst Action of 2 in the Knoevenagel Reaction ................37 1.11 CHAPTER SUMMARY.......................................................................................................39 2. CHAPTER 2................................................................................................................................43 2.1 N-heterocyclic carbene (NHC) ligands...................................................................................43 2.2 Non-Innocent Behaviour of NHCs – C-H Bond Activation ...................................................48 2.3 Ruthenium NHC Complexes in C-C Bond Formation from Alcohols ...................................54 2.4 Spontaneous C-H Activation of NHCs on Reaction with [Ru(xantphos)(PPh3)(CO)H2] (2) .56 2.5 Interconversion of [Ru(xantphos)(NHC)'(CO)H] and [Ru(xantphos)(NHC)(CO)H2] ...........59 2.6 Treatment of [Ru(xantphos)(PPh3)(CO)H2] (2) with ICy .......................................................61 2.7 Activity of NHC-Xantphos Complexes in a Catalytic Knoevenagel Reaction.......................64 2.8 Efforts to Prepare New Hydrodefluorination Catalysts ..........................................................68 2.9 Synthesis of [Ru(xantphos)(PPh3)(CO)HF] (17) and Reaction with NHCs ...........................69 2.10 Synthesis and Characterisation of [Ru(xantphos)(NHC)(CO)HF] (NHC = ICy, IEt2Me2) ..72 2.11 Synthesis and Characterisation of [Ru(dppf)(ICy)(CO)H2] and [Ru(dppf)(ICy)(CO)HF]...73 2.12 Attempted Hydrodefluorination of C6F6 by [Ru(P-P)(NHC)(CO)H2] ..................................76 2.13 CHAPTER SUMMARY.......................................................................................................77 3. CHAPTER 3................................................................................................................................81