73047-26-4Relevant academic research and scientific papers
A 31P Nuclear Magnetic Resonance Investigation of the Structure, Equilibria, and Kinetics of in Solution
Mann, Brian E.,Musco, Alfredo
, p. 776 - 785 (1980)
The compounds (L = PMe3, PMe2Ph, PMePh2, PEt3 or PBun3), n3, P(p-tolyl)3, P(CH2Ph)3, PPri3, or P(C6H11)3>, and i3, P(C6H11)3, or PBut2Ph> have been prepared and shown to exist in solution.In the cases of L = PMePh2, PEt3, PBun3, n = 3 and L = PPri3, P(C6H11)3, n = 2 it has proved possible to measure the equilibrium constant, ΔH, and ΔS for n+1>n> + L.For , , , , n3)4>, i3)3> and 3>, the tertiary phosphine exchange is dissociative, while for 13)2> and 2> associative exchange occurs.In the case of and n3)3> both associative and dissociative exchange occur, the relative rates of which depend on the temperature and concentration of free tertiary phosphine.In the cases of i3)2> and2> a marked solvent effect has been found and attributed to possible toluene co-ordination producing in equlibrium with .No evidence is found for steric crowding affecting ΔH or ΔH++, but ΔS and ΔS++ are affected due to interpenetration of the ligands and resulting loss of motional freedom, while previously it has been assumed that interligand steric crowding destabilizes the molecule via enthalpy term.
