Question

You are provided with a set of different ligands of the PR3 type and a large supply of (CO)5W(thf) with which to make a series of complexes in the form (CO)5W(PR3) by substitution of thf with PR3 how would you estimate the relative ordering of the electron donor power of the different PR3 ligands

Answer 1

Phosphines are weak bases, their main qualities decreases with the degree ofsubstitution: R₃P >> R₂PH > RPH₂. Trisubstituted phosphine ligandsexpressed very strong electron - donor properties.