Which ligands would be exchanged in this reaction?
Complexes like $\ce{M(CO)5(solv)}$ are typically generated by photolysis ($\lambda$ = 350 nm) of $\ce{M(CO)6}$ in the presence of a non-inert solvent. This proceeds through a highly reactive "naked" $\ce{M(CO)5}$ intermediate.

$$\ce{W(CO)6 + solv -&gt;[h\nu] W(CO)5(solv) + CO}$$


When offered another ligand $\mathrm{L}$, the weakest bond  ligand in the $\ce{W(CO)5(solv)}$ complex is replaced. This is THF.
Taking the lone pair on the phosphorous atom into account, is is conceivable that $\ce{(CF3)2PH}$ will do the job:


$$\ce{W(CO)5(thf) + (CF3)2PH -&gt; W(CO)5((CF3)2PH) + THF}$$