24554-49-2Relevant academic research and scientific papers
Relative phosphorus ligand sizes from cis:trans distributions of W(CO)4(L)(L′) products obtained from the reaction of W(CO)4(L) (py) with L′ (L and L′ = phosphines), reaction kinetics, and syntheses of starting materials
Boyles, Melissa L.,Brown, Daniel V.,Drake, Dennis A.,Hostetler, Cheryl K.,Maves, Constance K.,Mosbo, John A.
, p. 3126 - 3131 (2008/10/08)
The relative sizes of 12 phosphines (L′ = PMe3, PPhMe2, PEt3, P(n-Bu)3, PPh2Me, PPh2Et, PPh3, P(p-tol)3, PPh2(i-Pr), PPh2(t-Bu), PBz3, or PCy3) have been studied by determining cis:trans ratios of W(CO)4(L)(L′) products obtained from reactions of W(CO)4(L)(py) complexes with L′ (L = PPhMe2, PPh2Et, or P(p-tol)3). In general, a decrease in the cis:trans ratio was observed as the Tolman cone angle of L′ increased. Exceptions occurred with PEt3 and P(H-Bu)3, for which cone angles of 140-145°, rather than Tolman's value of 132°, would be consistent with the other ratio data. Kinetic studies of these reactions indicate that dissociative loss of pyridine is rate limiting. Also reported are the synthesis of W(CO)4(L)(py) from W(CO)4(py)2 and L and 31P NMR data for 21 new W(CO)4(L)(L′) complexes.
