Degree Name
Master of Science (MS)
Semester of Degree Completion
2001
Thesis Director
Richard L. Keiter
Abstract
The linkage isomers (CO)5W[η1-PPh2CH2PPhCH2PPh2], 1, and (CO)5 W[η1-PPh(CH2PPh2)2], 2, have been synthesized from the reaction of (OC)5W(NH2Ph) and Ph2PCH2PPhCH2PPh2. In addition, linkage isomers (CO)5W[μ-PPh2CH2PPhCH2PPh2]-W(CO)5, 3, and (CO)5W{μ-PPh2CH2PPh[W(CO)5] CH2PPh2}, 4, have been prepared. Attempts to obtain (OC)5WPPh2CH2PPh[W(CO)5]CH2PPh2W(CO)5 were unsuccessful, yielding instead (CO)5W[μ-η1,η2-PPh2CH2(PPhCH2PPh2)W(CO)4], 5, and (CO)5W[μ-η1, η2-PPh-(CH2PPh2)]W(CO)4, 8.
The isomerization reactions of (CO)5W[η1-PPh2CH2PPhCH2PPh2] and (CO)5 W[η1-PPh(CH2PPh2)2] were monitored independently by 31P{1H} NMR spectroscopy. Equilibrium constants and rate constants, k1 and k-1, for the isomerization were determined at 55°C, 40°C and 25°C.
A ΔS# value of -220 eu was found for the isomerization reaction, 2 ⇆ 1, is consistent with an associative 7-coordinate transition state and with a mechanism in which the dangling phosphine ligand interacts with the cis carbonyl groups to facilitate the reaction.
Recommended Citation
Gamage, Chaminda P., "Linkage Isomers of Tungsten Carbonyl Complexes of Ph₂PCH₂PPhCH₂PPh₂" (2001). Masters Theses. 1455.
https://thekeep.eiu.edu/theses/1455
