The substitution reaction of (DTN)W2 (CO)10 with P(OCH(CH3 )2 )3 is a stepwise reaction. The kinetics of step 1 follow the equation: -d[substrate] /dt = kld [substrate] + k la [substrate] [ligand]. Thus the mechanism of step 1 is expected to be a competition between dissociative and associative pathways. The kinetics of step 2 follow the equation: -d[(DTN)W(CO)5]/dt = k2dk3[(DTN)W(CO)5][ligand]/k-2[DTN] + k3[ligand] The plot of kobsd versus [ligand] thus is a hyperbolic curve and the plot of 1/kobsd versus 1/[L] exhibits linear behavior. A mechanism for step 2 in which (DTN)W(CO)5 dissociates to an intermediate, W(CO) 5 , and in which DTN and P(OCH(CH3 )2 )3 compete to associate with W(CO) 5 is favored. The dissociative rate constant of the first step, kld' is about 1.2 times of that of the second step, k2d. The dissociation of (DTN)W(CO) 5 from (DTN)W2 (CO) 1 0 is favored over the dissociation of DTN from (DTN)W(CO) 5 due to a combination of the steric, stoichiometric, charge repulsion and entropy effects of the reaction.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc503931 |
| Date | 05 1900 |
| Creators | Yang, Sang-Nin |
| Contributors | Dobson, Gerard R., Theriot, L. J. |
| Publisher | North Texas State University |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | vi, 42 leaves: ill., Text |
| Rights | Public, Yang, Sang-Nin, Copyright, Copyright is held by the author, unless otherwise noted. All rights reserved. |
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