Ring-opening of {sigma}-thienyl and {sigma}-furyl ligands at ditungsten (M=M) centers
- Indiana Univ., Bloomington, IN (United States)
A series of compounds of formula 1,2-M{sub 2}({sigma}-Th){sub 2}(NMe{sub 2}){sub 4}, 1,has been prepared, where M = Mo and/or W and Th = 2-thienyl[2-Th], 3-thienyl[3-Th], 5-methyl-2-thienyl[2,5-MeTh], and 2-benzothienyl[2-BTh]. Addition of {sup t}BuOH or CF{sub 3}Me{sub 2}COH to hydrocarbon solutions of 1, where M = W, lead to ring-opened products, 2, when the thienyl ligand is attached via the 2-carbon position. No ring-opening occurs for 3-thienyl derivatives. W{sub 2}(OR){sub 5}({mu}-CCH{sub 2}CHCHS)({sigma}-2-Th), 2, where one of the 2-thienyl rings has been opened, has been fully characterized and shown to be derived from a ring-opened {mu}-vinylidene intermediate W{sub 24}/(O{sup t}Bu){sub 4}({mu}-CCHCHCHS)({sigma}-2-Th). The compound W{sub 2}({sigma}-2-Fu){sub 2}(NMe{sub 2}){sub 4} was prepared and characterized (2-Fu = 2-furyl) and shown to undergo ring-opening in its reaction with {sup t}BuOH to give W{sub 2}(O{sup t}Bu){sub 5}({mu}-CCH{sub 2}CHCHO)({sigma}-2-Fu), 4, in an analogous manner to the 2-Th complex. The complexes 1 (M = W, 2-Th), 2, 3, and 4 have been characterized by single crystal X-ray studies. The results described herein are compared to other ring-opening reactions of S, N, and O organic heterocyclic compounds as models for the activation of S, N, and O containing fossil fuels in hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and hydrodeoxygenation (HDO) processes. 36 refs., 7 figs., 5 tabs.
- OSTI ID:
- 466309
- Journal Information:
- Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 7 Vol. 119; ISSN JACSAT; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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