Unexpected reactions of 2,5-dimethylthiopene (2,5-Me{sub 2}t) in Cp{sup *}Ir({eta}{sup 5}-2,5-Me{sub 2}T){sup 2+}, Cp{sup *}Ir({eta}{sup 4}-2,5-Me{sub 2}T), and Cp{sup *}Ir(C,S-2,5-Me{sub 2}T) with cobaltocene
- Ames Lab., IA (United States)
The reaction of Cp{sup *}Ir({eta}{sup 5}-2,5-Me{sub 2}T){sup 2+} (1) (Cp{sup *} = {eta}{sup 5}-C{sub 5}Me{sub 5}) with the reducing agent Cp{sub 2}Co yields Cp{sup *}Ir({eta}{sup 4}-2,5-Me{sub 2}T) (2) and Cp{sup *}Ir(C,S-2,5-Me{sub 2}T) (3), as well as the unexpected Cp{sup *}Ir({eta}{sup 4}-2,5-Me{sub 2}T{center_dot}C{sub 5}H{sub 4}) (4), which can also be prepared by reacting 1 with Cp{sup -}. An X-ray diffraction study of 4 shows the {eta}{sup 4}-2,5-Me{sub 2}T{center_dot}C{sub 5}H{sub 5} ligand to be a ring-opened 2,5-Me{sub 2}T allyl thiolate conjugated to a cyclopentadienylidene unit. The reduced products 2 and 3 react with Cp{sub 2}Co to give a ferrole-type product Cp{sup *}[IrC(Me)=CHCH=C(Me)]CoCp in which the planar iridacyclopentadiene ring is {pi}-bonded to the cobalt, as established by a structural investigation. The Cp{sup *}Co analog of 5 is prepared by the reaction of 2 or 3 with Cp{sup *}Co(CH{sub 2}=CH{sub 2}){sub 2}. These studies demonstrate that cobaltocene and Cp{sup *}Co(CH{sub 2}=CH{sub 2}){sub 2} readily desulfurize the 2,5-dimethylthiophene ligand in 2 and 3, which supports a previously proposed mechanism for the thiophene hydrodesulfurization. 37 refs., 2 figs., 5 tabs.
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 226715
- Journal Information:
- Organometallics, Vol. 15, Issue 4; Other Information: PBD: 20 Feb 1996
- Country of Publication:
- United States
- Language:
- English
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