Reaction of cationic transition metal complexes with furan, thiophene, and pyrrole. Model studies relevant to hydrodeoxygenation, hydrodesulfurization, and hydrodenitrogenation

Conference · Fri Dec 01 04:00:00 EST 1995

OSTI ID:126627

Bakhtiar, R ^[1]; Jacobson, D B ^[2]

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1. Merck Research Labs., Rahway, NJ (United States)
2. North Dakota State Univ., Fargo, ND (United States)

Hydrodesulfurization, denitrogenation, and deoxygenation reactions are important reactions in many research areas such as the removal of nitrogen and sulfur from coal. In this report, reactions of Fe{sup +} and FeL{sup +} (L = O, C{sub 4}H{sub 6}, c-C{sub 5}H{sub 6}, c-C{sub 5}H{sub 6}, C{sub 6}H{sub 6}, C{sub 5}H{sub 4}(=CH{sub 2})) with thiophene, furan, and pyrrole in the gas phase by using Fourier transform mass spectrometry (FTMS) are described. Fe{sup +}, Fe(C{sub 5}H{sub 5}){sup +}, and FeC{sub 6}H{sub 6}{sup +} yield exclusive, rapid adduct formation with thiophene, furan, and pyrrole. The iron-diene complex FeC{sub 4}H{sub 6}{sup +}, Fe(c-C{sub 5}H{sub 6}){sup +}), as well as FeC{sub 5}H{sub 4}(=CH{sub 2}){sup +} and FeO{sup +} are quite reactive. An intriguing reaction is the predominant, direct extrusion of CO from furan by FeC{sub 4}H{sub 6}{sup +}, Fe(c-C{sub 5}H{sub 6}){sup +}, Fe(C{sub 5}H{sub 4}(=CH{sub 2}){sup +}. In addition, FeC{sub 4}H{sub 6}{sup +} and Fe(c-C{sub 5}H{sub 6}){sup +} yield minor amounts of HCN extrusion from pyrrole. The absence of CS extrusion from thiophene may be due to the higher energy requirements than that for CO extrusion from furan or HCN extrusion from pyrrole. The dominant reaction channel for reaction of Fe(c-C{sub 5}H{sub 6}){sup +} with pyrrole and thiophene is hydrogen atom displacement which implies D{sup 0}(Fe(C{sub 5}H{sub 5}){sup +}-C{sub 4}H{sub 4}X) > D{sup 0}(Fe(C{sub 5}H{sub 5}){sup +}-H) = 46 {+-} 5 kcal/mol. D{sup 0}(Fe{sup +}-C{sub 4}H{sub 4}S) and D{sup 0}(Fe{sup +}C{sub 4}H{sub 5}N) = D{sup 0}(Fe{sup +}-C{sub 4}H{sub 6}) = 48 {+-} 5 kcal/mol. Finally, D{sup 0}(Fe{sup +}-C{sub 4}H{sub 4}O) > D{sup 0}(Fe{sup +}-C{sub 2}H{sub 4}) = 39.9 {+-} 1.4 kcal/mol and D{sup 0}(Fe{sup +}-C{sub 4}H{sub 4}O) < D{sup 0}(Fe{sup +}-C{sub 6}H{sub 6}) = 55 {+-} 5 kcal/mol. FeO{sup +} reacts rapidly with thiophene, furan, and pyrrole to yield initial loss of CO followed by additional neutral losses.

• OSTI ID: 126627
• Report Number(s): CONF-950402--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
40 CHEMISTRY
ACTIVATION ENERGY
CHEMICAL BONDS
CHEMICAL REACTIONS
CLEAVAGE
COAL
DENITRATION
DESULFURIZATION
FURANS
IRON COMPLEXES
PYRROLES
THIOPHENE