| Autor: |
Feng, Xiuli, Li, Nan, Lv, Liqiang, King, R. Bruce |
| Předmět: |
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| Zdroj: |
New Journal of Chemistry; Sep2016, Vol. 40 Issue 9, p7482-7492, 11p |
| Abstrakt: |
The experimentally known CpFeMn(CO)7 system as well as the related unsaturated CpFeMn(CO)n systems (n = 6, 5) have been investigated by density functional theory. For CpFeMn(CO)7 unbridged and doubly bridged structures with a heteronuclear Fe–Mn single bond lie within ∼5 kcal mol−1 of each other with the experimentally known unbridged structure being the lower energy structure. The three lowest-energy unsaturated CpFeMn(CO)6 structures, lying within ∼1 kcal mol−1 of each other, have very diverse structural features. The lowest-energy CpFeMn(CO)6 structure contains an unusual three-center two-electron C–H–Mn bond involving an agostic hydrogen of the Cp ring. Another such structure is a triply bridged triplet CpFe(μ-CO)3Mn(CO)3 closely related to the experimentally known Cp2Fe2(μ-CO)3 having a central UGRAPHIC DISPLAY="INLINE" ID="UGT2" SRC="UGT2"/ Fe=Mn double bond containing the two unpaired electrons of the triplet spin state. The third low-energy CpFeMn(CO)6 structure is a CpFe(CO)Mn(CO)4(η2-μ-CO) structure with a four-electron donor bridging η2-μ-CO group similar to that found in the lowest energy Mn2(CO)9 structure. The lowest-energy structure of the even more unsaturated CpFeMn(CO)5 has a short Fe≡Mn distance of only ∼2.2 Å suggesting a formal triple bond. Higher energy CpFeMn(CO)5 structures have a four-electron donor η2-μ-CO group in addition to a formal Fe=Mn double bond. The CpFeMn(CO)5 structure in which the oxygen atom of the η2-μ-CO group is bonded to manganese lies ∼9 kcal mol−1 in energy below the isomeric structure in which the oxygen of the η2-μ-CO group is bonded to iron. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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