- Comparison of the Reactivity of Paracyclophane and p-Xylene
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The relative abilities of paracyclophane (C16H16) and p-xylene (C6H4Me2-1,4) to form arene tricarbonyl complexes from chromium hexacarbonyl has been studied in dioxane using the Strohmeier reflux method, and the rate constants contrasted.The reactions are found to proceed more quickly with paracyclophane by ca. 25percent.Density functional molecular-orbital calculations have rationalised this observation, and indicate that the enhanced reactivity of the paracyclophane system relative to p-xylene is a consequence of repulsive interactions between the two arene decks in the former, which are relieved to some extent by co-ordination of the electron-withdrawing Cr(CO)3 fragment.
- Dyson, Paul J.,Humphrey, David G.,McGrady, John E.,Mingos, D. Michael P.,Wilson, D. James
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p. 4039 - 4044
(2007/10/02)
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- METALLKOMPLEXE VON CYCLOPHANEN V. REAKTION VON 2,6,15,19-TETRATHIAPARACYCLOPHAN MIT Cr(CO)6. EINE NEUE MOEGLICHKEIT DER SCHWEFELEXTRUSION AUS EINEM THIAPHAN
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The reaction of 2,6,15,19-tetrathiaparacyclophane with Cr(CO)6 is described.The reaction products demonstrate the tendency of the 1,3-propanedithia unit to be cleaved off under the influence of the metal carbonyl.The reaction products allow a radical mechanism to be proposed for the elimination of the 1,3-propanedithia unit.
- Koray, Ali R.,Ziegler, Manfred L.
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