Synthese gemischt chalkogenido‐verbrückter Dirheniumkomplexe vom Typ Re2(μ‐ER)(μ‐E′R′)(CO)8 (E,E′ = S,Se, Te; R,R′ = org. Rest) |
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Authors: | Hans Egold,Ulrich Flö rke |
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Abstract: | Synthesis of Mixed Chalcogenido‐Bridged Dirhenium Complexes of the Type Re2(μ‐ER)(μ‐E′R′)(CO)8 (E, E′ = S, Se, Te; R, R′ = org. Residue) Hydrido sulfido bridged complexes Re2(μ‐H)(μ‐SR)(CO)8 (R = Ph, naph, Cy) react with the base DBU to give the salts [DBUH][Re2(μ‐SR)(CO)8]. Upon addition of electrophiles R′E′Br (E′R = SPh, SePh, TePh) to the in situ prepared salts mixed chalcogenido bridged complexes Re2(μ‐SR)(μ‐E′R′)(CO)8 were formed. The structures of the new compounds Re2(μ‐SCy)(μ‐SePh)(CO)8 and Re2(μ‐Snaph)(μ‐TePh)(CO)8 were determined by single crystal X‐ray analyses. For the preparation of analogous selenido tellurido bridged complexes Re2(μ‐SePh)(μ‐TeR)(CO)8 the novel hydrido selenido bridged complex Re2(μ‐H)(μ‐SePh)(CO)8 was prepared from Re2(CO)8(NCMe)2 and PhSeH. Its structure was determined by single crystal X‐ray analysis. Subsequent deprotonation with DBU gave in situ [DBUH][Re2(μ‐SePh)(CO)8] which upon addition of RTeBr (R = Ph, Bun, But) formed the desired complexes Re2(μ‐SePh)(μ‐TeR)(CO)8. The reaction with ButTeBr also yielded the novel spirocyclic complex (μ4‐Te){Re2(μ‐SePh)(CO)8}2 in low amounts. It was identified by single crystal X‐ray analysis. Re2(μ‐SePh)(μ‐TeBut)(CO)8 is oxidised in chloroform in the presence of air to give the novel complex (μ‐Te–Te‐μ){Re2(μ‐SePh)(CO)8}2. All mixed chalcogenido bridged dirhenium complexes were proved to be dynamic in solution by 13C NMR spectroscopy. The dynamic behaviour is based on the fast and permanent inversion of the sulfido and selenido bridges. The tellurido bridges are rigid on the time scale of 13C NMR spectroscopy. |
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Keywords: | Rhenium Metal carbonyl complexes Organochalcogenolato bridges Hydrido bridged complexes |
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