Oligophosphan-liganden XLII. Carbonyl(cyclopentadienyl) rheniumt(I) -Komplexe η1-C5H5Re(CO)3L2 mit fluktuierender sp3-und starrer sp2-Koordination des C5H5-rings1,2

Article abstract of DOI:10.1016/S0022-328X(96)06503-5

Combination of the halo rhenium(I) complexes fac-Re(CO)₃L₂X (L/X = PMe₃/Br (1), PPh₃/Cl (2), PCy₃/Br (3)), fac-Re(CO)₃(Ph₂PCH₂PPh₂)Br, 4, fac-Re(CO)₃[Ph₂P(CH₂)₂PR₂]Br (R = Me (5), Ph (6), Cy (7)), fac-Re(CO)₃[Ph₂P(CH₂)₃PPh₂]Cl, 8, and fac-Re(CO)₃[C₅H₈(PCy₂)₂]Br, 9 (C₅H₈(PCy₂)₂ = rac,trans-cyclopentan-1,2-diyl-bis(dicyclohexyl)phosphine), with Ag[O₃SCF₃] yielded fac-Re(CO)₃(PR₃)₂OSO₂CF₃ (R = Me (10), Ph (11), Cy (12)), fac-Re(CO)₃[R₂P(CH₂)_nPR₂]OSO₂CF₃ (n-1: R = Ph (13); n = 2: R = Me (14), Ph (15), Cy (16); n = 3: R = Ph (17)), and fac-Re(CO)₃[C₅H₈(PCy₂)₂]OSO₂CF₃, 18. Triflates 10, 11, and 14-17 were converted into cyclopentadienyl derivatives containing fluxional sp³-bonded C₅H₅ rings,fac-η¹-C₅H₅Re(CO)₃(PMe₃)₂, 19, fac-η¹-C₅H₅Re(CO)₃[R₂P(CH₂)_nPR₂] (n = 2: R = Me (20), Ph (21), Cy (22); n = 3: R = Ph (23)), and mer,trans-η¹-C₅H₅Re(CO)₃(PPh₃)₂, 24, when allowed to interact with Na[C₅H₅] in THF. Treatment of 18 with Na[C₅H₅] produced fac-η¹-C₅H₅Re(CO)₃[C₅H₈(PCy₂)₂] as a mixture of three isomers with the rhenium atom in the allylic position of a fluxional sp³-bonded rings (25a) or in the two vinylic sites of an sp²-bonded rigid C₅H₅ system, where the CH₂ group is either α or β to the metalated carbon atom (25b, 25c). η⁵-C₅H₅Re(CO)₃ and fac-[Re(CO)₃(Ph₂PCH₂PPh₂-P,P′)(Ph₂PCH₂PPh₂-P)]⁺ were identified as the only organometallic complexes resulting from interaction of triflates 12 and 13 with Na[C₅H₅]. The structure of fac-η¹-C₅H₅Re(CO)₃[Ph₂P(CH₂)₂PPh₂] -2CH₂Cl₂ was determined by single-crystal X-ray diffractometry.