Synthesis, Structure, and Redox Chemistry of Heteropolymetallic Carbon Complexes with MC2M', MC4M', and MC4M'C4M Linkages. Transmetalations of Lithiocarbon Complexes (.eta.5-C5Me5)Re(NO)(PPh3)(C.tplbond.CLi) and (.eta.5-C5Me5)Re(NO)(PPh3)(C.tplbond.CC.tplbond.CLi) Academic Article uri icon

abstract

  • Reactions of (η5-C5Me5)Re(NO)(PPh3)(C≡CLi) and trans-Pd(PEt3)2(Cl)2 or trans-Rh(PPh3)2(CO)(Cl) give heterobimetallic C2 complexes trans-(η5-C5Me5)Re(NO)(PPh3)(C≡C)Pd(PEt3)2(Cl) (3, 66%) or trans-(η5-C5Me5)-Re(NO)(PPh3)(C≡C)Ph(PPh3)2(CO) (4, 72%). Reaction of [η5-C5Me5)Re(NO)(PPh3)(ClC6H5)]+ BF4– and HC≡CC≡CSiMe3 gives [(η5-C5Me5)Re(NO)(PPh3)(HC≡CC≡CSiMe3)]+ BF4– (93%; HC≡C ligated), which with t-BuOK and K2CO3/MeOH yields (η5-C5Me5)Re(NO)(PPh3)(C≡CC≡CH) (9, 84%). Reaction of 9 and n-BuLi gives (η5-C5Me5)Re(NO)(PPh3)(C≡CC≡CLi) (10), which is trapped by MeI as (η5-C5Me5)Re(NO)(PPh3)(C≡CC≡CMe) (85%). Reaction of 10 and trans-Pd(PEt3)2(Cl)2 (2:1) gives trans-(η5-C5Me5)Re(NO)(PPh3)(C≡CC≡C)Pd-(PEt3)2(C≡CC≡C)(Ph3P)(ON)Re(η5-C5Me5) (12, 73%). At a 1:1 stoichiometry, trans-(η5-C5Me5)Re(NO)(PPh3)-(C≡CC≡C)Pd(PEt3)2(Cl) (13) is the major product. Cyclic voltammograms of 3, 12, and 13 show reversible one-electron oxidations. Reactions of 3 and 12 with (η5-C5H5)2Fe·+ PF6– give the radical cations 3·+ PF6– and 12·+ PF6–. These are unstable at room temperature, but ESR data show the odd electrons to be localized on (one) rhenium. Complexes 3 and 4 (but not 12 and 13) exhibit restricted rotation about the ReCxM moiety, as evidenced by two R3PMPR331P NMR signals at low temperature (ΔG‡(Tc) = 11.7–10.9 kcal/mol). The crystal structure of 3 shows eclipsed PEt3 ligands. © 1995, American Chemical Society. All rights reserved.

author list (cited authors)

  • Weng, W., Bartik, T., Brady, M., Bartik, B., Ramsden, J. A., Arif, A. M., & Gladysz, J. A.

citation count

  • 102

publication date

  • December 1995