Dirhenium complexes that contain the ligand 1,1-bis(diphenylphosphino)ethene (dppE). Synthesis, characterization and reactivity of Re2Cl4(mu-dppE)(2)

摘要

The dirhenium(II) compound Re2Cl4(mu-dppE)(2) (1), where dppE = (Ph2P)(2)C=CH2, which contains an electron-rich triple bond, has been prepared by the reaction of (n-Bu4N)(2)Re2Cl8 with CH3CO2Na and dppE in refluxing ethanol. Its reactivity towards CO alone, and CO in combination with XylNC and 2,5-Me-2-C6H3CN has been explored. The complexes Re2Cl4(mu-dppE)(2)(CO)(2) (2) and [Re2Cl3(mu-dppE)(2)(CO)(2)(L)]O3SCF3, where L = CO (3), XylNC (4) or 2,5-Me-2-C6H3CN (5) have been isolated and characterized by IR and NMR spectroscopy, cyclic voltammetry and X-ray crystallography. The complex trans -Re-2(mu-O2CCH3)(2)Cl-2(mu-dppE)(2) (6) has been obtained by the reaction of Re-2(mu-O2CCH3)(4)Cl-2 with dppE. Crystal structure determinations on 1, 2, 4 and 6 reveal that the Re-Re distances are 2.2448(5), 2.5748(5), 2.5767(5) and 2.2861(6) Angstrom, which are in accordance with Re-Re bond orders of 3, 2, 2 and 3, respectively. (C) 2000 Elsevier Science S.A. All rights reserved. [References: 33]