Preparation and structure of the 17-electron (eta(5)-C5R5)Mo(OH)(2)(dppe) (R = Me, Et) organometallic compounds containing two gem-terminal hydroxideligands

Oxidation of (eta(5)-C5R5)MoH3(dppe) (R = Me, Et) by Cp2Fe+ in wet THF lead s to the formation of the corresponding (eta(5)-C5R5)Mo(OH)(2)(dppe). These compounds show a low-potential reversible oxidation wave. The structure of the C5Et5 complex has been confirmed by X-ray diffraction methods: triclin ic; space group <P(1)over bar >; a =11.030(1); b = 12.533(1); c = 16.241 (1 ) Angstrom; alpha = 68.585(7); beta = 75.197(5); gamma = 83.991(7)degrees; V = 2020.6(3) Angstrom(3); Z = 2; D-calc = 1.324 g cm(-3), mu(Mo-K-alpha) = 0.441 mm(-1); R-1 = 0.0325; wR(2) = 0.0875 for 415 parameters and 6823 ind ependent reflections [R-int = 0.0177] with I = 2 sigma(I). The molecule sho ws a four-legged piano-stool geometry with two terminal OH ligands in a rel ative trans configuration. The complex EPR properties indicate that an equi librium mixture of various species is present in solution. (C) 2000 Elsevie r Science S.A. All rights reserved.