5374
Organometallics 2006, 25, 5374-5380
Dimolybdenum-Tin Derivatives of the Unsaturated Hydride [Mo2(η5-C5H5)2(µ-H)(µ-PCy2)(CO)2] and HSnR3 (R ) Ph, Bu): Bridging versus Terminal Coordination of the Triorganostannyl Group M. Angeles Alvarez, M. Esther Garcı´a, Alberto Ramos, and Miguel A. Ruiz* Departamento de Quı´mica Orga´ nica e Inorga´ nica/IUQOEM, UniVersidad de OViedo, E-33071 OViedo, Spain ReceiVed June 5, 2006
Reaction of the 30-electron hydride [Mo2Cp2(µ-H)(µ-PCy2)(CO)2] with HSnR3 (Cp ) η5-C5H5; R ) Ph, Bu) leads to the unsaturated dimolybdenum-tin derivatives [Mo2Cp2(µ-PCy2)(µ-SnR3)(CO)2] (R ) Ph, Bu), which display a triorganostannyl ligand unusually bridging two metal atoms, and to the phosphinehydride complex [Mo2Cp2(µ-H)(SnPh3)(CO)2(PCy2H)], which has a formally triple Mo-Mo bond bridged by only one hydride ligand. The structures of the triphenylstannyl compounds were determined by singlecrystal X-ray diffraction studies, which revealed the presence of short Mo-Mo separations (2σ(I) R indexes (I >2σ(I))a R indexes (all data)a GOF no. of restraints/ params ∆F(max, min), e Å-3
3
5
C42H49Mo2O2PSn 927.35 monoclinic P21/c 0.71073 11.427(2) 18.567(3) 18.542(3) 90 105.488(3) 90 3791.1(11) 4 1.625 1.382 120 1.58 to 28.27 -15, 14; 0, 24; 0, 24 31 998 9184 [Rint ) 0.0555] 6104
C44H47Mo2O4PSn 981.36 monoclinic P21/n 0.71073 11.7278(19) 14.627(2) 22.860(4) 90 97.054(3) 90 3891.8(11) 4 1.675 1.355 120 1.66 to 28.28 -15, 15; 0, 19; 0, 29 36 644 9421 [Rint ) 0.1317] 5056
R1 ) 0.0383, wR2 ) 0.0710b R1 ) 0.0848, wR2 ) 0.0899b 1.073 0/549
R1 ) 0.0608, wR2 ) 0.1156c R1 ) 0.1584, wR2 ) 0.1581c 1.016 0/465
1.091, -1.094
1.168, -1.566
R1 ) ∑||Fo| - |Fc||/∑|Fo|. wR2 ) [∑w(|Fo|2 - |Fc|2)2/∑w|Fo|2]1/2; w ) 1/[σ2(Fo2) + (aP)2 + bP] where P ) (Fo2 + 2Fc2)/3. b a ) 0.0157, b ) 17.1043. c a ) 0.0230, b ) 55.2232. a
least-squares refinements, but all the methylenic hydrogen atoms were fixed at calculated geometric positions, to reach a satisfactory convergence. All hydrogen atoms were given an overall isotropic thermal parameter. X-ray Structure Determination of Compound 5. Collection of data, structure solution, and refinements were done as described for 3 (Table 4). For compound 5 the Cp ligand bonded to Mo(1) was found disordered over two positions related by rotation about the Mo-Cg vector, in which Cg represents the center of the Cp ring; the almost equal occupancy factors given (0.52 and 0.48) provided satisfactory refinement. All non-hydrogen atoms were refined anisotropically, with the exception of those C atoms of the disordered Cp ring, which were refined isotropically because they were persistently nonpositive definite. Because of the low quality of the diffraction data, only some hydrogen atoms could be found on difference maps, so all were fixed at calculated geometric positions in the last cycles of refinement, and they were given an overall isotropic thermal parameter.
Acknowledgment. We thank the MEC of Spain for a Ph.D. grant (to A.R.) and the MCYT for financial support (BQU200305471). Supporting Information Available: Crystallographic data for the structural analysis of compounds 3 and 5 in CIF format. This material is available free of charge via the Internet at http:// pubs.acs.org. OM060495M
