Synthesis, structure, and thermochemistry of the formation of the metal-metal bonded dimers [Mo(μ-TeAr)(CO)3(PiP 3)]2 (Ar = phenyl, naphthyl) by phosphine elimination from •Mo(TePh)(CO)3(PiPr3) 2

Inorganic Chemistry

Volumn 46, Issue 3, 2007, Pages 652-659

  Weir, John J ^a   McDonough, James E ^a   Fortman, George ^a   Isrow, Derek ^a   Hoff, Carl D ^a   Scott, Brian ^a   Kubas, Gregory J ^a  

^a NONE

Author keywords

[No Author keywords available]

Indexed keywords

EID: 33847164464     PISSN: 00201669     EISSN: None     Source Type: Journal    
DOI: 10.1021/ic061654x     Document Type: Article

References (33)

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2. Transition Metal Sulfur Chemistry; Stiefel, E. I., Matsumoto, K., Eds.; ACS Symposium Series 653; American Chemical Society: Washington, DC, 1996.
3. 2) cation which retains a S-S bond and in which the methyl disulfides are symmetrically bound. (McKarns, P. J.; Heeg, M. J.; Winter, C. H. Inorg. Chem. 1998, 37, 4743.) The high oxidation state of Nb(V) presumably rules out oxidative addition.
4. Search of the Cambridge database yielded no structures in which a disulfide (RS-SR) bridges two metals with an intact S-S bond as in 2B. Structures in which the S-S unit with no R groups attached bridges two metals are more widely known. See, for example, Helton, M. E.; Chen, P.; Paul, P. P.; Tyeklar, Z.; Sommer, R. D.; Zakharov, L. N.; Rheingold, A. L.; Solomon, E. I.; Karlin, K. D. J. Am. Chem. Soc. 2003, 125, 1160.
5. 8 complexes was recently investigated theoretically: Aullon, G.; Hamidi, M.; Lledos, A.; Alvarez, S. Inorg. Chem. 2004, 43, 3702.
6. (a) Pasynskii, A. A.; Torubaer, Y. V.; Lyakina, A. Y.; Drukovskii, A. G.; Lyalikov, V. G.; Skabitskii, I. V.; Lysenko, K. A.; Nefedov, S. E. Russ. J. Coord. Chem. 1998, 24, 745.
7. (b) Pasynskii, A. A.; Torubaer, Y. V.; Drukovskii, A. V.; Eremenko, I. L.; Vegini, D.; Nefedov, S. E.; Dobrokhotova, A. V.; Yanovskii, A. I.; Struchkov, Y. T. Russ. J. Inorg. Chem. 1997, 42, 36.
8. (c) Pasynskii, A. A.; Torubaer, Y. V.; Drukovskii, A. V.; Eremenko, I. L.; Vegini, D.; Nefedov, S. E.; Dobrokhotova, A. V.; Yanovskii, A. I.; Struchkov, Y. T. Russ. J. Inorg. Chem. 1997, 42, 957.
9. (d) Pasynskii, A. A.; Torubaer, Y. V.; Drukovskii, A. V.; Eremenko, I. L.; Vegini, D.; Nefedov, S. E.; Dobrokhotova, A. V.; Yanovskii, A. I.; Struchkov, Y. T. Russ. J. Inorg. Chem. 1996, 41, 2006.
10. Llabres, P. G.; Dupont, O. D. Acta Crystallogr., Sect. B 1972, 28, 2438.
11. McDonough, J. E.; Weir, J. J.; Sukcharoenphon, K.; Hoff, C. D.; Kryatov, O. P.; Rybak-Akimova, E. V.; Scott, B.; Kubas, G. J.; Stephens, F. H.; Mendriatta, A.; Cummins, C. C. J. Am. Chem. Soc. 2006, 128, 10295.
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18. Deconvolution of the thermogram was accomplished by importing the data for the temperature/time profile of a fast reaction done under identical conditions, normalizing the initial maximum response to scale and using computer subtraction and integration to resolve the fast and slow components as relative fractions of the total heat. Experimental error to this procedure is not assigned since we rely instead on direct measurement by rapid response calorimetry of the fast first reaction. The agreement between the two approaches is good.
19. Mukerjee, S. L.; Gonzalez, A. A.; Nolan, S. P.; Ju, T. D.; Lang, R. F.; Hoff, C. D. Inorg. Chim. Acta 1995, 240, 175.
20. Amer, S.; Kramer, G.; Poe, A. J. Organomet. Chem. 1975, 220, 75.
21. An initial attempt at detecting this equilibrium in the temperature range -40 to -80°C in toluene appeared to show some spectroscopic changes; however, those results were never reproduced. On four separate attempts, the authors could find no conclusive evidence that the bands assigned to the monomeric radical complex associate in solution at low temperature.
22. Ju, T. D.; Capps, K. B.; Roper, G. C.; Hoff, C. D. Inorg.Chim. Acta 1998, 270, 488.
23. The subsequent steps leading to dimer formation could involve rearrangement of this radical, combination with the starting material, and ultimately production of product. These lead to complex rate laws which would be difficult to prove. The only conclusion that authors can make is that the radical recombination scheme in Figure 1 is not supported by our data, and a mechanism starting with a mononuclear reaction such as that shown in eq 6 mechanism could be supported.
24. (a) Hoff, C. D. Prog. Inorg. Chem. 1992, 40, 503.
25. 3 (unpublished results).
26. This estimate is based on use of the Sackur-Tetrode equation for translational entropy (see Stull, D. R.; Westrum, E. F., Jr.; Sinke, G. C. The Chemical Thermodynamics of Organic Compounds; Wiley: New York, 1969.
27. For an approximate application to reactions in solution see: Page, M. I. Angew. Chem., Int. Ed. Engl. 1977, 16, 449.
28. 2] as E goes from Te to Se to S.
29. Basolo, F. Polyhedron 1990, 9, 1503.
30. The reactions are pseudo-first-order in CO concentration, not in the usual sense that CO is present in large excess but in the sense that its concentration in solution does not change during the course of the reaction. That is due to the fact that the rate of uptake of CO from the gas phase to solution is rapid compared to the overall rate of reaction, and hence, a CO saturated solution is maintained at a constant [CO] throughout the course of the reaction leading to pseudo-first-order kinetics in [CO].
31. Fortman, G. C.; Isrow, D.; McDonough, J. E.; Weir, J. J.; Kiss, G.; Kubas, G. J.; Scott, B.; Hoff, C. D. Manuscript in preparation.
32. S-Centered Radicals; Alfassi, Z. B., Ed.; Wiley: New York, 1999.
33. 2 proceeds through dissociation to radicals or some other first step rather than through a mechanism similar to that shown in Figure 1. In spite of the importance of metal complex activation of the RE-ER bond, this remains a challenging mechanistic area even for E = O and certainly for the heavier cogeners.