Article
Lithium Di-‐ and Trimethyl Dimolybdenum(II) Complexes with Mo-‐Mo Quadruple Bonds and Bridging Methyl Groups
Author/s | Curado, Natalia
Carrasco, Mario Álvarez González, Eleuterio Maya Díaz, Celia María Peloso, Riccardo Rodríguez, Amor López Serrano, Joaquín Carmona Guzmán, Ernesto |
Publication Date | 2015 |
Deposit Date | 2017-11-20 |
Published in |
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Abstract | New dimolybdenum complexes of composition [Mo2{μ-Me}2Li(S)}(μ- X)(μ-N^N)2] (3a−3c), where S = THF or Et2O and N^N represents a bidentate aminopyridinate or amidinate ligand that bridges the quadruply bonded molybdenum ... New dimolybdenum complexes of composition [Mo2{μ-Me}2Li(S)}(μ- X)(μ-N^N)2] (3a−3c), where S = THF or Et2O and N^N represents a bidentate aminopyridinate or amidinate ligand that bridges the quadruply bonded molybdenum atoms, were prepared from the reaction of the appropriate [Mo2{μ-O2CMe}2(μ-N^N)2] precursors and LiMe. For complex 3a, X = MeCO2, while in 3b and 3c, X = Me. Solution NMR studies in C6D6 solvent support formulation of the complexes as contact ion pairs with weak agostic Mo−CH3···Li interactions, which were also evidenced by X-ray crystallography in the solid-state structures of the molecules of 3a and 3b. Samples of 3c enriched in 13C (99%) at the metal-bonded methyl sites were also prepared and investigated by NMR spectroscopy employing C6D6 and THF-d8 solvents. Crystallization of 3c from toluene:tetrahydrofuran mixtures provided single crystals of the solvent separated ion pair complex [Li(THF)4] [Mo2(Me)2(μ-Me){μ-HC(NDipp)2}2] (4c), where Dipp stands for 2,6-iPr2C6H3. A computational analysis of the Mo2(μ-Me)2Li core of complexes 3a and 3b has been developed, which is consistent with a small but non-negligible electron-density sharing between the C and Li atoms of the mainly ionic CH3···Li interactions. |
Project ID. | CTQ2010-‐15833
CTQ2013-‐42501-‐P BES-‐2011-‐047643 CSD2007-‐00006 FQM-‐119 P09-‐FQM-‐5117 AP-‐4193 CTQ2014-‐52769-‐C3-‐3-‐R |
Citation | Curado, N., Carrasco, M., Álvarez, E., Maya, C., Peloso, R., Rodríguez, A.,...,Carmona, E. (2015). Lithium Di-‐ and Trimethyl Dimolybdenum(II) Complexes with Mo-‐Mo Quadruple Bonds and Bridging Methyl Groups. Journal of the American Chemical Society, 137 (38), 12378-12387. |
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