| Autor: |
Lachguar A; Laboratory of Catalysis, Polymerization, Processes and Materials (CP2M UMR 5128), CNRS, Universite Claude Bernard Lyon 1, CPE-Lyon, Institut de Chimie de Lyon, 43 Bd du 11 Novembre 1918, Villeurbanne F-69616, France., Del Rosal I; CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 Avenue de Rangueil, Toulouse F-31077, France., Maron L; CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 Avenue de Rangueil, Toulouse F-31077, France., Jeanneau E; Centre de Diffractométrie Henri Longchambon, Université de Lyon, 5 Rue de la Doua, Villeurbanne 69100, France., Veyre L; Laboratory of Catalysis, Polymerization, Processes and Materials (CP2M UMR 5128), CNRS, Universite Claude Bernard Lyon 1, CPE-Lyon, Institut de Chimie de Lyon, 43 Bd du 11 Novembre 1918, Villeurbanne F-69616, France., Thieuleux C; Laboratory of Catalysis, Polymerization, Processes and Materials (CP2M UMR 5128), CNRS, Universite Claude Bernard Lyon 1, CPE-Lyon, Institut de Chimie de Lyon, 43 Bd du 11 Novembre 1918, Villeurbanne F-69616, France., Camp C; Laboratory of Catalysis, Polymerization, Processes and Materials (CP2M UMR 5128), CNRS, Universite Claude Bernard Lyon 1, CPE-Lyon, Institut de Chimie de Lyon, 43 Bd du 11 Novembre 1918, Villeurbanne F-69616, France. |
| Abstrakt: |
A salt metathesis synthetic strategy is used to access rare tantalum/coinage metal (Cu, Ag, Au) heterobimetallic complexes. Specifically, complex [Li(THF) 2 ][Ta(C t Bu)(CH 2 t Bu) 3 ], 1 , reacts with (IPr)MCl (M = Cu, Ag, Au, IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) to afford the alkylidyne-bridged species [Ta(CH 2 t Bu) 3 (μ-C t Bu)M(IPr)] 2-M . Interestingly, π-bonding of group 11 metals to the Ta─C moiety promotes a rare alkylidyne alkyl to bis-alkylidene tautomerism, in which compounds 2-M are in equilibrium with [Ta(CH t Bu)(CH 2 t Bu) 2 (μ-CH t Bu)M(IPr)] 3-M . This equilibrium was studied in detail using NMR spectroscopy and computational studies. This reveals that the equilibrium position is strongly dependent on the nature of the coinage metal going down the group 11 triad, thus offering a new valuable avenue for controlling this phenomenon. Furthermore, we show that these uncommon bimetallic couples could open attractive opportunities for synergistic reactivity. We notably report an uncommon deoxygenative carbyne transfer to CO 2 resulting in rare examples of coinage metal ketenyl species, ( t BuCCO)M(IPr), 4-M (M = Cu, Ag, Au). In the case of the Ta/Li analogue 1 , the bis(alkylidene) tautomer is not detected, and the reaction with CO 2 does not cleanly yield ketenyl species, which highlights the pivotal role played by the coinage metal partner in controlling these unconventional reactions. |
