New Experimental Insight into the Nature of Metal-Metal Bonds in Digallium Compounds: J Coupling between Quadrupolar Nuclei.
Multiple bonding between atoms is of ongoing fundamental and applied interest. Here, we report a multinuclear ((1) H, (13) C, and (71) Ga) solid-state magnetic resonance spectroscopic study of digallium compounds which have been proposed, albeit somewhat controversially, to contain single, double, and triple Ga-Ga bonds. Of particular relevance to the nature of these bonds, we have carried out two-dimensional (71) Ga J/D-resolved NMR experiments which provide a direct measurement of J((71) Ga,(71) Ga) spin-spin coupling constants across the gallium-gallium bonds. When placed in the context of clear-cut experimental data for analogous singly, doubly, and triply bonded carbon spin pairs or boron spin pairs, the (71) Ga NMR data clearly support the notion of a different bonding paradigm in the gallium systems. Our findings are consistent with an increasing role across the purported gallane-gallene-gallyne series for classical and/or slipped π-type bonding orbitals.
Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Pvt. D'Iorio Hall, Ottawa, Ontario, K1N 6N5, Canada.
Libor
L
Kobera
Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Pvt. D'Iorio Hall, Ottawa, Ontario, K1N 6N5, Canada.
Scott A
SA
Southern
Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Pvt. D'Iorio Hall, Ottawa, Ontario, K1N 6N5, Canada.
Gyandshwar Kumar
GK
Rao
Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Pvt. D'Iorio Hall, Ottawa, Ontario, K1N 6N5, Canada.
Darrin S
DS
Richeson
Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Pvt. D'Iorio Hall, Ottawa, Ontario, K1N 6N5, Canada. dbryce@uottawa.ca.
David L
DL
Bryce
J coupling; NMR spectroscopy; gallium; gallyne; multiple bonding