New Experimental Insight into the Nature of Metal−Metal Bonds in Digallium Compounds: J Coupling between Quadrupolar Nuclei. Issue 28 (8th June 2016)

• Record Type: Journal Article
• Authors: Kobera, Libor; Southern, Scott A.; Rao, Gyandshwar Kumar; Richeson, Darrin S.; Bryce, David L.
• Is Part Of: Chemistry. Volume 22:Issue 28(2016)
• Page Start: 9565
• Page End: 9573
• Publication Date: 2016-06-08
• Subjects: gallium -- gallyne -- J coupling -- multiple bonding -- NMR spectroscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201600999
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: 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. Abstract : Must be going Ga−Ga : The nature of gallium−gallium bonding is assessed by measuring J ( 71 Ga, 71 Ga) coupling constants by solid‐state NMR spectroscopy. These experimental data demonstrate that while Ga–Ga systems may feature multiple bonds, their electronic structure clearly differs from that established for analogous carbon−carbon or boron−boron bonds.