Investigation of ligand steric effect on the hydrogen gas produced via a nickel-catalyzed dehydrogenation of ammonia-borane utilizing unsymmetrical triazolylidene ligands. (16th August 2016)

• Record Type: Journal Article
• Authors: Talbot, Meghan O.; Pham, Theresa N.; Guino-o, Marites A.; Guzei, Ilia A.; Vinokur, Anastasiya I.; Young, Victor G.
• Is Part Of: Polyhedron. Volume 114(2016)
• Page Start: 415
• Page End: 421
• Publication Date: 2016-08-16
• Subjects: Triazolylidene ligands -- Dehydrogenation -- Ammonia-borane -- Nickel-catalyzed -- Triazolium salts; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2016.02.034
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Seven new unsymmetrical triazolylidene ligands 4-(4-R-phenyl)-1-R′-1, 2, 4-triazoly-1-lidene (where R = H, CH3, CF3, F; and R′ = CH3, i Pr, Bzl, methylcyclohexane) were employed in a nickel-catalyzed dehydrogenation of ammonia borane. The ligand's reactivity is correlated to the steric bulk associated with the different R′ substitutions of the triazole using the solid angle G-parameter. Abstract: Seven new unsymmetrical triazolylidene ligands 4-(4-R-phenyl)-1-R′-1, 2, 4-triazoly-1-lidene (where R = H, CH3, CF3, F; and R′ = CH3, i Pr, Bzl, methylcyclohexane) were employed in a nickel-catalyzed dehydrogenation of ammonia borane to investigate the steric effects associated with the different N(1) substitutions in the triazole ring. The bulkier substituents benzyl and methylcyclohexane afforded the highest weight percent H2 gas produced. To quantify the steric effect, both percent buried volume (% V bur ) and solid angle G parameter (%) were employed. The G-parameter is a more useful tool when only the crystal structures of the precursor ligands are available.